light-emitting device

Abstract

Light-emitting device with bottom-emission structure, comprising: a substrate; a transistor, comprising: a first insulating layer over the substrate; an oxide semiconductor layer above the first insulating layer; a source electrode, a drain electrode and a gate electrode above the oxide semiconductor layer; and a second insulating layer over the oxide semiconductor layer, the source electrode and the drain electrode; an anode across the transistor; a first light-emitting element configured to emit light through a first color layer, so that blue light is extracted from the light-emitting device to the outside; a second light-emitting element configured to emit light through a second color layer, so that green light is extracted from the light-emitting device to the outside; a third light-emitting element configured to emit light through a third color layer, so that red light is extracted from the light-emitting device to the outside; a fourth light-emitting element, where: one of the source electrodes and the drain electrode is electrically connected to the anode, the anode is configured in such a way that it acts as the first electrode of one of the first to fourth light-emitting elements, the first to fourth light-emitting elements have the same structure comprising a first EL layer and a second EL layer with an intermediate charge-generating layer, The first EL layer contains a fluorescent substance that emits blue light, and the second EL layer contains a phosphorescent substance that emits yellow light.

Description

Technical field

[0001] The present invention relates to a light-emitting device. State of the art

[0002] It is anticipated that a light-emitting element incorporating an organic compound as a luminescent material, and exhibiting features such as thinness, lightness, fast response times, and low-voltage DC operation, will be applied to a next-generation flat panel display. In particular, a light-emitting device in which light-emitting elements are arranged in a matrix is ​​expected to offer advantages over a conventional liquid crystal display device in that it provides a wide viewing angle and excellent visibility.

[0003] The light emission mechanism of a light-emitting element is said to be as follows: When a voltage is applied between a pair of electrodes, with an EL layer containing a phosphor between them, electrons injected from the cathode and holes injected from the anode recombine in the light emission center of the EL layer to form molecular excitons. When these molecular excitons return to the ground state, energy is released and light is emitted. Singlet and triplet excitation are known as excitation states, and light emission is thought to be possible through either excitation state.

[0004] In order to improve the properties of a light-emitting device that includes such light-emitting elements, improvements to the element structure, the development of materials and the like have been actively carried out (see, for example, patent documents 1 to 5 and publication 1). [References] [Patent Document 1] JP 2010 - 182699 A [Patent document 2] US 2014 / 0 175 470 A1 [Patent document 3] US 2012 / 0 243 219 A1 [Patent document 4] US 2014 / 0 042 469 A1 [Patent document 5] US 2004 / 0 124 766 A1 [Publication 1] Lee et al., Journal of the Society for Information Display, 2009, 17(2), 151-157. Disclosure of the invention

[0005] When developing a light-emitting device (LED), reducing the drive voltage or current is a key factor in achieving lower power consumption. In addition to device structures where the carrier balance in the EL layer can be controlled or the recombination probability improved, the emission properties of the EL layer itself are also crucial for reducing the drive voltage or current. Therefore, it is essential to lower the drive voltage or current by enhancing the emission properties of the EL layer through the use of a suitable structure.The light-emitting element preferably exhibits both high reliability and a lower drive voltage.

[0006] In this sense, one embodiment of the present invention provides a light-emitting device with low power consumption. Another embodiment of the present invention provides a light-emitting device with low power consumption and high reliability. A further embodiment of the present invention provides a novel light-emitting device. It should be noted that the description of these problems does not preclude the existence of further problems. Not all problems need to be fulfilled in one embodiment of the present invention. Further problems will be apparent from the explanation of the description, the drawings, the claims, and the like, and can be derived from them.

[0007] One embodiment of the present invention is a light-emitting device with a bottom-emission structure, comprising: a substrate; a transistor comprising: a first insulating layer over the substrate; an oxide semiconductor layer over the first insulating layer; a source electrode, a drain electrode, and a gate electrode over the oxide semiconductor layer; and a second insulating layer over the oxide semiconductor layer, the source electrode, and the drain electrode; an anode over the transistor; a first light-emitting element configured to emit light through a first color layer, such that blue light is extracted from the light-emitting device to the outside; a second light-emitting element configured to emit light through a second color layer, such that green light is extracted from the light-emitting device to the outside;a third light-emitting element configured to emit light through a third color layer, such that red light is extracted from the light-emitting device to the outside; a fourth light-emitting element; wherein: one of the source electrodes and the drain electrode are electrically connected to the anode; the anode is configured to act as the first electrode of one of the first to fourth light-emitting elements; the first to fourth light-emitting elements have the same structure comprising a first EL layer and a second EL layer with an intermediate charge-generating layer; the first EL layer contains a fluorescent substance that emits blue light;and the second EL layer contains a phosphorescent substance that emits yellow light. Preferably, the fluorescent substance is an organic compound in which two benzo[b]naphtho[1,2-d]furanylamine skeletons are each independently bonded to a pyrene skeleton.

[0008] Another embodiment of the present invention is a light-emitting device with a bottom-emission structure, comprising: a substrate; a transistor comprising: a first insulating layer over the substrate; an oxide semiconductor layer over the first insulating layer; a source electrode, a drain electrode, and a gate electrode over the oxide semiconductor layer; and a second insulating layer over the oxide semiconductor layer, the source electrode, and the drain electrode; an anode over the transistor; a first light-emitting element configured to emit light through a first color layer, such that blue light is extracted from the light-emitting device to the outside; a second light-emitting element configured to emit light through a second color layer, such that green light is extracted from the light-emitting device to the outside;a third light-emitting element configured to emit light through a third color layer, such that red light is extracted from the light-emitting device to the outside; and a fourth light-emitting element, wherein: one of the source electrodes and the drain electrode are electrically connected to the anode; the anode is configured to act as the first electrode of one of the first to fourth light-emitting elements; the first light-emitting element comprises a first EL layer and a second EL layer with an intermediate charge-generating layer; the second to fourth light-emitting elements comprise the first EL layer and the second EL layer with the intermediate charge-generating layer; the first EL layer contains a first light-emitting layer that emits blue light;and the second EL layer contains a second light-emitting layer that emits yellow light. The first EL layer preferably contains an organic compound in which two benzo[b]naphtho[1,2-d]furanylamine skeletons are each independently bonded to a pyrene skeleton.

[0009] Another embodiment of the present invention is a light-emitting device with a bottom-emission structure, comprising: a plurality of pixels, one of the plurality of pixels comprising: a transistor over a substrate, the transistor comprising: an oxide semiconductor layer over a first insulating layer; a gate electrode over the oxide semiconductor layer; a source electrode and a drain electrode electrically connected to the oxide semiconductor layer; and a second insulating layer over the oxide semiconductor layer, the source electrode, and the drain electrode; an anode over the transistor; a first EL layer configured to emit one selected of blue light and yellow light; a second EL layer configured to emit another selected of blue light and yellow light;and a charge-generating layer between the first EL layer and the second EL layer, wherein: a first light-emitting element comprising the first EL layer, the charge-generating layer, and the second EL layer is configured to emit light through a first color layer, such that blue light is extracted from the light-emitting device to the outside; a second light-emitting element comprising the first EL layer, the charge-generating layer, and the second EL layer is configured to emit light through a second color layer, such that green light is extracted from the light-emitting device to the outside; a third light-emitting element comprising the first EL layer, the charge-generating layer, and the second EL layer is configured to emit light through a third color layer, such that red light is extracted from the light-emitting device to the outside;A fourth light-emitting element, comprising the first EL layer, the charge-generating layer, and the second EL layer, is configured to emit light from the light-emitting device to the outside; the light emitted from the light-emitting device by the fourth light-emitting element is obtained by combining one selected blue and yellow light emitted by the first EL layer and the other selected blue and yellow light emitted by the second EL layer; one of the source electrodes and the drain electrode are electrically connected to the anode; and the anode is configured to function as the first electrode of one of the first to fourth light-emitting elements. The first EL layer preferably contains an organic compound in which two benzo[b]naphtho[1,2-d]furanylamine frameworks are each independently bonded to a pyrene framework.

[0010] In the light-emitting device with one of the above structures, it is particularly preferred that the two benzo[b]naphtho[1,2-d]furanylamine frameworks are each bonded to the 1-position and the 6-position of the pyrene framework, respectively.

[0011] In the light-emitting device with one of the above structures, it is further preferred that each of the nitrogen atoms in the two benzo[b]naphtho[1,2-d]furanylamine frameworks is independently bonded to the 6-position or the 8-position of a benzo[b]naphtho[1,2-d]furanyl group.

[0012] In preferred embodiments, the first EL layer contains a first organic compound represented by a general formula (G1).

[0013] In the general formula (G1) Ar 1 and Ar 2Each independently represents a substituted or unsubstituted aryl group with 6 to 13 carbon atoms forming a ring, and R 1 to R 8 , R 10 to R 18 and R 20 to R 28 Each independently represents hydrogen, a substituted or unsubstituted alkyl group with 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 6 carbon atoms, a cyano group, a halogen, a substituted or unsubstituted haloalkyl group with 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group with 6 to 10 carbon atoms.

[0014] In further preferred embodiments, the first EL layer contains a first organic compound represented by a general formula (G2).

[0015] In the general formula (G2) R 1 to R 8 and R 29 to R38 each independently represents hydrogen, a substituted or unsubstituted alkyl group with 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 6 carbon atoms, a cyano group, a halogen, a substituted or unsubstituted haloalkyl group with 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group with 6 to 10 carbon atoms.

[0016] In preferred embodiments, the first EL layer contains a first organic compound, which is represented by a structural formula (132).

[0017] According to one embodiment of the present invention, a novel light-emitting device can be provided. Furthermore, a light-emitting device with low power consumption can be provided. Additionally, a light-emitting device with low power consumption and high reliability can be provided. It should be noted that the description of these effects does not preclude the existence of further effects. An embodiment of the present invention need not necessarily achieve all of the above-mentioned effects. Further effects will be apparent from the explanation of the description, the drawings, the claims, and the like, and can be derived from them. Brief description of the drawings Fig. 1A and Fig. 1B each represents a light-emitting element. Fig. Figure 2 shows a light emission mechanism of a light-emitting element. Fig. Figure 3 shows a light emission mechanism of a light-emitting element. Fig. Figure 4 shows a light emission mechanism of a light-emitting element. Fig. 5 represents a light-emitting device. Fig. 6A and Fig. 6B represents a light-emitting device. Fig. 7A, Fig. 7B, Fig. 7C, Fig. 7D, Fig. 7D'-1 and Fig. 7D'-2 represent electronic devices. Fig. 8A to Fig. 8C represents an electronic device. Fig. 9 represents lighting devices. Fig. 10 represents a light-emitting device. Fig. 11A and Fig. Figure 11B represents an example of a touchscreen embodiment. Fig. 12A and Fig. Figure 12B represents an example of a touchscreen embodiment. Fig. 13A and Fig. Figure 13B represents an example of a touchscreen embodiment. Fig. 14A and Fig. 14B are a block diagram and a flowchart of a touch sensor. Fig. Figure 15 is a circuit diagram of a touch sensor. Fig. Figure 16 shows luminance-current density properties of light-emitting elements 1 to 3. Fig. Figure 17 shows the power efficiency-luminance properties of the light-emitting elements 1 to 3. Fig. Figure 18 shows the luminance-voltage properties of the light-emitting elements 1 to 3. Fig. Figure 19 shows the current-voltage properties of the light-emitting elements 1 to 3. Fig. Figure 20 shows chromaticity coordinates of the light-emitting elements 1 to 3. Fig. Figure 21 shows luminance-current density properties of light-emitting comparison elements 1 to 3. Fig. Figure 22 shows the power efficiency-luminance properties of the light-emitting comparison elements 1 to 3. Fig. Figure 23 shows the luminance-voltage properties of the light-emitting comparison elements 1 to 3. Fig. Figure 24 shows the current-voltage properties of the light-emitting comparison elements 1 to 3. Fig. Figure 25 shows chromaticity coordinates of the light-emitting comparison elements 1 to 3. Fig. Figure 26 shows an emission spectrum of 1,6BnfAPrn-O3 in a toluene solution of 1,6BnfAPrn-O3. Fig. Figure 27 represents a structure of a light-emitting element. Fig. Figure 28 shows luminance-current density properties of light-emitting elements 4 to 7. Fig. Figure 29 shows the power efficiency-luminance properties of the light-emitting elements 4 to 7. Fig. Figure 30 shows luminance-voltage properties of the light-emitting elements 4 to 7. Fig. Figure 31 shows current-voltage properties of the light-emitting elements 4 to 7. Fig. Figure 32 shows chromaticity coordinates of the light-emitting elements 4 to 7. Fig. Figure 33 shows luminance-current density properties of light-emitting comparison elements 4 to 6. Fig. Figure 34 shows the power efficiency-luminance properties of the light-emitting comparison elements 4 to 6. Fig. Figure 35 shows luminance-voltage properties of the light-emitting comparison elements 4 to 6. Fig. Figure 36 shows current-voltage properties of the light-emitting comparison elements 4 to 6. Fig. Figure 37 shows an example of a light-emitting device. Fig. Figure 38 shows a comparison of power consumption. Fig. Figure 39 shows luminance-current density properties of light-emitting elements 8 and 9. Fig. Figure 40 shows the power efficiency-luminance properties of the light-emitting elements 8 and 9. Fig. Figure 41 shows luminance-voltage properties of the light-emitting elements 8 and 9. Fig. Figure 42 shows the current-voltage properties of the light-emitting elements 8 and 9. Fig. Figure 43 shows emission spectra of the light-emitting elements 8 and 9. Fig. Figure 44 shows the time dependence of the normalized luminance of the light-emitting elements 8 and 9. Best method for implementing the invention

[0018] The subject matter of the present invention is defined by the claims and the following statements serve to explain it.

[0019] It should be noted that the terms "film" and "layer" can be used interchangeably depending on the situation or circumstances. For example, in some cases the term "conducting film" may be used instead of the term "conducting layer," and the term "insulating layer" may be used instead of the term "insulating film." (Version 1)

[0020] A light-emitting device uses a light-emitting element (LE) in which an EL layer, containing a light-emitting layer, is provided between a pair of electrodes. Various structures can be used for the LEM; for example, a single EL layer can be provided between a pair of electrodes (single structure), or a multiple EL layers can be stacked on top of each other with a charge-generating layer between them (tandem structure). As an example of an LEM structure, a tandem LEM comprising two EL layers is described below. Fig. 1A described.

[0021] The in Fig. The light-emitting element shown in Figure 1A has a structure in which two EL layers (103a and 103b), each containing a light-emitting layer, are provided between a pair of electrodes (a first electrode 101 and a second electrode 102). In EL layer 103a, a hole injection layer 104a, a hole transport layer 105a, a light-emitting layer 106a, an electron transport layer 107a, an electron injection layer 108a, and the like are arranged one above the other over the first electrode 101. In EL layer 103b, a hole injection layer 104b, a hole transport layer 105b, a light-emitting layer 106b, an electron transport layer 107b, an electron injection layer 108b, and the like are arranged one above the other over the first electrode 101. A charge generation layer 109 is provided between the EL layer 103a and the EL layer 103b.

[0022] The light-emitting layers (106a and 106b) each contain a variety of substances, such as light-emitting substances, in a suitable combination and can emit fluorescence or phosphorescence in a desired emission color. It should be noted that a light-emitting layer containing a light-emitting substance different from that of light-emitting layer 106a or 106b may also be provided on light-emitting layer 106a or 106b.

[0023] The charge-generating layer 109 has a function for injecting electrons into one of the EL layers (103a or 103b) and for injecting holes into the other of the EL layers (103a or 103b) when a voltage is applied between the first electrode 101 and the second electrode 102. Therefore, injected into Fig. 1A the charge generation layer 109 electrons into the EL layer 103a and holes into the EL layer 103b when a voltage is applied such that the potential of the first electrode 101 is higher than that of the second electrode 102.

[0024] It should be noted that, with regard to light extraction efficiency, the charge-generating layer 109 preferably transmits visible light (specifically, the charge-generating layer 109 has a visible light transmittance of 40% or more). The charge-generating layer 109 functions even if it has a lower conductivity than the first electrode 101 or the second electrode 102.

[0025] At the in Fig. In the light-emitting element shown in Figure 1A, light emitted in all directions from the light-emitting layers (106a and 106b) in the EL layers (103a and 103b) is brought into resonance by the first electrode (reflective electrode) 101 and the second electrode (semi-transparent and semi-reflective electrode) 102, which serve as an optical microresonator (microcavity and microcavity, respectively). Light is emitted through the second electrode 102. The first electrode 101 is a reflective electrode with a multilayer structure consisting of a reflective conductive material and a transparent conductive material. Optical matching of this electrode is achieved by controlling the thickness of the transparent conductive film. Optical matching can also be achieved by controlling the thickness of the hole injection layer 104a in the EL layer 103a.

[0026] As described above, the optical adjustment is carried out by controlling the thickness of the first electrode 101 or the hole injection layer 104a, which allows spectra of a variety of beams of monochromatic light obtained from the light-emitting layers (106a and 106b) to be narrower and enables light emission with high color purity to be obtained.

[0027] At the in Fig. The optical path length of the light-emitting element shown in Figure 1A is the optical path length between the second electrode 102, which acts as a semi-transparent and semi-reflective electrode, and a light-emitting region in the EL layer 103b that is closest to the second electrode 102, preferably less than λ / 4, where λ is the wavelength of light emitted by the light-emitting region. Here, the light-emitting region denotes a region where holes and electrons recombine. With such a structure, standard white light can be produced by combining a plurality of beams of monochromatic light from the light-emitting layers (106a and 106b) of the element shown in Figure 1A. Fig. The light-emitting element shown in 1A can be obtained. The light-emitting layers (106a and 106b) emit, for example, blue light (e.g., with a peak in the emission spectrum in the range of 400 nm to 480 nm, preferably in the range of 450 nm to 470 nm), green light (e.g., with a peak in the emission spectrum in the range of 500 nm to 560 nm, preferably in the range of 520 nm to 555 nm), red light (e.g., with a peak in the emission spectrum in the range of 580 nm to 680 nm, preferably in the range of 600 nm to 620 nm), orange light (e.g., with a peak in the emission spectrum in the range of 580 nm to 610 nm, preferably in the range of 600 nm to 610 nm), or yellow light (e.g., with a peak in the emission spectrum in the range of 555 nm to 590 nm, preferably in the range of 570 nm to 580 nm).Furthermore, the following can be specified as concrete combinations of the emission colors of the light-emitting layers 106a and 106b (106a / 106b): blue / green, blue / yellow, blue / red, green / blue, green / yellow, green / red, red / blue, red / green and red / yellow.

[0028] Next, a specific example will be described in which the aforementioned light-emitting element is manufactured.

[0029] The first electrode 101 is a reflective electrode and is therefore designed using a conductive material with reflectivity, and a film is used whose reflectivity for visible light is higher than or equal to 40% and lower than or equal to 100%, preferably higher than or equal to 70% and lower than or equal to 100%, and whose resistivity is 1 × 10 -2Ωcm or lower. The second electrode 102 is formed using a conductive material with reflectivity and a conductive material that is transparent, and a film is used whose reflectivity for visible light is higher than or equal to 20% and lower than or equal to 80%, preferably higher than or equal to 40% and lower than or equal to 70%, and whose resistivity is 1 × 10 -2 Ωcm or lower.

[0030] The optical path length between the first electrode 101 and the second electrode 102 is adjusted for each light with a desired wavelength, so that light with a desired wavelength is brought into resonance by the light-emitting layers (106a and 106b) and can be amplified. In particular, the thickness of the transparent conductive film used for part of the first electrode 101 is changed so that the distance between the electrodes is mλ / 2 (m is a natural number), where λ is the desired wavelength of light.

[0031] Furthermore, the optical path lengths between the first electrode 101 and the light-emitting layers (106a and 106b), which emit light of a desired wavelength, are adjusted to amplify the light of a desired wavelength. In particular, the thickness of the transparent conductive film that can be used for part of the first electrode 101, or the thickness of an organic film that forms the hole injection layer 104a, is changed so that the optical path length is (2m'+1)λ / 4 (m' is a natural number), where λ is the desired wavelength of light.

[0032] In this case, the optical path length between the first electrode 101 and the second electrode 102 is more precisely represented by the total thickness from a reflection region in the first electrode 101 to a reflection region in the second electrode 102. However, it is difficult to determine the reflection regions in the first electrode 101 and the second electrode 102 precisely; therefore, it is assumed that the above effect can be obtained to a sufficient degree wherever the reflection regions in the first electrode 101 and the second electrode 102 are located. Furthermore, the optical path length between the first electrode 101 and the light-emitting layer that emits the desired light is, more precisely, the optical path length between the reflection region in the first electrode 101 and the light-emitting region in the light-emitting layer that emits the desired light.However, it is difficult to precisely determine the reflection area in the first electrode 101 and the light-emitting area in the light-emitting layer that emits the desired light; therefore, it is assumed that the above effect can be obtained to a sufficient degree wherever the reflection area and the light-emitting area are located in the first electrode 101 and the light-emitting layer that emits the desired light.

[0033] Any metals, alloys, electrically conductive compounds, mixtures thereof, and the like can be used for the first electrode 101 and the second electrode 102, depending on requirements. Specific examples include indium oxide-tin oxide (indium tin oxide), indium oxide-tin oxide containing silicon or silicon oxide, indium oxide-zinc oxide (indium zinc oxide), indium oxide containing tungsten oxide and zinc oxide, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), and titanium (Ti). Furthermore, an element belonging to Group 1 or Group 2 of the periodic table, for example, an alkali metal such as lithium (Li) or cesium (Cs), an alkaline earth metal such as... B. Calcium (Ca) or strontium (Sr), magnesium (Mg), an alloy containing such an element (MgAg, AlLi), a rare earth metal, such asEuropium (Eu) or ytterbium (Yb), an alloy containing such an element, graphene, and the like can be used. The first electrode 101 and the second electrode 102 can be formed, for example, by a sputtering process or an evaporation process (including a vacuum evaporation process).

[0034] The hole injection layers (104a and 104b) inject holes into the light-emitting layers (106a and 106b) through the hole transport layers (105a and 105b) with high hole transport properties and can be formed using an acceptor material such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, or manganese oxide. Alternatively, the hole injection layers (104a and 104b) can be formed using a phthalocyanine-based compound, such as phthalocyanine (abbreviation: H₂Pc) or copper phthalocyanine (abbreviation: CuPc), an aromatic amine compound, such as... B. 4,4'-Bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB) or N,N'-Bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD), a compound containing an electron-withdrawing group (a halogen or a cyano group), such as7,7,8,8-Tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil or 2,3,6,7,10,11-Hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), or an organic acceptor material, such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (abbreviation: PEDOT / PSS).

[0035] The hole injection layers (104a and 104b) can contain a hole transport material and an acceptor substance. If the hole injection layers (104a and 104b) contain a hole transport material and an acceptor substance, electrons are extracted from the hole transport material by the acceptor substance to create holes, and the holes are injected through the hole transport layers (105a and 105b) into the light-emitting layers (106a and 106b). The hole transport layers (105a and 105b) are formed using a hole transport material.

[0036] Specific examples of the hole transport material used for the hole injection layers (104a and 104b) and the hole transport layers (105a and 105b) include aromatic amine compounds, such as... B. 4,4'-Bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD), N,N'-Bis(3-methylphenyl)-N,N'-diphenyl-[1,1'biphenyl]-4,4'-diamine (abbreviation: TPD), 4,4',4''-Tris(carbazol-9-yl)triphenylamine (abbreviation: TCTA), 4,4',4''-Tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4',4''-Tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: MTDATA) and 4,4'-Bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB); 3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1); 3,6-Bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2) and 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1). Other examples include carbazole derivatives, such as...4,4'-Di(N-carbazolyl)biphenyl (abbreviation: CBP), 1,3,5-Tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), and 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA). The substances listed here are mainly those exhibiting a hole mobility of 10. -6 cm 2 exhibiting / Vs or higher. It should be noted that any substance other than those listed here can be used, as long as its hole transport property is higher than its electron transport property.

[0037] Other examples include high-molecular-weight compounds such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), Poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA) and Poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD).

[0038] Examples of the acceptor material used for the hole transport layers (105a and 105b) include the above acceptor material and an organic acceptor material. Among these, an oxide of a metal belonging to one of groups 4 to 8 of the periodic table is preferably used; in particular, molybdenum oxide is preferably used.

[0039] The light-emitting layers (106a and 106b) each contain a light-emitting substance. In addition to the light-emitting substance, each light-emitting layer (106a and 106b) contains an electron transport material, which is an organic compound, and / or a hole transport material. In the light-emitting element, one of the light-emitting layers (106a and 106b) contains a fluorescent substance whose emission spectrum in a toluene solution of the fluorescent substance has a peak wavelength of 440 nm to 460 nm, preferably 440 nm to 455 nm, or an organic compound in which two benzo[b]naphtho[1,2-d]furanylamine frameworks are bonded to a pyrene framework. The emission spectrum of the fluorescent substance preferably has a full width at half maximum (FWHM) of greater than or equal to 20 nm and less than or equal to 50 nm.

[0040] For example, a fluorescent substance whose emission spectrum in a toluene solution exhibits a peak wavelength of 440 nm to 460 nm is preferably used. More preferably, a substance with a pyrenediamine framework is used. More precisely, the substance with a pyrenediamine framework is preferably an organic compound in which two benzo[b]naphtho[1,2-d]furanylamine frameworks are bonded to a pyrene framework and which is represented by the following general formula (G1). It should be noted that the fluorescent substance that can be used in this embodiment is not limited to the following example.

[0041] An organic compound represented by the following general formula (G1) can be used as an organic compound in which two benzo[b]naphtho[1,2-d]furanylamine skeletons are bonded to a pyrene skeleton. It should be noted that the organic compound represented by the following general formula (G1) emits blue fluorescence.

[0042] In the general formula (G1) Ar 1 and Ar 2 Each independently represents a substituted or unsubstituted aryl group with 6 to 13 carbon atoms forming a ring, and R 1 to R 8 , R 10 to R 18 and R 20 to R 28Each independently represents hydrogen, a substituted or unsubstituted alkyl group with 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 6 carbon atoms, a cyano group, a halogen, a substituted or unsubstituted haloalkyl group with 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group with 6 to 10 carbon atoms.

[0043] For specific examples of the organic compound represented by the general formula (G1), reference can be made to embodiment 2.

[0044] There is no particular restriction regarding a material that can be used as a light-emitting substance for the other of the light-emitting layers (106a and 106b), and a light-emitting material that converts the singlet excitation energy into light emission in a region of visible light, or a light-emitting material that converts the triplet excitation energy into light emission in a region of visible light, can be used.

[0045] As an example of a light-emitting material that converts singlet excitation energy into light emission in the visible light range, a fluorescent substance can be cited. Examples of fluorescent substances include a pyrene derivative, anthracene derivative, a triphenylene derivative, a fluorene derivative, a carbazole derivative, a dibenzothiophene derivative, a dibenzofuran derivative, a dibenzoquinoxaline derivative, a quinoxaline derivative, a pyridine derivative, a pyrimidine derivative, a phenanthrene derivative, and a naphthalene derivative. A pyrene derivative is particularly preferred because it exhibits a high emission quantum yield.Specific examples of the pyrene derivative include N,N'-Bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (1,6mMemFLPAPrn), N,N'-Bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-N,N'-diphenylpyrene-1,6-diamine (1,6FLPAPrn), N,N'-Bis(dibenzofuran-2-yl)-N,N'-diphenylpyrene-1,6-diamine (1,6FrAPrn) and N,N'-Bis(dibenzothiophene-2-yl)-N,N'-diphenylpyrene-1,6-diamine (1,6ThAPrn).

[0046] Examples of light-emitting materials that convert triplet excitation energy into light emission in the visible light range include a phosphorescent substance and a thermally activated delayed fluorescence (TADF) material. It should be noted that the TADF material is capable of up-converting a triplet excitation state to a singlet excitation state (i.e., reverse intersystem crossing is possible) using a small amount of thermal energy and efficiently emitting light (fluorescence) from the singlet excitation state. TADF is efficiently obtained under the condition that the energy difference between the triplet excitation level and the singlet excitation level is greater than or equal to 0 eV and less than or equal to 0.2 eV, preferably greater than or equal to 0 eV and less than or equal to 0.1 eV.It should be noted that the "delayed fluorescence" emitted by the TADF material refers to light emission that has the same spectrum as normal fluorescence and a very long lifetime. The lifetime is 1 × 10⁻⁶. -6 Seconds or longer, preferably 1 × 10 -3 Seconds or longer.

[0047] The phosphorescent substance can be an iridium-, rhodium-, or platinum-based organometallic complex or metal complex; in particular, an organoiridium complex, such as an iridium-based orthometallated complex, is preferred. The orthometallated ligand can be a 4H-triazole ligand, a 1H-triazole ligand, an imidazole ligand, a pyridine ligand, a pyrimidine ligand, a pyrazine ligand, an isoquinoline ligand, and the like. The metal complex can be a platinum complex with a porphyrin ligand, and the like. Examples of the phosphorescent substance include Bis[2-(3',5'-bistrifluoromethylphenyl)pyridinato-N, C 2 ']iridium(III)picolinate (abbreviation: Ir(CF3ppy)2(pic)), Bis[2-(4',6'-difluorophenyl)pyridinato-N, C 2']iridium(III)acetylacetonate (abbreviation: FIracac), Tris(2-phenylpyridinato)iridium(III) (abbreviation: Ir(ppy)3), Bis(2-phenylpyridinato)iridium(III)acetylacetonate (abbreviation: Ir(ppy)2(acac)), Tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: Tb(acac)3(Phen)), Bis(benzo[h]quinolinato)iridium(III)acetylacetonate (abbreviation: Ir(bzq)2(acac)), Bis(2,4-diphenyl-1,3-oxazolato-N,C 2 ')iridium(III)acetylacetonate (abbreviation: Ir(dpo)2(acac)), Bis{2-[4'-(perfluorophenyl)phenyl]pyridinato-N,C 2 '}iridium(III)acetylacetonate (abbreviation: Ir(p-PF-ph)2(acac)), Bis(2-phenylbenzothiazolato-N,C 2 ')iridium(III)acetylacetonate (abbreviation: Ir(bt)2(acac)), Bis[2-(2'-benzo[4,5-a]thienyl)pyridinato-N,C 3 ']iridium(III)acetylacetonate (abbreviation: Ir(btp)2(acac)), Bis(1-phenylisoquinolinato-N,C 2')iridium(III)acetylacetonate (abbreviation: Ir(piq)2(acac)), (Acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: Ir(Fdpq)2(acac)), (Acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac)]), (Acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]), (Acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: Ir(tppr)2(acac)), Bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridium(III) (abbreviation: [Ir(tppr)2(dpm)], (Acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)2(acac)]), (Acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)], 2,3,7,8,12,13,17,18-Octaethyl-21H,23H-porphyrinplatin(II) (abbreviation: PtOEP), Tris(1,3-diphenyl-1,3-propanedioneto)(monophenanthroline)europium(III) (abbreviation: Eu(DBM)3(Phen)) and Tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: Eu(TTA)3(Phen)).,

[0048] Specific examples of TADF material include fullerene, a derivative thereof, an acridine derivative such as proflavin, and eosin. Further examples include a metal-containing porphyrin, such as porphyrin containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd). Examples of the metal-containing porphyrin include a protoporphyrin-tin fluoride complex (SnF₂(Proto IX)), a mesoporphyrin-tin fluoride complex (SnF₂(Meso IX)), a hematoporphyrin-tin fluoride complex (SnF₂(Hämato IX)), a coproporphyrin-tetramethyl ester-tin fluoride complex (SnF₂(Copro III-4Me)), an octaethylporphyrin-tin fluoride complex (SnF₂(OEP)), an etioporphyrin-tin fluoride complex (SnF₂(Etio I)), and an octaethylporphyrin-platinum chloride complex (PtCl₂(OEP)). Alternatively, a heterocyclic compound with a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring can be used, such as...2-(Biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (PIC-TRZ). It should be noted that a material in which the π-electron-rich heteroaromatic ring is directly bonded to the π-electron-poor heteroaromatic ring is particularly preferred, since both the donor property of the π-electron-rich heteroaromatic ring and the acceptor property of the π-electron-poor heteroaromatic ring are increased, and the energy difference between the S1 level and the T1 level is reduced.

[0049] A light-emitting material that converts the triplet excitation energy into light emission in the visible light range is preferably used as the light-emitting substance for the other of the light-emitting layers (106a and 106b). A phosphorescent substance that emits yellow phosphorescence is preferred. With such a structure, a low-power light-emitting element can be obtained. Using such a light-emitting element as the indicator element of a light-emitting device, the power consumption required to obtain white emission can be effectively reduced.

[0050] In the case where an electron transport material is used as an organic compound for the light-emitting layers (106a and 106b), a π-electron-deficient heteroaromatic compound, such as a nitrogen-containing heteroaromatic compound, is preferred, with examples including: quinoxaline derivatives and dibenzoquinoxaline derivatives, such as... B. 2-[3-(Dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(Dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[4-(3,6-Diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(Dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II) and 6-[3-(Dibenzothiophen-4-yl)phenyl]dibenzo[F,h]quinoxaline (abbreviation: 6mDBTPDBq-II).

[0051] In the case where a hole transport material is used as an organic compound for the light-emitting layers (106a and 106b), a π-electron-rich heteroaromatic compound (e.g., a carbazole derivative or an indole derivative) or an aromatic amine compound is preferred, examples of which include: 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1), 4,4',4''-tris[N-(1-naphthyl)-N-phenylamino]triphenylamine (Abbreviation: 1'-TNATA), 2,7-Bis[N-(4-diphenylaminophenyl)-N-phenylamino]-spiro-9,9'-bifluorene (Abbreviation: DPA2SF), N,N'-Bis(9-phenylcarbazol-3-yl)-N,N'-diphenylbenzene-1,3-diamine (Abbreviation: PCA2B), N-(9,9-Dimethyl-2-diphenylamino-9H-fluoren-7-yl)diphenylamine (Abbreviation: DPNF), N,N',N''-Triphenyl-N,N',N''-tris(9-phenylcarbazol-3-yl)benzene-1,3,5-triamine (abbreviation: PCA3B), 2-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: PCASF), 2-[N-(4-diphenylaminophenyl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: DPASF), N,N'-Bis[4-(carbazol-9-yl)phenyl]-N,N'-diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviation: YGA2F), 4,4'-Bis[N-(3-methylphenyl)-N-phenylamino]biphenyl (abbreviation: TPD), 4,4'-Bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), N-(9,9-Dimethyl-9H-fluoren-2-yl)-N-{9,9-dimethyl-2-[N'-phenyl-N'-(9,9-dimethyl-9H-fluoren-2-yl)amino]-9H-fluoren-7-yl}phenylamine (abbreviation: DFLADFL), 3-[N-(9-Phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3-[N-(4-Diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA1), 3,6-Bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA2), 4,4'-Bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), 3,6-Bis[N-(4-diphenylaminophenyl)-N-(1-naphthyl)amino]-9-phenylcarbazole (abbreviation: PCzTPN2) and 3,6-Bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2).,

[0052] In the case where the light-emitting substance used for the light-emitting layer is a phosphorescent substance, examples of the organic compound used for the light-emitting layer include an aromatic amine and a carbazole derivative in addition to a zinc- or aluminum-based metal complex, an oxadiazole derivative, a triazole derivative, a benzimidazole derivative, a quinoxaline derivative, a dibenzoquinoxaline derivative, a dibenzothiophene derivative, a dibenzofuran derivative, a pyrimidine derivative, a triazine derivative, a pyridine derivative, a bipyridine derivative, and a phenanthroline derivative.

[0053] In the case where the light-emitting substance used for the light-emitting layer is a substance that emits fluorescence, an anthracene derivative or a tetracene derivative with a high S1 level and a low T1 level is preferably used. Specific examples include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (PCzPA), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7 H-dibenzo[c,g]carbazole (cgDBCzPA), 6-[3-(9,10-Diphenyl-2-anthryl)phenyl]-benzo[b]naphtho[1,2-d]furan (2mBnfPPA), 9-phenyl-10-{4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl} anthracene (FLPPA) and 5,12-diphenyltetracene and 5,12-Bis(biphenyl-2-yl)tetracene.

[0054] The electron transport layers (107a and 107b) are layers containing a substance with high electron transport properties. A metal complex can be used for the electron transport layers (107a and 107b), such as Alq3, Tris(4-methyl-8-quinolinolato)aluminum (abbreviation: Almq3), Bis(10-hydroxybenzo[h]-quinolinato)beryllium (abbreviation: BeBq2), BAlq, Zn(BOX)2, or Bis[2-(2-hydroxyphenyl)benzothiazolato]zinc(II) (abbreviation: Zn(BTZ)2). Furthermore, a heteroaromatic compound, such as...2-(4-Biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-Bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenylyl)-1,2,4-triazole (abbreviation: TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenylyl)-1,2,4-triazole (abbreviation: p-EtTAZ), bathophenanthroline (abbreviation: Bphen), bathocuproine (abbreviation: BCP) or 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs), used Alternatively, a high-molecular-weight compound such as poly(2,5-pyridindiyl) (abbreviation: PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py), or poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviation: PF-BPy) can be used. The substances listed here are mainly those with an electron mobility of 10. -6 cm 2 / Vs or higher. However, any substance other than those listed above can also be used for the electron transport layers (107a and 107b) as long as the electron transport property is higher than the hole transport property.

[0055] Each of the electron transport layers (107a and 107b) is not limited to a single layer and can be a layer arrangement of two or more layers, each containing any one of the substances listed above.

[0056] The electron injection layers (108a and 108b) are layers containing a substance with high electron injection properties. For the electron injection layers (108a and 108b), an alkali metal, an alkaline earth metal, or a compound thereof, such as lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF₂), or lithium oxide (LiO₂), can be used. x). A rare-earth metal compound, such as erbium fluoride (ErF3), can also be used. An electride can also be used for the electron injection layers (108a and 108b). Examples of the electride include a substance in which electrons are added to calcium oxide-aluminum oxide at a high concentration. Any of the substances for forming the electron transport layers (107a and 107b) mentioned above can also be used.

[0057] The electron injection layers (108a and 108b) can each be formed using a composite material in which an organic compound and an electron donor are mixed. The composite material exhibits excellent electron injection and electron transport properties, since electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material that can transport the generated electrons excellently. In particular, for example, the substances for forming the electron transport layers (107a and 107b) (e.g., a metal complex or a heteroaromatic compound) mentioned above can be used. A substance that exhibits electron-donating properties with respect to the organic compound can be used as the electron donor.In particular, an alkali metal, an alkaline earth metal, and a rare earth metal are preferred, and lithium, cesium, magnesium, calcium, erbium, ytterbium, and the like are mentioned. Furthermore, an alkali metal oxide or an alkaline earth metal oxide is preferred, and lithium oxide, calcium oxide, and barium oxide are mentioned. A Lewis base, such as magnesium oxide, may also be used. An organic compound, such as tetrathiafulvalene (abbreviation: TTF), may also be used.

[0058] In the light-emitting element described in this embodiment, the optical path length between the second electrode 102 and the light-emitting region in the EL layer 103b, which is closest to the second electrode 102, is preferably less than λ / 4, where λ is the wavelength of light emitted by the light-emitting region. For this reason, the total thickness of the electron transport layer (107b) and the electron injection layer (108b) is preferably adjusted appropriately so that the optical path length between the second electrode 102 and the light-emitting region in the EL layer 103b, which is closest to the second electrode 102, can be less than λ / 4.

[0059] The charge generation layer 109 can either have a structure in which an electron acceptor is added to a hole transport material, or a structure in which an electron donor is added to an electron transport material. Alternatively, both of these structures can be arranged on top of each other.

[0060] In the case of the structure where an electron acceptor is added to a hole transport material, an aromatic amine compound such as NPB, TPD, TDATA, MTDATA, or 4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB) can be used as the hole transport material. The substances listed here are mainly those that exhibit a hole mobility of 10 -6 cm 2exhibiting / Vs or higher. It should be noted that any substance other than those mentioned above can be used, as long as its hole transport property is higher than its electron transport property.

[0061] Examples of electron acceptors include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, and HAT-CN. Oxides of metals belonging to groups 4 to 8 of the periodic table can also be used. In particular, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide are preferred due to their high electron-accepting properties. Among these, molybdenum oxide is especially preferred because it is stable in air, has low hygroscopic properties, and is easy to handle.

[0062] In contrast, in the case of the structure where an electron donor is added to an electron transport material, a metal complex with a quinoline or benzoquinoline framework, such as Alq, Almq3, BeBq2, or BAlq, can be used as the electron transport material. Alternatively, a metal complex with an oxazole-based or thiazole-based ligand, such as Zn(BOX)2 or Zn(BTZ)2, can be used. Alternatively, in addition to such a metal complex, PBD, OXD-7, TAZ, Bphen, BCP, or the like can be used. The substances mentioned here are mainly those that exhibit an electron mobility of 10 -6 cm 2 exhibiting / Vs or higher. It should be noted that any substance other than those listed here can be used, as long as its electron transport property is higher than its hole transport property.

[0063] An alkali metal, an alkaline earth metal, a rare earth metal, a metal belonging to group 2 or 13 of the periodic table, or an oxide or carbonate thereof can be used as an electron donor. In particular, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide, cesium carbonate, or the like are preferably used. Alternatively, an organic compound, such as tetrathianaphthacene, can be used as the electron donor.

[0064] It should be noted that forming the charge generation layer 109 using one of the aforementioned materials can suppress an increase in the drive voltage caused by the layer arrangement of the EL layers.

[0065] It should be noted that each of the hole injection layers (104a and 104b), hole transport layers (105a and 105b), light emitting layers (106a and 106b), electron transport layers (107a and 107b), electron injection layers (108a and 108b) and charge generation layer 109 can be formed by a process such as an evaporation process (e.g. a vacuum evaporation process), an inkjet process or a coating process.

[0066] Although in this embodiment the light-emitting element has been described with two EL layers, a light-emitting element can also be used in which three or more EL layers are arranged on top of each other.

[0067] It should be noted that a light-emitting element, as in Fig. Figure 1B shows a single structure consisting of an EL layer. In this case, the light-emitting layer 106 comprises the first light-emitting layer 106a and the second light-emitting layer 106b. For the structures of the other components, reference can be made to the preceding description of the layers represented by the same reference symbols.

[0068] In the case of a single structure, emission efficiency can be measured using a Fig. The separate color structure shown in 27 can be improved. Even if the coloring is only performed once, the emission efficiency of a light-emitting element can be improved by the one shown in Fig. The structure shown in 27 is similar to that of a light-emitting element, in which light-emitting layers are colored separately (in the case of blue and yellow, the coloring is done twice).

[0069] A substrate 1100, first electrodes (1102B, 1102G, 1102R and 1102Y) provided above the substrate 1100, a second electrode 1104, a black matrix 1105, color filters (1106B, 1106G, 1106R and 1106Y) and a sealing substrate 1101 of the separate color structure are similar to the components in Fig. 1A and Fig. 1B. With respect to an EL layer, a hole injection and hole transport layer 1103e, a yellow light-emitting layer 1103f and an electron transport and electron injection layer 1103h can be used for all light-emitting elements, only a blue light-emitting layer 1103d is dyed separately and provided in an area where a blue light-emitting element is formed.

[0070] Here, in the yellow light-emitting layer 1103f and the blue light-emitting layer 1103d, the charge carrier equilibrium is regulated in such a way that a recombination region can be formed on the electrode side that is closer to the separately colored light-emitting layer (in this case, the blue light-emitting layer). Fig. 27. The blue-light-emitting layer 1103d is dyed separately and is located closer to the first electrode (here, the anode) than the yellow-light-emitting layer; therefore, the host materials and light-emitting materials for the blue-light-emitting layer and the yellow-light-emitting layer are selected such that the electron transport property of the blue-light-emitting layer and the yellow-light-emitting layer is each higher than their hole transport property. With such a structure, only blue light can be emitted by the light-emitting element containing the blue-light-emitting layer 1103d, and only yellow light can be emitted by the other elements, and the emission efficiency can be the same as that of an element in which a blue-light-emitting layer and a yellow-light-emitting layer are dyed separately.

[0071] The light emission mechanism of the aforementioned light-emitting element depends on the structure of the light-emitting layer and is described below using the following examples: Fig. 2, Fig. 3 and Fig. 4 described.

[0072] (1) First, two types of light emission mechanisms are described in the case where the light-emitting layer (106a or 106b) contains a light-emitting substance (a guest material 121) and a first organic compound (a host material 122) and the light-emitting substance (the guest material 121) is a substance that emits fluorescence.

[0073] It should be noted that in the light-emitting layer (106a or 106b) excitation states are formed by charge carrier recombination; the excitation states are mostly formed as excitation states of the host material 122, since the host material 122 is present in a larger quantity than the guest material 121. The ratio of the singlet excitation state to the triplet excitation state generated by charge carrier recombination (hereinafter referred to as the exciton generation probability) is approximately 1:3.

[0074] (i) If the T1 level of the host material 122 is higher than the T1 level of the guest material 121, Energy is transferred from the host material 122 in the triplet excitation state to the guest material 121 (triplet energy transfer); however, since the guest molecule is a fluorescent substance, its triplet excitation state does not emit light. Furthermore, because the guest molecule is present in a small amount in the light-emitting layer, triplet-triplet annihilation (TTA) is unlikely to occur, and therefore the triplet excitation state of the guest molecule is thermally deactivated. Consequently, a triplet exciton cannot be used for light emission; at most, approximately 25% of the injected charge carriers can be used for light emission.

[0075] (ii) If the T1 level of the host material 122 is lower than the T1 level of the guest material 121, is the correlation of energy levels of host material 122 and guest material 121 in Fig. 2 shown. The following shows what the terms and reference symbols in Fig. 2. Show: Guest: the guest material 121 (fluorescent material); Host: the host material 122; S FH : the level of the lowest singlet excitation state of the host material 122; T FH : the level of the lowest triplet excitation state of the host material 122; S FG : the level of the lowest singlet excitation state of the guest material 121 (fluorescent material); and T FG : the level of the lowest triplet excitation state of the guest material 121 (fluorescent material).

[0076] In this case, the host molecule is present in a large quantity in the light-emitting layer, so triplet-triplet annihilation (TTA) is likely to occur; therefore, some of the triplet excitons in the host material 122 are excited to the level of the lowest singlet excitation state of the host material 122 (S FH). Then energy is converted from the level of the lowest singlet excitation state of the host material 122 (S FH ) to the level of the lowest singlet excitation state of the guest material 121 (S FG ) transmitted (Route A). Consequently, the host material emits 121 light.

[0077] Since the T1 level of the host material is 122 (T FH ) is lower than the T1 level of the guest material 121 (T FG ), even in the case where charge carriers in the guest material 121 recombine directly and the triplet exciton is generated, energy from the T1 level (T FG ) to the T1 level of host material 122 (T FH ) transferred (Route B) and can be used for TTA. As a result, emission efficiency can be improved compared to the above case (i).

[0078] (2) Next, a light emission mechanism is described in the case where the light-emitting layer (106a or 106b) contains a light-emitting substance (a guest material 131), a first organic compound 132, and a second organic compound 133, and the light-emitting substance (the guest material 131) is a phosphorescent substance. It should be noted that the first organic compound 132 serves as the host material and that the weight fraction of the first organic compound 132 in the light-emitting layer is greater than that of the second organic compound 133 in the light-emitting layer.

[0079] For the light-emitting layer (106a or 106b), there is no particular restriction regarding the combination of the first organic compound 132 and the second organic compound 133, as long as they can form an exciplex (excited complex) 134; however, it is preferred that one of them be a material with hole transport properties and the other be a material with electron transport properties. In this case, a donor-acceptor excitation state is readily formed, which allows the exciplex 134 to form efficiently. In the case where the combination of the first organic compound 132 and the second organic compound 133 is a combination of the material with hole transport properties and the material with electron transport properties, the charge carrier balance can be easily controlled by regulating the mixing ratio.In particular, the ratio of the material with hole transport properties to the material with electron transport properties is preferably 1:9 to 9:1 (weight ratio). Since the charge carrier equilibrium can be easily controlled in the structure described above, the recombination range can also be easily regulated.

[0080] The correlation of energy levels of the light-emitting substance (the guest material) 131, the first organic compound 132 and the second organic compound 133 is in Fig. 3 shown. The following shows what the terms and reference symbols in Fig. 3. Show: Guest: the guest material (phosphorescent material) 131; first organic compound: the first organic compound 132; second organic compound: the second organic compound 133; Exciplex: the exciplex (excited complex) 134; S PH: the level of the lowest singlet excitation state of the first organic compound 132; T PH : the level of the lowest triplet excitation state of the first organic compound 132; T PG . the level of the lowest triplet excitation state of the guest material (phosphorescent material) 131; S E : the level of the lowest singlet excitation state of exciplex 134; and T E : the level of the lowest triplet excitation state of exciplex 134. In this case, the first organic compound 132 and the second organic compound 133 form the exciplex 134. The level of the lowest singlet excitation state of the exciplex 134 (S E ) and the level of the lowest triplet excitation state of exciplex 134 (T E They come close to each other (Route C).

[0081] It should be noted that the Exciplex 134 exists in an excited state formed by two types of substances, and this excitation is achieved through either light or electrical excitation. In the case of light excitation, the Exciplex 134 is formed when a molecule in an excited state of one substance pairs with a molecule in a ground state of the other substance. In the case of electrical excitation, there are two elementary processes by which the Exciplex is formed. One of them is the same as in the case of light excitation. The other is as follows: A cationic molecule (hole) of one substance approaches an anionic molecule (electron) of the other substance, and in this way, the Exciplex 134 is formed. At the beginning of light emission, the latter elementary process is dominant, and therefore the Exciplex 134 can be formed even if the two types of substances are not in an excited state.Therefore, the emission start voltage can be reduced, and the control voltage can also be reduced.

[0082] When the exciplex 134 is formed, energy is drawn from the level of the lowest singlet excitation state of the exciplex 134 (S E ) and the level of the lowest triplet excitation state of exciplex 134 (T E ) to the level of the lowest triplet excitation state of the guest material (phosphorescent material) 131 (T PG ) transferred (Route D); therefore, the guest material 131 emits light. It should be noted that the process in which the exciplex 134 is formed (Route C) and energy is transferred from the exciplex 134 to the guest material (phosphorescent material) 131 (Route D) is called exciplex-triplet energy transfer (ExTET).

[0083] When the Exciplex 134 returns to a ground state by losing energy, the two types of substances that formed the Exciplex 134 serve as the original distinct substances.

[0084] Depending on the combination of the first and second organic compounds that form the exciplex, the fluorescent material can emit light through an energy transfer from the exciplex to the guest material, using the fluorescent material as a host material. The fluorescent material category includes thermally activated, delayed-release fluorescent materials.

[0085] (3) Then a light emission mechanism is described in the case where one of the light-emitting layers (106a and 106b) has a multilayer structure, in which a first light-emitting layer with the light emission mechanism (TTA) described in (ii) of (1) above and a second light-emitting layer with the light emission mechanism (ExTET) described in (2) above are in contact with each other. The correlation of energy levels in this case is in Fig. 4 shown. The following shows what the terms and reference symbols in Fig. 4. Show: first light-emitting layer (fluorescence) 113: a first light-emitting layer 113; second light-emitting layer (phosphorescence) 114: a second light-emitting layer 114; S FH : the level of the lowest singlet excitation state of the host material 122; T FH: the level of the lowest triplet excitation state of the host material 122; S FG : the level of the lowest singlet excitation state of the guest material (fluorescent material) 121; T FG : the level of the lowest triplet excitation state of the guest material (fluorescent material) 121; S PH : the level of the lowest singlet excitation state of the first organic compound 132; T PH : the level of the lowest triplet excitation state of the first organic compound 132; T PG : the level of the lowest triplet excitation state of the guest material (phosphorescent material) 131; S E : the level of the lowest singlet excitation state of exciplex 134; and T E : the level of the lowest triplet excitation state of exciplex 134.

[0086] Since the exciplex 134, which is formed in the second light-emitting layer 114, exists only in one excited state, exciton diffusion between the exciplexes 134 is unlikely to occur. Furthermore, since the excitation level (S E ) of exciplex 134 is lower than both the singlet excitation level (S PH Since the singlet excitation energy of the first organic compound 132 and the singlet excitation level of the second organic compound in the second light-emitting layer 114 are both present, the singlet excitation energy does not diffuse from the exciplex 134 into the first organic compound 132 and the second organic compound. In the case where energy (in particular the triplet energy) from the exciplex 134 formed in the second light-emitting layer 114 (the level of the lowest singlet excitation state of the exciplex (S)) is present at the interface between the first light-emitting layer 113 and the second light-emitting layer 114, the singlet excitation energy of the exciplex 134 is not diffused into the first organic compound 132 and the second organic compound.E ) or the level of the lowest triplet excitation state of the exciplex (T E )) to the stimulation level (S FH , T FH When energy from the host material 122 is transferred to the first light-emitting layer 113, the singlet excitation energy is converted into light emission via a normal pathway, and the triplet excitation energy is partially converted into light emission via TTA in the first light-emitting layer 113. As a result, the energy loss can be reduced. Furthermore, exciton diffusion between the exciplexes does not occur, and therefore the energy transfer from the exciplex to the first light-emitting layer 113 occurs only at the interface.

[0087] The fact that most excitons in the second light-emitting layer 114 are in an exciplex state and exciton diffusion between the exciplexes 134 in the second light-emitting layer 114 is unlikely to occur means that the emission efficiency of the second light-emitting layer 114 can be maintained even if the T1 level of the host material 122 in the first light-emitting layer 113, which is a fluorescent layer, is lower than the T1 levels of the first organic compound 132 and the second organic compound 133 in the second light-emitting layer 114. That is to say, even if a condensed aromatic compound, such as...By using an anthracene derivative that is electrochemically stable and very reliable, but has a low triplet excitation level, efficient light emission can be obtained from the phosphorescent layer adjacent to the first light-emitting layer 113. Therefore, a characteristic of this structure is that the T1 level of the host material 122 in the first light-emitting layer 113 is lower than the T1 levels of the first organic compound 132 and the second organic compound 133 in the second light-emitting layer 114.

[0088] For the first light-emitting layer 113, it is preferred that the S1 level (not shown) of the host material 122 is higher than the S1 level of the guest material 121 and that the T1 level (T FH ) of host material 122 is lower than the T1 level (T FG) of the guest material 121. With such a structure, even in the case where energy is from the level (T E ) of the lowest triplet excitation state of the exciplex 134, which is formed in the second light-emitting layer 114, to the level (T FH The energy of the lowest triplet excitation state of the host material 122 is transferred to the first light-emitting layer 113 at the interface between the first light-emitting layer 113 and the second light-emitting layer 114. This energy is partially converted into light emission in the first light-emitting layer 113 by TTA. As a result, the energy loss can be reduced.

[0089] In the case where the aforementioned multilayer structure of light-emitting layers is used, light emitted by the first light-emitting layer 113 preferably exhibits a peak on the shorter wavelength side than light emitted by the second light-emitting layer 114. The reason for this is as follows: Since the luminance of a light-emitting element in which a phosphorescent material emitting light with a short wavelength is used tends to degrade rapidly, a light-emitting element with less luminance degradation can be provided by using a fluorescent material that emits light with a shorter wavelength than the light emitted by the second light-emitting layer 114.

[0090] In the case where the aforementioned multilayer structure of light-emitting layers is used, a third layer can be formed between the first light-emitting layer 113 and the second light-emitting layer 114, so that the first light-emitting layer 113 and the second light-emitting layer 114 are not in contact with each other. With such a structure, energy transfer (in particular triplet energy transfer) from the excited state of the first organic compound 132 or the guest material (phosphorescent material) 131, which is formed in the second light-emitting layer 114, to the host material 122 or the guest material (fluorescent material) 121 in the first light-emitting layer 113 can be prevented due to the Dexter mechanism. It should be noted that the third layer in such a structure can be formed with a thickness of several nanometers.

[0091] The third layer can be formed using a single material (a hole transport material or an electron transport material) or using both. In the case of a single material, a bipolar material can be used. Here, bipolar refers to a material where the ratio between electron mobility and hole mobility is 100 or less. The third layer can be formed using the same material as the first or second light-emitting layer. Such a structure simplifies the fabrication of the light-emitting element and reduces the drive voltage.

[0092] The light-emitting element described in this embodiment preferably has a microcavity structure. Therefore, light (monochromatic light beams) with different wavelengths can be extracted, even when the same EL layer is used. Compared to a separate color structure (where, for example, red, green, and blue are colored separately), the above structure is advantageous for a full-color display due to the ease with which higher display resolutions can be achieved. It should be noted that a combination with color layers (color filters) is also possible. The microcavity structure allows the intensity of light with a predetermined wavelength to be increased in the forward direction, thereby reducing power consumption.The above structure is particularly effective when used for backlighting or front lighting in a color display (image display device) having pixels for three or more colors; however, it can also be used for a lighting device or the like.

[0093] A light-emitting passive matrix device and a light-emitting active matrix device can be manufactured as a light-emitting device that includes the aforementioned light-emitting element.

[0094] It should be noted that there are no particular restrictions regarding the structure of the transistor (FET) used in the fabrication of the light-emitting active matrix device. For example, a staggered FET or an inverted staggered FET can be used, depending on the requirements. A driver circuit built on a FET substrate can be implemented with either an n-channel or a p-channel FET, or with either an n-channel or a p-channel FET. Furthermore, there are no particular restrictions regarding the crystallinity of a semiconductor film used for the FET. For example, both an amorphous and a crystalline semiconductor film can be used. Examples of semiconductor materials include Group 13 semiconductors (e.g., gallium), Group 14 semiconductors (e.g., silicon), compound semiconductors (including oxide semiconductors), and organic semiconductors.

[0095] Furthermore, the light-emitting element described in this embodiment can be formed on various substrates. There is no particular restriction regarding the type of substrate. Examples of substrates include a semiconductor substrate (e.g., a single-crystal substrate or a silicon substrate), an SOI substrate, a glass substrate, a quartz substrate, a plastic substrate, a metal substrate, a stainless steel substrate, a substrate comprising a stainless steel foil, a tungsten substrate, a substrate comprising a tungsten foil, a flexible substrate, a mounting film, paper containing a fiber material, and a base material film. Examples of glass substrates include a barium borosilicate glass substrate, an aluminum borosilicate glass substrate, and a soda-lime glass substrate.Examples of a flexible substrate, a mounting film, and a base material film include plastics, typically polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyethersulfone (PES); a synthetic resin of acrylic or the like; polypropylene; polyester; polyvinyl fluoride; polyvinyl chloride; polyamide; polyimide; aramid; epoxy; an evaporation-formed inorganic film; and paper.

[0096] When a transistor, along with the light-emitting element, is formed on any of these substrates, the use of a semiconductor substrate, a single-crystal substrate, an SOI substrate, or the like enables the fabrication of small transistors with minimal variation in properties, size, shape, or the like, and with high current capability. A circuit using such transistors achieves lower circuit power consumption or higher circuit integration.

[0097] If the aforementioned flexible substrate is used as the substrate over which a light-emitting element or transistor is formed, the light-emitting element or transistor can be formed directly over the flexible substrate. Alternatively, part or all of the light-emitting element or transistor can be formed over a base substrate with a separating layer provided between them, and then the light-emitting element or transistor can be separated from the base substrate and transferred to another substrate.When, as described above, the light-emitting element or transistor is transferred to another substrate using a separating layer, the light-emitting element or transistor can be formed over a substrate with low thermal resistance or a flexible substrate over which the light-emitting element or transistor is difficult to form directly. Examples of the aforementioned separating layer include a layer arrangement comprising inorganic films, such as a tungsten film and a silicon oxide film, and an organic resin film formed from polyimide or the like over a substrate.Examples of substrates onto which a transistor can be transferred include, in addition to the substrates mentioned above, a paper substrate, a cellophane substrate, an aramid film substrate, a polyimide film substrate, a stone substrate, a wood substrate, a fabric substrate (including a natural fiber (e.g., silk, cotton, or hemp), a synthetic fiber (e.g., nylon, polyurethane, or polyester), a regenerated fiber (e.g., acetate, cupro, viscose, or regenerated polyester), or the like), a leather substrate, and a rubber substrate. Using any of these substrates can increase durability or heat resistance, and reduce weight or thickness.

[0098] It should be noted that the structure described in this embodiment can be used in a suitable combination with one of the structures described in the other embodiments. (Version 2)

[0099] In this embodiment, an organic compound represented by the general formula (G1) is described in detail.

[0100] In the general formula (G1) Ar 1 and Ar 2 Each independently represents a substituted or unsubstituted aryl group with 6 to 13 carbon atoms forming a ring, and R 1 to R 8 , R 10 to R 18 and R 20 to R 28Each independently represents hydrogen, a substituted or unsubstituted alkyl group with 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 6 carbon atoms, a cyano group, a halogen, a substituted or unsubstituted haloalkyl group with 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group with 6 to 10 carbon atoms. In a substance represented by the general formula (G1), R 18 and R 28 preferably a substituted or unsubstituted phenyl group, in which case the emission wavelength of the substance may be short. The substance in which R 18 and R 28The presence of substituted or unsubstituted phenyl groups is preferably used for a light-emitting element, in which case the light-emitting element exhibits an emission spectrum with a narrow full width at half maximum (FWHM), high emission efficiency, and high reliability. To avoid deformation of a stereostructure, R 18 and R 28 more strongly favors unsubstituted phenyl groups. In the case where R 18 and R 28 Each of the phenyl groups has a substituent, the substituent is preferably an alkyl group with 1 to 6 carbon atoms or a phenyl group.

[0101] Instead of the organic compound represented by the general formula (G1), an organic compound represented by the general formula (G2) is preferably used because an emission wavelength may be shorter.

[0102] In the general formula (G2) R 1 to R 8 and R 29 to R 38 each independently represents hydrogen, a substituted or unsubstituted alkyl group with 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 6 carbon atoms, a cyano group, a halogen, a substituted or unsubstituted haloalkyl group with 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group with 6 to 10 carbon atoms.

[0103] Specific examples of the substituted or unsubstituted aryl group with 6 to 13 carbon atoms forming a ring in the general formula (G1) and the substituted or unsubstituted aryl group with 6 to 10 carbon atoms in the general formula (G2) include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, an ortho-tolyl group, a meta-tolyl group, a para-tolyl group, an ortho-biphenyl group, a meta-biphenyl group, a para-biphenyl group, a 9,9-dimethyl-9H-fluoren-2-yl group, a 9,9-diphenyl-9H-fluoren-2-yl group, a 9H-fluoren-2-yl group, a para-tert-butylphenyl group and a mesityl group.

[0104] Specific examples of the substituted or unsubstituted alkyl groups with 1 to 6 carbon atoms in the general formulas (G1) and (G2) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, a neopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, a neohexyl group, a cyclohexyl group, a 3-methylpentyl group, a 2-methylpentyl group, a 2-ethylbutyl group, a 1,2-dimethylbutyl group and a 2,3-dimethylbutyl group.

[0105] Specific examples of the substituted or unsubstituted alkoxy groups with 1 to 6 carbon atoms, the cyano group, the halogen, and the substituted or unsubstituted haloalkyl group with 1 to 6 carbon atoms in the general formulas (G1) and (G2) include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, an isobutoxy group, a tert-butoxy group, an n-pentyloxy group, an isopentyloxy group, a sec-pentyloxy group, a tert-pentyloxy group, a neopentyloxy group, an n-hexyloxy group, an isohexyloxy group, a sec-hexyloxy group, a tert-hexyloxy group, a neohexyloxy group, a cyclohexyloxy group, a 3-methylpentyloxy group, a 2-methylpentyloxy group, a 2-ethylbutoxy group, a 1,2-dimethylbutoxy group, a 2,3-dimethylbutoxy group, a cyano group, fluorine, chlorine, bromine, iodine and a trifluoromethyl group.

[0106] In this organic compound, benzonaphthofuranylamine is bonded to each of the 1-position and the 6-position of a pyrene framework, and each nitrogen atom in benzonaphthofuranylamine is independently bonded to either the 6-position or the 8-position of a benzo[b]naphtho[1,2-d]furanyl group. The structure, in which benzonaphthofuranylamine is bonded to each of the 1-position and the 6-position of the pyrene framework, allows the effective conjugation length from the pyrene framework to the benzonaphthofuranylamine to increase. Consequently, the wavelength of the emission peak can shift towards the longer wavelength side compared to the case of monocyclic pyrene. Furthermore, this structure stabilizes the molecular structure through a benzonaphthofuranyl group; therefore, an increase in reliability can be expected.Since the 6-position or the 8-position of the benzo[b]naphtho[1,2-d]furanyl group is bound to an amine skeleton, the color purity of blue can be further increased.

[0107] In the case where the 8-position of the benzo[b]naphtho[1,2-d]furanyl group is bonded to the amine backbone, light emission with a shorter wavelength can be obtained than in the case where the 6-position of the benzo[b]naphtho[1,2-d]furanyl group is bonded to the amine backbone. This is because the effective conjugation length is shorter in the case where the 8-position of the benzo[b]naphtho[1,2-d]furanyl group is bonded to the amine backbone. If the 6-position of the benzo[b]naphtho[1,2-d]furanyl group contains an aryl group and the 8-position of the benzo[b]naphtho[1,2-d]furanyl group is bonded to the amine backbone, the color purity of blue can be increased by steric hindrance of the aryl group. Furthermore, this structure can reduce intermolecular interactions, therefore high color purity can be maintained even when the concentration of the organic compound is high.

[0108] By using the aforementioned organic compound as the light-emitting substance in a light-emitting element, the drive voltage required to achieve a desired luminance can be reduced. Furthermore, a highly reliable light-emitting element can be obtained.

[0109] Specific examples of the aforementioned organic compounds (general formulas (G1) and (G2)) that can be used in a light-emitting element are shown (structural formulas (100) to (133)). It should be noted that the present invention is not limited thereto.

[0110] The aforementioned organic compound emits blue light with high color purity. A blue light emission exhibiting the chromaticity coordinates defined by the National Television Standards Committee (NTSC), i.e., (x, y) = (0.14, 0.08), or similar chromaticity coordinates, or a light emission of a deeper blue than these, can be obtained. Therefore, using such an organic compound for a light-emitting element, the drive voltage of the light-emitting element can be low, and its reliability can be high. Furthermore, using such a light-emitting element can reduce the power consumption of a light-emitting device, an electronic device, and a lighting device, which are embodiments of the present invention, and extend their service life.

[0111] It should be noted that the structure described in this embodiment can be used in a suitable combination with one of the structures described in the other embodiments. (Version 3)

[0112] This embodiment describes an embodiment of a light-emitting device in which the light-emitting element described in embodiment 1 is combined with a color layer (a color filter or the like). In this embodiment, the structure of a pixel section of the light-emitting device is determined by means of Fig. 5 described.

[0113] In Fig. In Figure 5, a plurality of FETs 502 are arranged on a substrate 501. Each of the FETs 502 is electrically connected to a light-emitting element (507R, 507G, 507B, or 507W). Specifically, each of the FETs 502 is electrically connected to a first electrode 503, which is a pixel electrode of the light-emitting element. A partition 504 is provided to cover the end sections of the adjacent first electrodes 503.

[0114] It should be noted that in this embodiment, the first electrode 503 serves as a reflective electrode. An EL layer 505 is formed over the first electrode 503, and a second electrode 510 is formed over the EL layer 505. The EL layer 505 comprises a plurality of light-emitting layers, each emitting monochromatic light. The second electrode 510 serves as a semi-transparent and semi-reflective electrode.

[0115] The light-emitting elements (507R, 507G, 507B, and 507W) emit light in different colors. Specifically, light-emitting element 507R is optically adapted to emit red light, and in an area marked 506R, red light is emitted through a color layer 508R in the direction indicated by an arrow. Light-emitting element 507G is optically adapted to emit green light, and in an area marked 506G, green light is emitted through a color layer 508G in the direction indicated by an arrow. Light-emitting element 507B is optically adapted to emit blue light, and in an area marked 506B, blue light is emitted through a color layer 508B in the direction indicated by an arrow.The light-emitting element 507W is optically adapted to emit white light, and in an area marked 506W, white light is not emitted through a color layer in the direction indicated by an arrow.

[0116] As in Fig. As shown in Figure 5, the color layers (508R, 508G, and 508B) are provided on a transparent sealing substrate 511, which is provided over the substrate 501, above which the light-emitting elements (507R, 507G, 507B, and 507W) are formed. The color layers (508R, 508G, and 508B) are provided such that they overlap the corresponding light-emitting elements (507R, 507G, and 507B), which have different emission colors.

[0117] A black layer (black matrix) 509 is provided to cover the end sections of the adjacent color layers (508R, 508G, and 508B). It should be noted that the color layers (508R, 508G, and 508B) as well as the black layer 509 may be covered with a covering layer formed using a transparent material.

[0118] The light-emitting device described above has a structure in which light is extracted from the side of the sealing substrate 511 (a top emission structure), but it can also have a structure in which light is extracted from the side of the substrate 501 on which the FETs are formed (a bottom emission structure). It should be noted that in the light-emitting device having a top emission structure as described in this embodiment, an opaque or a translucent substrate can be used as the substrate 501, whereas in a light-emitting device having a bottom emission structure, a translucent substrate must be used as the substrate 501.

[0119] One in Fig. The structure shown in Figure 10 can be used in the same way as the structure above. The structure of the light-emitting elements (507R, 507G, 507B and 507Y), which are electrically connected to the FETs 502 above the substrate 501 in Fig. The 10 connected differs in part from that in Fig. 5. A blue emission can be obtained by using the fluorescent substance described in embodiment 1 for the light-emitting layer 106a in the EL layer of embodiment 1. Furthermore, a yellow emission can be obtained from the light-emitting layer 106b in the EL layer of embodiment 1.

[0120] In this case, the light-emitting elements (507R, 507G, 507B, and 507Y) emit light of different colors. Specifically, light-emitting element 507R is optically adapted to emit red light, and in an area marked 506R, red light is emitted through the color layer 508R in the direction indicated by an arrow. Light-emitting element 507G is optically adapted to emit green light, and in an area marked 506G, green light is emitted through the color layer 508G in the direction indicated by an arrow. Light-emitting element 507B is optically adapted to emit blue light, and in an area marked 506B, blue light is emitted through the color layer 508B in the direction indicated by an arrow.The light-emitting element 507Y is optically adapted to emit yellow light, and in an area marked by 506Y, yellow light is emitted through a color layer 508Y in the direction indicated by an arrow.

[0121] As in Fig. As shown in Figure 10, the color layers (508R, 508G, 508B and 508Y) are provided on the transparent sealing substrate 511, which is provided over the substrate 501, above which the light-emitting elements (507R, 507G, 507B and 507Y) are formed. The color layers (508R, 508G, 508B and 508Y) are provided such that they overlap the corresponding light-emitting elements (507R, 507G, 507B and 507Y) which have different emission colors.

[0122] In the light-emitting device of an embodiment of the present invention, blue light emitted by the light-emitting element 507B and extracted through the color layer 508B to the outside of the light-emitting device preferably has chromaticity coordinates (x, y) of (greater than or equal to 0.13 and less than or equal to 0.17, greater than or equal to 0.03 and less than or equal to 0.08) in the xy-chromaticity diagram, so that deep blue light can be emitted. Preferably, blue light emitted by the light-emitting element 507B and extracted through the color layer 508B to the outside of the light-emitting device has a y-coordinate of greater than or equal to 0.03 and less than or equal to 0.07.

[0123] With a blue emission of such chromaticity, the luminance of the blue emission required to obtain a white emission can be reduced. Since the amount of current consumed by the blue light-emitting element to obtain a predetermined white emission is sufficiently greater than that consumed by the light-emitting elements of the other colors, the effect of reducing the current due to a decrease in the luminance of the blue emission required to obtain a white emission is enormous.

[0124] Although power efficiency is generally reduced by the desired chromaticity of blue emission, the effect of reducing the luminance of blue emission required to obtain white emission is enormous. As a result, the amount of current flowing through the blue light-emitting element to achieve a predetermined white emission is greatly reduced, and consequently, the power consumption of the entire light-emitting device is reduced.

[0125] If, as described above, the chromaticity of a blue emission corresponds to a deep blue, the color of an emission obtained by combining the blue and yellow emissions will change, and a third emission color, required to obtain a predetermined white emission, will also change in some cases. For example, furthermore, if a blue emission has chromaticity coordinates defined by NTSC, i.e., (x, y) = (0.14, 0.08), or similar chromaticity coordinates, and a yellow emission has chromaticity coordinates of (x, y) = (0.45, 0.54), or similar chromaticity coordinates, a red emission component is required to obtain a white emission with a chromaticity of approximately D65, in addition to the light emission obtained by combining the blue and yellow emissions.In contrast, if a blue emission has chromaticity coordinates defined by NTSC or similar chromaticity coordinates, and a yellow emission has chromaticity coordinates of (x, y) = (0.46, 0.53) or chromaticity coordinates of a redder emission (i.e., x is greater than 0.46 and y is less than 0.53), a white emission with a chromaticity of approximately D65 can be obtained by adding a green emission component to a light emission obtained by combining the blue and yellow emissions. However, if a yellow emission has chromaticity coordinates of a redder emission (i.e., x is greater than 0.46 and y is less than 0.53), the power efficiency of yellow pixels is reduced due to a decrease in luminance. That is, the effect of reduced power consumption is correspondingly diminished.

[0126] In this way, the third emission color required to obtain a white emission with a chromaticity of approximately D65 depends on the colors of a blue emission and a yellow emission. The power efficiency of a green emission is generally higher than that of a red emission and is therefore advantageous. However, in the case where, as described above, a yellow emission has chromaticity coordinates of a redder emission (i.e., x is greater than 0.46 and y is less than 0.53), the power efficiency of yellow pixels is reduced due to a decrease in the luminance of the yellow emission. The impact of a decrease in the power efficiency of a high-luminosity yellow emission is enormous, and therefore it is preferable that the chromaticity of a yellow emission is not close to that of a red emission.

[0127] In the case where a deep blue emission with chromaticity coordinates of (x, y) = (greater than or equal to 0.13 and less than or equal to 0.17, greater than or equal to 0.03 and less than or equal to 0.08) is used, the chromaticity of yellow with high luminosity (i.e., the chromaticity not too close to that of a red emission) is maintained, and a white emission with a chromaticity of approximately D65 can be obtained by using a green emission as a third emission, in addition to a blue emission and a yellow emission. With such a structure, the current efficiency can be kept high because a yellow emission has high luminosity. Furthermore, the luminance required for a green emission in this structure is lower than that in the case where a red emission is used as the third emission.Since the luminosity of a green emission is higher than that of a red emission, and the power efficiency of a green-emitting element is generally higher than that of a red-emitting element, the amount of current required to obtain the third emission is greatly reduced. As a result, the drive voltage is reduced, and therefore the power consumption can be lowered. The chromaticity coordinates of the yellow emission are preferably (x, y) = (greater than or equal to 0.44 and less than or equal to 0.46, greater than or equal to 0.53 and less than or equal to 0.55).

[0128] Although the luminance components of the blue light-emitting element and the light-emitting element representing the third emission for obtaining the predetermined white emission are reduced, they can be compensated for by increasing the luminance of the yellow light-emitting element. Since the luminance of the yellow emission is very high, the power efficiency of the yellow light-emitting element is also very high. An increase in power consumption due to the increase in luminance required to obtain the yellow emission can be compensated for by reducing the power consumption resulting from the decrease in luminance required for the blue light-emitting element and the light-emitting element representing the third emission. Therefore, the power consumption can be reduced.

[0129] In order to obtain a deep blue emission with chromaticity coordinates of (x, y) = (greater than or equal to 0.13 and less than or equal to 0.17, greater than or equal to 0.03 and less than or equal to 0.08), preferably (greater than or equal to 0.13 and less than or equal to 0.17, greater than or equal to 0.03 and less than or equal to 0.07) in the xy chromaticity diagram, the peak wavelength of an emission spectrum of a fluorescent material contained in a first light-emitting element is adjusted in a toluene solution of the fluorescent material to greater than or equal to 440 nm and less than or equal to 460 nm, preferably greater than or equal to 440 nm and less than or equal to 455 nm.The chromaticity of the blue light-emitting element can be regulated using a color filter or the like; however, only a small amount of light with the aforementioned wavelength can be removed by a color filter, and light emission from the fluorescent material can be used efficiently. Therefore, the full width at half maximum (FWHM) of the emission spectrum of the fluorescent material in the toluene solution is preferably greater than or equal to 20 nm and less than or equal to 50 nm.

[0130] Using a blue emission with such a chromaticity, the power consumption to obtain a white emission with chromaticity coordinates of (x, y) = (0.313, 0.329) in the xy-chromaticity diagram at approximately D65 can be reduced. In particular, in the case where a white emission with chromaticity coordinates of (x, y) = (0.313, 0.329) in the xy-chromaticity diagram is obtained at a luminance of 300 cd / m²2 The power consumption of the light-emitting device, excluding the power consumption of the driver FETs, is higher than or equal to 1 mW / cm². 2 and lower than or equal to 7 mW / cm² 2 its power consumption, which includes the power consumption of the driver FETs (the power consumption determined from the product of the current consumption and a voltage between an anode and a cathode), may be higher than or equal to 2 mW / cm² 2 and lower than or equal to 15 mW / cm² 2 be.

[0131] Using the above structure, light-emitting elements exhibiting a variety of emission colors (red, blue, green and yellow) can be provided, and furthermore, a light-emitting device suitable for emitting white light with high efficiency by combining these emission colors can be provided.

[0132] Various substrates can be used for the light-emitting device of an embodiment of the present invention. There is no particular restriction regarding the type of substrate. Examples of substrates include a semiconductor substrate (e.g., a single-crystal substrate or a silicon substrate), a SOL substrate, a glass substrate, a quartz substrate, a plastic substrate, a metal substrate, a stainless steel substrate, a substrate comprising a stainless steel foil, a tungsten substrate, a substrate comprising a tungsten foil, a flexible substrate, a mounting film, paper containing a fiber material, and a base material film. Examples of glass substrates include a barium borosilicate glass substrate, an aluminum borosilicate glass substrate, and a soda-lime glass substrate.Examples of a flexible substrate, a mounting film, and a base material film include plastics, typically polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), and polytetrafluoroethylene (PTFE); acrylic, polypropylene, polyester, polyvinyl fluoride, polyvinyl chloride, polyamide, polyimide, aramid, epoxy, an evaporation-formed inorganic film, and paper.

[0133] The use of a semiconductor substrate, a single-crystal substrate, an SOI substrate, or the like for a transistor enables the fabrication of small transistors with minimal variation in properties, size, shape, or similar characteristics, and with high current capability. A circuit using such transistors achieves lower power consumption or higher circuit integration.

[0134] A semiconductor device, such as a transistor, can be formed after a separator layer has been provided over the substrate. The separator layer can be used when part or all of the semiconductor device formed over the separator layer is separated from the substrate and transferred to another substrate. In such a case, the transistor can also be transferred to a substrate with low thermal resistance or to a flexible substrate. Examples of the aforementioned separator layer include a layer arrangement comprising inorganic films, such as a tungsten film and a silicon oxide film, and an organic resin film formed of polyimide or the like over a substrate.

[0135] In other words, once the transistor or light-emitting element has been formed using a substrate, it can be transferred to another substrate. Examples of substrates onto which the transistor or light-emitting element can be transferred include, in addition to those described above, a paper substrate, a cellophane substrate, an aramid film substrate, a polyimide film substrate, a rock substrate, a wood substrate, a fabric substrate (including a natural fiber (e.g., silk, cotton, or hemp), a synthetic fiber (e.g., nylon, polyurethane, or polyester), a regenerated fiber (e.g., acetate, cupro, viscose, or regenerated polyester), or the like), a leather substrate, and a rubber substrate.Using such a substrate allows for the creation of a transistor with excellent properties or low power consumption, the development of a device with high durability and high heat resistance, or the reduction of weight or thickness. It should be noted that in the case of manufacturing a flexible light-emitting device, a transistor or light-emitting element can be formed directly on a flexible substrate.

[0136] It should be noted that the structure described in this embodiment can be used in a suitable combination with one of the structures described in the other embodiments. (Version 4)

[0137] This embodiment describes a light-emitting device that includes a light-emitting element.

[0138] The light-emitting device can be either a passive matrix light-emitting device or an active matrix light-emitting device. It should be noted that any of the light-emitting elements described in the other embodiments can be used for the light-emitting device described in this embodiment.

[0139] In this embodiment, a light-emitting active matrix device is used based on Fig. 6A and Fig. 6B described.

[0140] It should be noted that Fig. 6A is a top view showing a light-emitting device, and Fig. 6B a cross-sectional view along the dashed-dotted line AA' in Fig. 6A. In the light-emitting active matrix device of this embodiment, a pixel section 602, a driver circuit section (a source line driver circuit) 603, and driver circuit sections (gate line driver circuits) 604a and 604b are provided above an element substrate 601. The pixel section 602, the driver circuit section 603, and the driver circuit sections 604a and 604b are sealed with a sealant 605 between the element substrate 601 and a sealing substrate 606.

[0141] Furthermore, a connection line 607 is provided above the element substrate 601 for connecting an external input terminal. Through the external input terminal, a signal (e.g., a video signal, a clock signal, a start signal, or a reset signal) or a potential is transmitted from outside to the driver circuit section 603 and the driver circuit sections 604a and 604b. A flexible printed circuit (FPC) 608 is provided here as an example of the external input terminal. Although only the FPC is shown here, the FPC can be provided with a printed circuit board (PWB). The light-emitting device in this description includes, in its category, not only the light-emitting device as such, but also the light-emitting device provided with the FPC or the PWB.

[0142] Next, a cross-sectional structure will be created based on... Fig. 6B described. The driver circuit section and the pixel section are formed above the element substrate 601; here, the driver circuit section 603, which is the source line driver circuit, and the pixel section 602 are shown.

[0143] As an example of the driver circuit section 603, a FET 609 and a FET 610 are combined. It should be noted that the driver circuit section 603 can be implemented with a circuit containing transistors of the same conduction type (either an n-channel transistor or a p-channel transistor) or with a CMOS circuit containing an n-channel transistor and a p-channel transistor. In this embodiment, the driver circuit is integrated into the substrate; however, the driver circuit is not necessarily implemented above the substrate and can be implemented outside of it.

[0144] The pixel section 602 comprises a plurality of pixels, each containing a switching FET 611, a current-controlling FET 612, and a first electrode (anode) 613 electrically connected to a line (a source electrode or a drain electrode) of the current-controlling FET 612. In this embodiment, the pixel section 602 includes two FETs, namely the switching FET 611 and the current-controlling FET 612, but is not limited to this. The pixel section 602 can, for example, include three or more FETs in combination with a capacitor.

[0145] For example, a staggered transistor or an inverted staggered transistor can be used for FETs 609, 610, 611, and 612. Examples of semiconductor materials that can be used for FETs 609, 610, 611, and 612 include Group 13 semiconductors (e.g., gallium), Group 14 semiconductors (e.g., silicon), compound semiconductors, oxide semiconductors, and organic semiconductors. Furthermore, there is no particular restriction regarding the crystallinity of the semiconductor material, and an amorphous or crystalline semiconductor can be used. In particular, an oxide semiconductor is preferably used for FETs 609, 610, 611, and 612. Examples of the oxide semiconductor include an In-Ga oxide and an In-M-Zn oxide (M being Al, Ga, Y, Zr, La, Ce, or Nd).For example, an oxide semiconductor having an energy gap of 2 eV or more, preferably 2.5 eV or more, more preferably 3 eV or more, is used for the FETs 609, 610, 611 and 612, so that the reverse current of the transistors can be reduced.

[0146] An insulator 614 is configured to cover end sections of the first electrode 613. In this embodiment, the insulator 614 is formed using a positive photosensitive acrylic resin. The first electrode 613 is used as the anode in this embodiment.

[0147] The insulator 614 preferably has a curved surface with a curvature at its upper or lower end section. This allows for advantageous coating with a film formed over the insulator 614. For example, the insulator 614 can be formed using either a negative photosensitive resin or a positive photosensitive resin. The material for the insulator 614 is not limited to an organic compound, and an inorganic compound, such as silicon dioxide, silicon oxynitride, or silicon nitride, can also be used.

[0148] An EL layer 615 and a second electrode (cathode) 616 are formed above the first electrode (anode) 613. The EL layer 615 includes at least one light-emitting layer. In addition to the light-emitting layer, the EL layer 615 may also include, as required, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a charge generation layer, and the like.

[0149] A light-emitting element 617 is formed from a layered arrangement of the first electrode (anode) 613, the EL layer 615, and the second electrode (cathode) 616. The materials described in embodiment 1 can be used for the first electrode (anode) 613, the EL layer 615, and the second electrode (cathode) 616. Although not shown, the second electrode (cathode) 616 is electrically connected to the FPC 608, which is an external input terminal.

[0150] Although the cross-sectional view in Fig. While 6B represents only a single light-emitting element 617, a plurality of light-emitting elements are arranged in a matrix within pixel section 602. Light-emitting elements providing three types of light emissions (R, G, and B) are selectively formed within pixel section 602, thereby enabling the production of a light-emitting device suitable for full-color display. In addition to the light-emitting element providing three types of light emissions (R, G, and B), for example, a light-emitting element emitting white (W), yellow (Y), magenta (M), and cyan (C) light can be formed. For example, by providing the aforementioned light-emitting element providing multiple types of light emissions, as well as a light-emitting element providing three types of light emissions (R, G, and B), high color purity, low power consumption, or similar properties can be achieved.Alternatively, a light-emitting device suitable for full-color display can be provided in combination with color filters. The light-emitting device can exhibit improved emission efficiency and reduced power consumption when combined with quantum dots.

[0151] Furthermore, the sealing substrate 606 is attached to the element substrate 601 by means of the sealing agent 605, thereby providing a light-emitting element 617 in a space 618 which is surrounded by the element substrate 601, the sealing substrate 606 and the sealing agent 605. It should be noted that the space 618 can be filled with an inert gas (such as nitrogen or argon) or with the sealing agent 605.

[0152] An epoxy-based resin or a glass frit is preferably used for the sealant 605. Preferably, the material is as impermeable as possible to moisture and oxygen. The sealant substrate 606 can be any of the materials described in embodiment 3, such as a glass substrate, a quartz substrate, or a plastic substrate made of fiber-reinforced plastic (FRP), polyvinyl fluoride (PVF), polyester, acrylic, or the like. In the case where a glass frit is used as the sealant, the element substrate 601 and the sealant substrate 606 are preferably glass substrates for high adhesion.

[0153] A light-emitting active matrix device can be obtained in the manner described above.

[0154] It should be noted that the structure described in this embodiment can be used in a suitable combination with one of the structures described in the other embodiments. (Version 5)

[0155] In this embodiment, examples of various electronic devices manufactured using a light-emitting device are shown by means of Fig. 7A, Fig. 7B, Fig. 7C, Fig. 7D, Fig. 7D'-1 and Fig. 7D'-2 described.

[0156] Examples of electronic devices that incorporate the light-emitting device include television sets (also called TVs or television receivers), computer monitors and the like, cameras such as digital cameras and digital video cameras, digital photo frames, mobile phones (also called cell phones or mobile phone devices), portable game consoles, portable information terminals, audio playback devices, and large gaming machines such as pachinko machines. Specific examples of the electronic devices are in Fig. 7A, Fig. 7B, Fig. 7C, Fig. 7D, Fig. 7D'-1 and Fig. 7D'-2 is shown.

[0157] Fig. Figure 7A represents an example of a television set. In the television set 7100, a display section 7103 is installed in a housing 7101. The display section 7103 can display images and can be a touchscreen (an input-output device) that includes a touch sensor (an input device). It should be noted that the light-emitting device, which is an embodiment of the present invention, can be used for the display section 7103. In addition, the housing 7101 is supported by a base 7105.

[0158] The television set 7100 can be operated using the power switch on the housing 7101 or using a separate remote control 7110. The remote control 7110's control buttons 7109 allow the selection of television channels and the volume to be adjusted, and images displayed on the screen 7103 can be controlled. Furthermore, the remote control 7110 can be equipped with a display 7107 to show data output by the remote control 7110.

[0159] It should be noted that the 7100 television set is equipped with a receiver, a modem, and the like. Using the receiver, general television broadcasts can be received. Furthermore, when the television set is connected to a communication network via modem, either wirelessly or via cable, unidirectional (from a sender to a receiver) or bidirectional (between a sender and a receiver or between receivers) information communication can take place.

[0160] Fig. Figure 7B represents a computer comprising a main body 7201, a housing 7202, a display section 7203, a keyboard 7204, an external connection port 7205, a pointing device 7206, and the like. It should be noted that this computer can be manufactured by using the light-emitting device, which is an embodiment of the present invention, for the display section 7203. The display section 7203 can be a touchscreen (an input-output device) that includes a touch sensor (an input device).

[0161] Fig. 7C represents a smartwatch comprising a case 7302, a display panel 7304, control buttons 7311 and 7312, a connection port 7313, a band 7321, a clasp 7322 and the like.

[0162] The display panel 7304, mounted in the housing 7302 which serves as a frame, has a non-rectangular display area. The display panel 7304 can display an icon 7305, which shows the time, another icon 7306, and the like. The display panel 7304 can be a touchscreen (an input / output device) that includes a touch sensor (an input device).

[0163] The in Fig. The smartwatch shown in Figure 7C can have various functions, such as a function to display different information (e.g., a still image, a moving image, and a text image) on a display section, a touchscreen function, a function to display a calendar, date, time, and the like, a function to control processing using various software (programs), a wireless communication function, a function to connect to different computer networks using a wireless communication function, a function to send and receive various data using a wireless communication function, and a function to read a program or data stored in a storage medium and to display the program or data on a display section.

[0164] The 7302 housing can contain a speaker, a sensor (a sensor with a function for measuring force, displacement, position, speed, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, electrical power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays), a microphone, and the like. It should be noted that the smartwatch can be manufactured using the 7304 light-emitting device for the display panel.

[0165] Fig. Figure 7D represents an example of a mobile phone (e.g., a smartphone). A mobile phone 7400 includes a housing 7401, which is provided with a display section 7402, a microphone 7406, a speaker 7405, a camera 7407, an external connection section 7404, an operating button 7403, and the like. In the case where a light-emitting device is produced by forming a light-emitting element over a flexible substrate, as in Fig. 7D shown, the light-emitting element for the display section 7402 is used with a curved surface.

[0166] If the display section 7402 of the mobile phone 7400, which is in Fig. When the display section 7402, shown in 7D, is touched with a finger or similar object, data can be entered into the 7400 mobile phone. Furthermore, actions such as making a call and composing an email can be performed by touching the display section 7402 with a finger or similar object.

[0167] There are three main screen modes for the 7402 display section. The first mode is a display mode, primarily for showing images. The second mode is an input mode, primarily for entering data, such as text. The third mode is a combined display and input mode.

[0168] For example, when making a call or composing an email, a text input mode primarily used for entering characters is selected for display section 7402, allowing the input of characters shown on the screen. In this case, it is preferred that a keyboard or number keys be displayed across almost the entire screen of display section 7402.

[0169] If a detector device, such as a gyroscope or an accelerometer, is provided in the 7400 mobile phone, the display on the screen of the 7402 display section can be automatically switched by determining the orientation of the 7400 mobile phone (depending on whether the mobile phone is positioned horizontally or vertically).

[0170] The screen modes are switched by touching the display section 7402 or by using the button 7403 on the housing 7401. The screen modes can also be switched depending on the type of image displayed on the display section 7402. For example, if the signal from an image displayed on the display section is data from moving images, the screen mode switches to display mode. If the signal is data from text, the screen mode switches to input mode.

[0171] Furthermore, if no input is made by touching the display section 7402 for a certain period of time in input mode, while a signal detected by an optical sensor in the display section 7402 is being detected, the screen mode can be controlled such that it switches from input mode to display mode.

[0172] The display section 7402 can serve as an image sensor. For example, an image of a handprint, fingerprint, or the like can be captured by touching the display section 7402 with the palm or finger, thus enabling personal authentication. Furthermore, if a backlight or a scanning light source emitting near-infrared light is provided in the display section, an image of a finger vein, palm vein, or the like can be captured.

[0173] The light-emitting device can also be used for a mobile phone that has a structure located in Fig. 7D'-1 or Fig. 7D'-2 is shown, which is another structure of the mobile phone (e.g. smartphones).

[0174] It should be noted that in the case of the structure which is in Fig. 7D'-1 or Fig. As depicted in 7D'-2, text data, image data, or the like can be displayed on secondary screens 7502(1) and 7502(2) of housings 7500(1) and 7500(2), as well as on primary screens 7501(1) and 7501(2). Such a structure allows a user to easily view text data, image data, or the like displayed on the secondary screens 7502(1) and 7502(2) while the mobile phone is placed in the user's breast pocket.

[0175] Fig. 8A to Fig. 8C represents a foldable, portable information terminal 9310. Fig. Figure 8A represents the portable information terminal 9310, which is unfolded. Fig. 8B represents the portable information terminal 9310, which can be opened or closed. Fig. Figure 8C depicts the 9310 portable information terminal in its folded position. The 9310 portable information terminal is highly portable when folded. When unfolded, the 9310 portable information terminal offers a large, seamless display area that is highly searchable.

[0176] A display panel 9311 is supported by three housings 9315 connected to each other by hinges 9313. It should be noted that the display panel 9311 can be a touchscreen (an input / output device) that includes a touch sensor (an input device). The portable information terminal 9310 can be reversibly changed in shape from an open to a closed state by bending the display panel 9311 at a connection point between two housings 9315 using the hinges 9313. A light-emitting device of an embodiment of the present invention can be used for the display panel 9311. A display area 9312 in the display panel 9311 is a display area that is positioned on a side face of the closed portable information terminal 9310.The display area 9312 can show information icons, frequently used applications, program shortcuts and the like, and confirmation of information and starting of applications can be carried out without any problems.

[0177] As described above, the electronic devices can be obtained using the light-emitting device of an embodiment of the present invention. It should be noted that the light-emitting device for electronic devices can be used in various fields, without being limited to the electronic devices described in this embodiment. (Version 6)

[0178] In this embodiment, examples of lighting devices are given based on Fig. 9 described. The lighting devices each include a light-emitting device.

[0179] Fig. Figure 9 presents an example in which the light-emitting device is used as an interior lighting device 8001. Since the light-emitting device can have a large surface area, it can be used for a lighting device that covers a large area. Furthermore, by using a housing with a curved surface, a lighting device 8002 can be obtained, which includes the housing, a cover, or a support and in which a light-emitting area has a curved surface. A light-emitting element contained in the light-emitting device described in this embodiment is in the form of a thin film, which allows for greater freedom in the design of the housing. Consequently, the lighting device can be artistically designed in various ways. In addition, a wall of the room can be provided with a large lighting device 8003.

[0180] If the light-emitting device is used for the surface of a table, a lighting device 8004 with a function as a table can be obtained. If the light-emitting device is used as part of another piece of furniture, a lighting device serving as that piece of furniture can be obtained.

[0181] In this way, various lighting devices can be obtained that include the light-emitting device. It should be noted that these lighting devices are also embodiments of the present invention.

[0182] It should be noted that the structure described in this embodiment can be used in a suitable combination with one of the structures described in the other embodiments. (Version 7)

[0183] In this embodiment, a touchscreen incorporating a light-emitting element or device is used, based on Fig. 11A and Fig. 11 B, Fig. 12A and Fig. 12B, Fig. 13A and Fig. 13B, Fig. 14A and Fig. 14B as well Fig. 15 described.

[0184] Fig. 11A and Fig. Figure 11B shows perspective views of a Touchscreen 2000. It should be noted that Fig. 11A and Fig. For the sake of simplicity, section 11B only shows typical components of the Touchscreen 2000.

[0185] The touchscreen 2000 includes a display section 2501 and a touch sensor 2595 (see Fig. 11B). Furthermore, the Touchscreen 2000 includes a Substrate 2510, a Substrate 2570, and a Substrate 2590. It should be noted that the Substrate 2510, the Substrate 2570, and the Substrate 2590 each exhibit flexibility.

[0186] The display section 2501 includes a plurality of pixels above the substrate 2510 and a plurality of lines 2511 through which signals are supplied to the pixels. The plurality of lines 2511 extends to a peripheral section of the substrate 2510, and part of the plurality of lines 2511 forms a terminal 2519. The terminal 2519 is electrically connected to an FPC 2509(1).

[0187] The substrate 2590 includes the touch sensor 2595 and a plurality of conductors 2598 that are electrically connected to the touch sensor 2595. The plurality of conductors 2598 extends to a peripheral section of the substrate 2590, and part of the plurality of conductors 2598 forms a connection layer 2599. The connection layer 2599 is electrically connected to an FPC 2509(2). It should be noted that in Fig. 11B Electrodes, leads and the like of the touch sensor 2595, which are provided on the back of the substrate 2590, are shown by solid lines for clarity.

[0188] For example, a capacitive touch sensor can be used as the touch sensor 2595. Examples of capacitive touch sensors include surface capacitive touch sensors and projected capacitive touch sensors.

[0189] Examples of projected capacitive touch sensors include self-capacitive touch sensors and mutual capacitive touch sensors, which differ primarily in their control method. A mutual capacitive touch sensor is preferably used because it allows for the simultaneous detection of multiple points.

[0190] An example of the use of a projected capacitive touch sensor will first be given using the following: Fig. 11B described below. It should be noted that in the case of a projected capacitive touch sensor, various sensors capable of detecting the proximity or contact of a detection object, such as a finger, may be used.

[0191] The projected capacitive touch sensor 2595 includes electrodes 2591 and electrodes 2592. The electrodes 2591 are electrically connected to any one of the plurality of leads 2598, and the electrodes 2592 are electrically connected to any one of the other leads 2598. The electrodes 2592 each have the shape of a plurality of quadrilaterals arranged in one direction, with one corner of one quadrilateral being connected to a corner of another quadrilateral by a lead 2594 in one direction, as shown in Fig. 11A and Fig. Figure 11B shows that the electrodes 2591 each have the same shape of a plurality of quadrilaterals arranged in one direction, with one corner of one quadrilateral connected to a corner of another quadrilateral; however, the direction in which the electrodes 2591 are connected is a direction that intersects the direction in which the electrodes 2592 are connected. It should be noted that the direction in which the electrodes 2591 are connected and the direction in which the electrodes 2592 are connected are not necessarily perpendicular to each other, and the electrodes 2591 may be arranged such that they intersect with the electrodes 2592 at an angle greater than 0° and less than 90°.

[0192] The intersection area of ​​the conductor 2594 and one of the electrodes 2592 is preferably as small as possible. Such a structure allows for a reduction in the area where the electrodes are not present, thus reducing any unevenness in transmittance. This, in turn, reduces the unevenness of the luminance of light emitted by the touch sensor 2595.

[0193] It should be noted that the shapes of the electrodes 2591 and the electrodes 2592 are not limited to those described above and can have any number of different shapes. For example, the plurality of electrodes 2591 can be provided such that the distance between the electrodes 2591 is minimized, and a plurality of electrodes 2592 can be provided with an insulating layer between the electrodes 2591 and the electrodes 2592. In this case, it is preferred that a dummy electrode be provided between two adjacent electrodes 2592, which is electrically insulated from these electrodes, thereby reducing the area of ​​a region exhibiting differential permeability.

[0194] Next, the Touchscreen 2000 will be described in detail using the following examples: Fig. 12A and Fig. 12B described. Fig. 12A is a cross-sectional view along the dashed-dotted line X1-X2 in Fig. 11A.

[0195] The touch sensor 2595 includes the electrodes 2591 and the electrodes 2592, which are arranged in an offset arrangement on the substrate 2590, an insulating layer 2593 that covers the electrodes 2591 and the electrodes 2592, and the conductor 2594 that electrically connects the adjacent electrodes 2591.

[0196] An adhesive layer 2597 is provided below the conductor 2594. The adhesive layer 2597 attaches the substrate 2590 to the substrate 2570, so that the touch sensor 2595 overlaps with the display section 2501.

[0197] Electrodes 2591 and 2592 are formed using a translucent conductive material. A conductive oxide, such as indium oxide, indium tin oxide, iridium zinc oxide, zinc oxide, or zinc oxide to which gallium has been added, can be used as the translucent conductive material. It should be noted that a graphene-containing film can also be used. The graphene-containing film can be formed, for example, by reducing a graphene oxide-containing film. A heat-supplying process or the like can be used as the reduction method.

[0198] The electrodes 2591 and the electrodes 2592 can be formed, for example, by depositing a translucent conductive material onto the substrate 2590 by a sputtering process and then removing an unnecessary section by any of several structuring techniques, such as photolithography.

[0199] Examples of insulating layer material 2593 include a resin, such as an acrylic or epoxy resin, a resin with a siloxane bond, and an inorganic insulating material, such as silicon dioxide, silicon oxynitride, or aluminum oxide.

[0200] The conductor 2594 is formed in an opening provided in the insulating layer 2593, thereby electrically connecting the adjacent electrodes 2591. A translucent conductive material can be advantageously used for the conductor 2594, as this increases the open-field ratio of the touchscreen. Furthermore, a material with a higher conductivity than electrodes 2591 and 2592 can be advantageously used for the conductor 2594, as this reduces the electrical resistance.

[0201] A pair of electrodes 2591 are electrically connected via line 2594. Electrode 2592 is provided between the pair of electrodes 2591.

[0202] A conductor 2598 is electrically connected to one of the electrodes 2591 and 2592. A portion of the conductor 2598 serves as a terminal. The conductor 2598 can be made of a metallic material such as aluminum, gold, platinum, silver, nickel, titanium, tungsten, chromium, molybdenum, iron, cobalt, copper, or palladium, or an alloy containing any of these metallic materials.

[0203] The conductor 2598 and the FPC 2509(2) are electrically connected via the junction layer 2599. The junction layer 2599 can be formed using any of the various anisotropic conductive films (ACF), anisotropic conductive pastes (ACP), and the like.

[0204] The adhesive layer 2597 is translucent. For example, a thermosetting resin or a UV-curing resin can be used; in particular, a resin such as an acrylic-based resin, a urethane-based resin, an epoxy-based resin, or a siloxane-based resin can be used.

[0205] The display section 2501 contains a large number of pixels arranged in a matrix. Each pixel contains a display element and a pixel circuit for controlling the display element.

[0206] For substrate 2510 and substrate 2570, for example, a flexible material with a water vapor permeability of 1 × 10 can be used. -5 g / (m 2 (day) or less, preferably 1 × 10 -6 g / (m 2·day) or less, are advantageously used. It should be noted that materials whose coefficients of thermal expansion are essentially the same are preferably used for substrate 2510 and substrate 2570. For example, the coefficients of linear expansion of the materials are preferably less than or equal to 1 × 10 -3 / K, more strongly preferred, less than or equal to 5 × 10 -5 / K, even more strongly preferred to be lower than or equal to 1 × 10 -5 / K.

[0207] A sealing layer 2560 preferably has a higher refractive index than air.

[0208] The display section 2501 contains a pixel 2502R. The pixel 2502R contains a light-emitting module 2580R.

[0209] The 2502R pixel contains a 2550R light-emitting element and a 2502t transistor, which supplies electrical energy to the 2550R light-emitting element. It should be noted that the 2502t transistor serves as part of the pixel circuit. The 2580R light-emitting module contains the 2550R light-emitting element and a 2567R color layer.

[0210] The light-emitting element 2550R includes a lower electrode, an upper electrode, and an EL layer between the lower electrode and the upper electrode.

[0211] In the case where the sealing layer 2560 is provided on the light extraction side, the sealing layer 2560 is in contact with the light emitting element 2550R and the color layer 2567R.

[0212] The color layer 2567R overlaps with the light-emitting element 2550R. Consequently, some of the light emitted by the light-emitting element 2550R passes through the color layer 2567R and is emitted to the outside of the light-emitting module 2580R, like an arrow in Fig. 12A is shown.

[0213] The display section 2501 includes an opaque layer 2567BM on the light extraction side. The opaque layer 2567BM is arranged such that it surrounds the color layer 2567R.

[0214] The display section 2501 includes an antireflection layer 2567p in an area that overlaps with pixels. For example, a circularly polarizing plate can be used as the antireflection layer 2567p.

[0215] An insulating layer 2521 is provided in the display section 2501. The insulating layer 2521 covers the transistor 2502t. The insulating layer 2521 reduces an unevenness caused by the pixel circuit. The insulating layer 2521 can also serve as a layer to prevent the diffusion of impurities. This can prevent the reliability of the transistor 2502t or similar components from being degraded as a result of impurity diffusion.

[0216] The light-emitting element 2550R is formed above the insulating layer 2521. A partition 2528 is provided such that it covers end sections of the lower electrode of the light-emitting element 2550R. It should be noted that a spacer for controlling the distance between the substrate 2510 and the substrate 2570 may be provided above the partition 2528.

[0217] A sampling line driver circuit 2503g(1) includes a transistor 2503t and a capacitor 2503c. It should be noted that the driver circuit and the pixel circuits can be formed in the same process on the same substrate.

[0218] Above substrate 2510 are lines 2511, through which a signal can be supplied. Connection 2519 is provided above lines 2511. The FPC 2509(1) is electrically connected to connection 2519. The FPC 2509(1) has a function for supplying signals, such as a pixel signal and a synchronization signal. It should be noted that a printed circuit board (PWB) can be attached to the FPC 2509(1).

[0219] The display section 2501 can use transistors with different structures. In the example of Fig. A bottom-gate transistor is used in the 12A circuit. This applies to both transistors 2502t and 2503t, which are located in... Fig. As shown in Figure 12A, a semiconductor layer containing an oxide semiconductor can be used for one channel region. Alternatively, in each of transistors 2502t and 2503t, a semiconductor layer containing amorphous silicon can be used for one channel region. Alternatively, in each of transistors 2502t and 2503t, a semiconductor layer containing polycrystalline silicon, obtained by a crystallization process such as laser annealing, can be used for one channel region.

[0220] Fig. Figure 12B shows the structure of the display section 2501, which uses a top-gate transistor.

[0221] In the case of a top-gate transistor, in addition to the aforementioned semiconductor layers that can be used for a bottom-gate transistor, a semiconductor layer containing polycrystalline silicon, a single-crystal silicon film transferred from a single-crystal silicon substrate, or the like can be used for a channel area.

[0222] Next, a touchscreen with a structure that differs from the one in Fig. 12A and Fig. As shown in 12B, it differs based on Fig. 13A and Fig. 13B described.

[0223] Fig. 13A and Fig. Figure 13B shows cross-sectional views of a 2001 touchscreen. The 2001 touchscreen, which is in Fig. 13A and Fig. As shown in Figure 13B, the relative position of the touch sensor 2595 with respect to the display section 2501 differs from that of the touchscreen 2000, which is shown in Fig. 12A and Fig. Figure 12B is shown. Only different structures are described in detail below, and for other, similar structures, reference can be made to the preceding description of the Touchscreen 2000.

[0224] The color layer 2567R overlaps with the light-emitting element 2550R. The light-emitting element 2550R, which is in Fig. As shown in Figure 13A, light is emitted towards the side where transistor 2502t is located. Therefore, some of the light emitted by light-emitting element 2550R passes through the color layer 2567R and is emitted towards the outside of light-emitting module 2580R, as indicated by an arrow in Figure 13A. Fig. 13A is shown.

[0225] The display section 2501 includes the opaque layer 2567BM on the light extraction side. The opaque layer 2567BM is arranged such that it surrounds the color layer 2567R.

[0226] The touch sensor 2595 is provided on the side of the substrate 2510 of the display section 2501 (see Fig. 13A).

[0227] The display section 2501 and the touch sensor 2595 are attached to each other using the adhesive layer 2597, which is provided between the substrate 2510 and the substrate 2590.

[0228] The display section 2501 can use transistors with different structures. In the example of Fig. A bottom-gate transistor is used in 13A. In the example of Fig. A top-gate transistor is used in 13B.

[0229] Then an example of a touchscreen control method will be given using... Fig. 14A and Fig. 14B described.

[0230] Fig. Figure 14A is a block diagram illustrating the structure of a mutual capacitive touch sensor. Fig. 14A represents a pulse voltage output circuit 2601 and a current sensing circuit 2602. It should be noted that in the example of Fig. 14A represents six leads X1 to X6 electrodes 2621 to which a pulse voltage is supplied, and six leads Y1 to Y6 electrodes 2622 that detect the changes in current. Fig. 14A also represents a capacitor 2603, which is formed in a region where electrodes 2621 and 2622 overlap. It should be noted that a functional exchange between electrodes 2621 and 2622 is possible.

[0231] The pulse voltage output circuit 2601 is a circuit for sequentially applying a pulse voltage to lines X1 to X6. Applying a pulse voltage to lines X1 to X6 generates an electric field between electrodes 2621 and 2622 of capacitor 2603. When the electric field between the electrodes is blocked, a change (in capacitance) occurs in capacitor 2603. This change can be used to detect the approach or contact of a sensor object.

[0232] The current sensing circuit 2602 is a circuit for detecting changes in the current flowing through lines Y1 to Y6, which are caused by changes in the capacitance of the capacitor 2603. No change in the current value is detected on lines Y1 to Y6 when there is no approach to or contact with a sensing object, while a decrease in the current value is detected when the capacitance decreases due to approach to or contact with a sensing object. It should be noted that an integrator circuit or similar is used to detect the current values.

[0233] Fig. 14B is a flowchart showing the input and output waveforms of the [unclear text] in Fig. Figure 14A shows the mutually capacitive touch sensor. Fig. In 14B, a capture object is performed in all rows and columns within one frame period. Fig. Figure 14B shows a period in which no object is detected (no contact) and a period in which an object is detected (contact). The detected current values ​​of lines Y1 to Y6 are shown as waveforms of the voltage values.

[0234] A pulse voltage is sequentially applied to lines X1 to X6, and the waveforms of lines Y1 to Y6 change according to the pulse voltage. If there is no approach to or contact with a detection object, the waveforms of lines Y1 to Y6 change according to changes in the voltages of lines X1 to X6. The current value decreases at the point where approach to or contact with a detection object occurs, and the waveform of the voltage value changes accordingly. By detecting a change in capacitance in this way, the approach to or contact with a detection object can be detected.

[0235] Although Fig. Figure 14A shows a passive touch sensor where only the capacitor 2603 is provided as a touch sensor at the intersection of the lines, but an active touch sensor can also be used which includes a transistor and a capacitor. Fig. Figure 15 shows a sensor circuit that is included in an active touch sensor.

[0236] The sensor circuit, which is in Fig. Figure 15 shows the capacitor 2603, a transistor 2611, a transistor 2612 and a transistor 2613.

[0237] A signal G2 is input to a gate of transistor 2613. A voltage VRES is applied to a source or drain of transistor 2613, and one electrode of capacitor 2603 and one gate of transistor 2611 are electrically connected to each other via the source and drain of transistor 2613. A source or drain of transistor 2611 is electrically connected to a source or drain of transistor 2612, and a voltage VSS is applied to each of these points via the source and drain of transistor 2611. A signal G1 is input to a gate of transistor 2612, and a line ML is electrically connected to each of these points via the source and drain of transistor 2612. The voltage VSS is applied to the other electrode of capacitor 2603.

[0238] Next, the operating principle of the sensor circuit, which is located in Fig. As shown in Figure 15, the process is described. First, a potential to turn on transistor 2613 is applied as signal G2, and a potential relative to the voltage VRES is thus applied to node n, which is connected to the gate of transistor 2611. Then, a potential to turn off transistor 2613 is applied as signal G2, thereby maintaining the potential of node n. Next, the capacitance of capacitor 2603 changes as a result of approaching or contacting a sensing object, such as a finger, and accordingly, the potential of node n is changed relative to VRES.

[0239] During a reading operation, a potential is applied to switch on transistor 2612 as signal G1. Corresponding to the potential of node n, a current flows through transistor 2611, i.e., a current flows through line ML. By detecting this current, the approach to or contact with a detection object can be detected.

[0240] In each of the transistors 2611, 2612, and 2613, an oxide semiconductor layer is preferably used as the semiconductor layer in which a channel region is formed. In particular, such a transistor is preferably used for transistor 2613, so that the potential of node n can be maintained for a long time and the frequency of an operation to re-supply VRES to node n (update operation) can be reduced.

[0241] At least part of this embodiment may optionally be implemented in combination with one of the embodiments described in this description. [Example 1]

[0242] This example describes the results of calculating the power consumption of light-emitting devices that produce a white display. The light-emitting device of the present invention uses light-emitting elements (a yellow light-emitting element: light-emitting element 1, a blue light-emitting element: light-emitting element 2, and a green light-emitting element: light-emitting element 3). The light-emitting device of a comparative example uses light-emitting elements (a yellow light-emitting element: comparison element 1, a blue light-emitting element: comparison element 2, and a red light-emitting element: comparison element 3).

[0243] The reason why light-emitting elements 1 to 3 are light-emitting elements that emit yellow light, blue light, and green light, respectively, and the light-emitting comparison elements 1 to 3 are light-emitting elements that emit yellow light, blue light, and red light, respectively, is that light of such colors is required to obtain white light with a chromaticity of approximately D65 (light with chromaticity coordinates of (x, y) = (0.313, 0.329) in the xy-chromaticity diagram). It should be noted that in the light-emitting device of this example, no red light is required to obtain white light, and that in the light-emitting device of the comparison example, no green light is required to obtain white light; therefore, a description of these is omitted.

[0244] Structural formulas of organic compounds used in light-emitting elements 1 to 3 and light-emitting reference elements 1 to 3 are shown below. (Method for producing the light-emitting elements 1 to 3 and the light-emitting comparison elements 1 to 3)

[0245] First, an alloy film of silver (Ag), palladium (Pd), and copper (Cu) (hereinafter referred to as APC) was formed over a glass substrate by a sputtering process to create a first electrode (reflective electrode). The thickness of the first electrode was 100 nm, and the electrode area was 2 mm × 2 mm.

[0246] Subsequently, a transparent conductive film of indium tin oxide containing silicon oxide was formed over the first electrode by a sputtering process. The thickness of the transparent conductive film of light-emitting element 1 was 30 nm, that of light-emitting element 2 was 80 nm, and that of light-emitting element 3 was 30 nm. The thickness of the transparent conductive film of light-emitting reference element 1 was 30 nm, that of light-emitting reference element 2 was 60 nm, and that of light-emitting reference element 3 was 60 nm.

[0247] Then, as a pretreatment for the evaporation of an organic compound layer, a surface of the substrate, which was equipped with the reflective electrode and the transparent conductive film, was washed with water, baking was carried out for one hour at 200 °C, and then a UV ozone treatment was carried out for 370 seconds.

[0248] The substrate was then transferred to a vacuum evaporation device, in which the pressure was increased to approximately 10 -4 The Pa had been reduced and was heated for 30 minutes in a vacuum at 170 °C in a heating chamber of the vacuum evaporation device, and then the substrate was cooled for about 30 minutes.

[0249] The substrate was then attached to a substrate holder in the vacuum evaporation apparatus such that the surface on which the transparent conductive film had formed faced downwards. The pressure in the vacuum evaporation apparatus was set to approximately 10-4 Pa reduced. Subsequently, 3-[4-(9-Phenanthryl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPPn), which is represented by the structural formula (i), and molybdenum(VI) oxide were deposited on the transparent conductive film by co-evaporation, using resistance heating, thereby forming a first hole injection layer. The thickness of the first hole-injected layer of light-emitting element 1 was 60 nm, that of light-emitting element 2 was 47.5 nm, and that of light-emitting element 3 was 40 nm. The thickness of the first hole-injected layer of light-emitting reference element 1 was 55 nm, that of light-emitting reference element 2 was 70 nm, and that of light-emitting reference element 3 was 45 nm. The weight ratio of PCPPn to molybdenum oxide was set to 1:0.5.

[0250] Subsequently, PCPPn was deposited on the first hole injection layer in a thickness of 10 nm, thereby forming a first hole transport layer.

[0251] For each of the light-emitting elements 1 to 3, a first light-emitting layer was formed on the first hole transport layer by deposition of 7-[4-(10-Phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), which is represented by structural formula (ii), and N,N'-(Pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), which is represented by structural formula (iii), in a thickness of 25 nm, so that the weight ratio of cgDBCzPA to 1,6BnfAPrn-03 was 1:0.05.

[0252] For each of the light-emitting reference elements 1 to 3, a first light-emitting layer was formed on the first hole transport layer by deposition of cgDBCzPA and N,N'-Bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]-pyren-1,6-diamine (abbreviation: 1,6mMemFLPARN), which is represented by the structural formula (x), in a thickness of 25 nm, so that the weight ratio of cgDBCzPA to 1,6mMemFLPARN was 1:0.05.

[0253] Then, a first electron transport layer was formed over the first light-emitting layer in such a way that cgDBCzPA was deposited at a thickness of 5 nm and bathophenanthroline (abbreviation: BPhen), which is represented by the structural formula (iv), was deposited at a thickness of 15 nm.

[0254] After the first electron transport layer had formed, lithium oxide (Li₂O) was deposited by evaporation to a thickness of 0.1 nm. Then, copper phthalocyanine (abbreviation: CuPc), represented by structural formula (xi), was deposited by evaporation to a thickness of 2 nm. Subsequently, 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT₃P-II), represented by structural formula (v), and molybdenum(VI) oxide were deposited by co-evaporation, resulting in a weight ratio of DBT₃P-II to molybdenum oxide of 1:0.5. This formed an intermediate layer with a thickness of 12.5 nm.

[0255] Subsequently, 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), which is represented by the structural formula (vi), was deposited on the intermediate layer by evaporation to a thickness of 20 nm, thereby forming a second hole transport layer.

[0256] After the second hole transport layer had formed, 2-[3'-(Dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), which is represented by structural formula (vii), N-(1,1'-Biphenyl-4-yl)-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluorene-2-amine (abbreviation: PCBBiF), which is represented by structural formula (viii), and Bis{2-[5-methyl-6-(2-methylphenyl)-4-pyrimidinyl-κN3]phenyl-κC}(2,4-pentanedionato-κ 2 Iridium(III) (abbreviation: [Ir(mpmppm)2(acac)]), represented by the structural formula (ix), was deposited by co-evaporation, resulting in a weight ratio of 2mDBTBPDBq-II to PCBBiF and [Ir(mpmppm)2(acac)] of 0.8:0.2:0.06. This formed a second light-emitting layer. The thickness of the second light-emitting layer was 40 nm.

[0257] Then, 2mDBTBPDBq-II was deposited by evaporation to a thickness of 15 nm on the second light-emitting layer. BPhen was also deposited by evaporation to a thickness of 20 nm on each of the light-emitting elements 1 to 3. BPhen was also deposited by evaporation to a thickness of 15 nm on each of the light-emitting reference elements 1 to 3. In this way, a second electron transport layer was formed.

[0258] Lithium fluoride was then deposited by evaporation to a thickness of 1 nm, forming an electron injection layer. Silver and magnesium were then deposited by co-evaporation to a thickness of 15 nm at a volume ratio of 1:0.1 (silver:magnesium). Subsequently, ITO was deposited by sputtering to a thickness of 70 nm. This created a second electrode (a semi-transparent and semi-reflective electrode). The preceding steps produced light-emitting elements 1 to 3 and light-emitting reference elements 1 to 3. It should be noted that all of the preceding evaporation steps were carried out using a resistance heating process.

[0259] The element structures of the light-emitting elements 1 to 3 and the light-emitting comparison elements 1 to 3 are shown below. [Table 1] reflektierendeElektrode Lochinjektionsschicht ersteLochtransportschicht erste Lichtemittierende Schicht ersteElektronentransportschicht APC ITSO PCPPn: MoOx1:0,5 PCPPn cgDBCzPA : *11:0,05 cgDBCzPA BPhen 100 nm *3 *4 10 nm 25 nm 5 nm 15 nm *6 folgt Zwischenschicht zweiteLochtransportschicht second light-emitting layer second electron transport layer Li2O CuPC DBT3P-IIMoOx1:0.5 BPAFLP 2mDBTBPDBq-II: PCBBiF: [Ir(mpmppm)2(acac)]0.8:0.2:0.06 2mDBTBPDBq-II BPhen 0.1 nm 2 nm 12.5 nm 20 nm 40 nm 15 nm *5 *6 *7 follows Electron injection layer semi-transparent and semi-reflective electrode Color filter LiF Ag:Mg1:0.1 ITO *2 1 nm 15 nm 70 nm *7 *1 Light-emitting elements 1 to 3: 1.6BnfAPrn-03 Light-emitting reference elements 1 to 3: 1.6 mMemFLPAPRn *2 Light-emitting element 1 and light-emitting comparison element 1: 0.8 µm Light-emitting element 2 and light-emitting comparison element 2: Blue 0,8 µm Light-emitting element 3: Green 1.3 µm, light-emitting Reference element 3: Red 2.4 µm *3 Light-emitting element 1: 30 nm, Light-emitting element 2: 80 nm, Light-emitting element 3: 30 nm Light-emitting reference element 1: 30 nm, light-emitting Reference element 2: 60 nm, light-emitting reference element 3: 60 nm *4 Light-emitting element 1: 60 nm, Light-emitting element 2: 47.5 nm, Light-emitting element 3: 40 nm Light-emitting reference element 1: 55 nm, light-emitting Reference element 2: 70 nm, light-emitting reference element 3: 45 nm *5 Light-emitting elements 1 to 3: 20 nm Light-emitting reference elements 1 to 3: 15 nm

[0260] The light-emitting elements 1 to 3 and the light-emitting comparison elements 1 to 3 were each sealed using a glass substrate in a glove box containing a nitrogen atmosphere to prevent exposure to air (in particular, a sealing material was applied in such a way as to enclose the element, and during sealing a UV treatment (with 365 nm UV light at 6 J / cm²) was applied). 2 ) and a heat treatment was carried out for 1 hour at 80 °C). The initial properties of these light-emitting elements were then measured. It should be noted that the measurement was carried out at room temperature (in an atmosphere maintained at 25 °C).

[0261] Fig. Figure 16 shows luminance-current density properties of the light-emitting elements 1 to 3. Fig. Figure 17 shows their power efficiency-luminance properties, Fig.Figure 18 shows their luminance-voltage properties, Fig. Figure 19 shows their current-voltage properties, and Fig. Figure 20 shows their chromaticity coordinates.

[0262] Fig. Figure 21 shows luminance-current density properties of the light-emitting comparison elements 1 to 3. Fig. Figure 22 shows their power efficiency-luminance properties. Fig. Figure 23 shows their luminance-voltage properties. Fig. Figure 24 shows their current-voltage characteristics, and Fig. Figure 25 shows their chromaticity coordinates.

[0263] As in Fig. 20 and Fig. Figure 25 shows that the light-emitting element 2, which contains 1,6BnfAPrn-O3, has chromaticity coordinates of (x, y) = (0.152, 0.037) at approximately 1000 cd / m². 2The light-emitting reference element 2, which contains 1.6 mMemFLPAPrn, exhibits chromaticity coordinates of (x, y) = (0.160, 0.087). This shows that light-emitting element 2 displays a deeper blue emission than light-emitting reference element 2.

[0264] Fig. Figure 26 shows the emission spectrum of 1,6BnfAPrn-O3 in a toluene solution of 1,6BnfAPrn-O3. Fig. According to

[26] , the peak wavelength of the emission spectrum of 1,6BnfAPrn-O3 in the toluene solution was 450 nm. The full width at half maximum (FWHM) of the emission spectrum was 40 nm. In contrast, the peak wavelength of 1,6mMemFLPAPRn in the toluene solution, which was used for the light-emitting reference elements, was 461 nm.

[0265] The power consumption of the light-emitting devices containing the light-emitting elements to obtain white light with a chromaticity of approximately D65 was then calculated. The power consumption of the light-emitting devices was calculated under the following conditions. [Table 2] Screen size 4.3 (inches) (aspect ratio 16:9) screen area 51,0 (cm 2 ) Opening ratio 35 % Completely white (effective luminance) 300 (cd / m 2 )

[0266] Table 3 shows the calculation results for the light-emitting device of this example, and Table 4 shows the calculation results for the light-emitting device of the comparison example. [Table 3] Light-emitting element Chromaticityx Chromaticity effective luminance (cd / m²) 2 ) intrinsic luminance (cd / m²) 2 ) Power efficiency (cd / A) 1 (Yellow) 0,449 0,545 253 2895 142,6 2 (Blue) 0,152 0,038 15 175 2,3 3 (Green) 0,336 0,653 31 358 38,7 completely white 0,313 0,329 300 - - *8 follows Current density (mA / cm³) 2 ) Current (mA) Voltage (V) Power consumption (mW) 2,0 9,1 5,92 53,6 7,7 34,4 6,38 219,2 0,9 4,1 5,50 22,7 - 47,5 - 295,6 *8 [Table 4] Light-emitting comparison element Chromaticity x Chromaticity y effective luminance (cd / m²) 2 ) intrinsic luminance (cd / m²) 2 ) Power efficiency (cd / A) 1 (Yellow) 0,414 0,582 237 2705 126,7 2 (Blue) 0,160 0,088 38 435 5,2 3 (Red) 0,656 0,344 25 289 19,1 completely white 0,313 0,329 300 - - *9 follows Current density (mA / cm³) 2 ) Current (mA) Voltage (V) Power consumption (mW) 2,1 9,5 5,96 56,8 8,4 37,5 7,05 264,3 1,5 6,7 5,82 39,1 - 53,7 - 360,2 *9

[0267] In the preceding calculations, the effective luminance was determined by the following calculation: intrinsic luminance × aperture ratio × 1 / 4 (the area ratio of each subpixel (assuming that in light-emitting devices, one pixel contains four subpixels of red, green, blue, and yellow)). The current was determined by the following calculation: current density × screen area × aperture ratio × 1 / 4 (the area ratio of each subpixel). The power consumption of a display section was determined by the following calculation: current × voltage.

[0268] According to Table 3 and Table 4, the luminance of a blue emission (emission of light-emitting element 2), which is required to obtain white light with a chromaticity of approximately D65, was very low for the light-emitting device of this example, 15 cd / m². 2, while the luminance of a blue emission (emission of the light-emitting reference element 2), which is required to obtain white light with a chromaticity of approximately D65, is 38 cd / m² for the light-emitting device of the reference example. 2 This is because the chromaticity of the blue emission was improved by using 1,6BnfAPrn-03, a fluorescent substance described in embodiments 1 and 2, as the blue emission material, thus reducing the effective luminance of the blue emission required for white light. Consequently, the power consumption of the light-emitting element 2, required to obtain white light, was significantly reduced.

[0269] The power consumption of light-emitting element 3, required to obtain white light with a chromaticity of approximately D65, was very low at 22.7 mW, while the power consumption of the comparison light-emitting element 3, required to obtain white light with a chromaticity of approximately D65, was 39.1 mW. This also shows that the power consumption of the light-emitting device in this example is lower.

[0270] The reason for this is as follows: A deep blue emission was obtained from light-emitting element 2, and therefore the color of an emission obtained by combining the blue emission and a yellow emission from light-emitting element 1 changed, and the color of a third emission, required to obtain white light with a chromaticity of approximately D65, also changed. In the light-emitting device of this example, a green emission was required as the third emission. In contrast, the light-emitting device of the comparison example required a red emission as the third emission.The proportion of luminance required for the green emission of the light-emitting device of this example to obtain white light is higher than the proportion of luminance required for the red emission of the light-emitting device of the comparison example to obtain white light.

[0271] However, the luminosity of the green emission is higher than that of the red emission, and therefore the power efficiency of light-emitting element 3, which represents the green emission, is approximately twice that of the reference light-emitting element 3, which represents the red emission. Therefore, even if the proportion of the luminance of the third emission (emission of light-emitting element 3) required to obtain white light is increased in the light-emitting device of this example, the power consumption of light-emitting element 3 can be lower than that of the reference light-emitting element 3.

[0272] The effective luminance of light-emitting element 2 (blue) and that of light-emitting element 3 (green) required to obtain white light with a chromaticity of approximately D65 at a luminance of 300 cd / m² 2The required values ​​for the light-emitting element in this example are lower than those of light-emitting reference element 2 (blue) or light-emitting reference element 3 (red), which are necessary to obtain white light with a chromaticity of approximately D65 at a luminance of 300 cd / m². 2The required luminance for the light-emitting element in the comparison example is lower, but this shortfall can be compensated for by the high luminance of a yellow emission from light-emitting element 1. Since the power efficiency of light-emitting element 1, which produces a yellow emission, is very high, any increase in power consumption due to the increased required luminance can be offset by a reduction in the luminance required for light-emitting elements 2 and 3. Consequently, the power consumption of the light-emitting device in this example can be reduced.

[0273] As a result, the power consumption of the light-emitting device of this example, which performs a white display, excluding the power consumption of the driver FETs, was 5.8 mW / cm². 2 , and the one that includes the power consumption of the driver FETs was 14 mW / cm². 2Since the power consumption of the light-emitting device of the comparative example, which performs a white display, excluding the power consumption of the driver FETs, is 7.1 mW / cm² 2 The amount was 16 mW / cm², and the one that includes the power consumption of the driver FETs was 16 mW / cm². 2 Since the power consumption of the light-emitting device in this example may be approximately 10% to 20% lower than that of the comparison example, it should be noted that the power consumption of the light-emitting devices with driver FETs was estimated from a voltage between an anode and a cathode (the sum of the voltages of sections of the light-emitting elements and the driver FETs), which was 15 V.

[0274] Since the blue light-emitting element consumes much more energy than the light-emitting elements of the other colors, the effect of reducing power consumption due to a change in chromaticity is very significant. Furthermore, power consumption can also be reduced by adjusting the balance of the emission colors to obtain white light with a chromaticity of approximately D65 and by modifying the luminance ratios. As a result, the power consumption of the light-emitting device of this example, which contains a fluorescent substance as described in embodiment 1, can be low. [Example 2]

[0275] This example describes the results of calculating the power consumption of light-emitting devices that perform a white display. The light-emitting device of the present invention uses light-emitting elements (a red light-emitting element: light-emitting element 4, a yellow light-emitting element: light-emitting element 5, a green light-emitting element: light-emitting element 6, and a blue light-emitting element: light-emitting element 7). The light-emitting device of a comparative example uses light-emitting elements (a red light-emitting element: comparison element 4, a green light-emitting element: comparison element 5, and a blue light-emitting element: comparison element 6).

[0276] Structural formulas of organic compounds used for light-emitting elements 4 to 7 and light-emitting reference elements 4 to 6 are shown below. (Method for producing the light-emitting elements 4 to 7 and the light-emitting comparison elements 4 to 6)

[0277] First, an alloy film of silver (Ag), palladium (Pd), and copper (Cu) (hereinafter referred to as APC) was formed over a glass substrate by a sputtering process to create a first electrode (reflective electrode). The thickness of the first electrode was 100 nm, and the electrode area was 2 mm × 2 mm.

[0278] Subsequently, a transparent conductive film of indium tin oxide containing silicon oxide was formed over the first electrode by a sputtering process. The thickness of the transparent conductive film of light-emitting element 4 (red) was 80 nm, that of light-emitting element 5 (yellow) was 45 nm, that of light-emitting element 6 (green) was 45 nm, and that of light-emitting element 7 (blue) was 80 nm. The thickness of the transparent conductive film of light-emitting reference element 4 (red) was 85 nm, that of light-emitting reference element 5 (green) was 45 nm, and that of light-emitting reference element 6 (blue) was 110 nm.

[0279] Then, as a pretreatment for the evaporation of an organic compound layer, a surface of the substrate, which was equipped with the reflective electrode and the transparent conductive film, was washed with water, baking was carried out for one hour at 200 °C, and then a UV ozone treatment was carried out for 370 seconds.

[0280] The substrate was then transferred to a vacuum evaporation device, in which the pressure was increased to approximately 10 -4 The Pa had been reduced and was heated for 30 minutes in a vacuum at 170 °C in a heating chamber of the vacuum evaporation device, and then the substrate was cooled for about 30 minutes.

[0281] The substrate was then attached to a substrate holder in the vacuum evaporation apparatus such that the surface on which the transparent conductive film had formed faced downwards. The pressure in the vacuum evaporation apparatus was set to approximately 10-4Pa reduced. Subsequently, 3-[4-(9-Phenanthryl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPPn), which is represented by the structural formula (i), and molybdenum(VI) oxide were deposited on the transparent conductive film by co-evaporation, using resistance heating, thereby forming a first hole injection layer. The thickness of the first hole-injected layer of light-emitting element 4 (red) was 30 nm, that of light-emitting element 5 (yellow) was 40 nm, that of light-emitting element 6 (green) was 22.5 nm, and that of light-emitting element 7 (blue) was 50 nm. The thickness of the first hole-injected layer of light-emitting reference element 4 (red) was 10 nm, that of light-emitting reference element 5 (green) was 10 nm, and that of light-emitting reference element 6 (blue) was 15 nm. The weight ratio of PCPPn to molybdenum oxide was set to 1:0.5.

[0282] Subsequently, PCPPn was deposited on the first hole injection layer, forming a first hole transport layer. The thickness of the first hole transport layer for light-emitting elements 4 to 7 was 10 nm, and the thickness of the first hole transport layer for light-emitting comparison elements 4 to 6 was 15 nm.

[0283] On the first hole transport layer, a first light-emitting layer was formed by deposition of 7-[4-(10-Phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), which is represented by structural formula (ii), and N,N'-(Pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), which is represented by structural formula (iii), in a thickness of 25 nm, such that the weight ratio of cgDBCzPA to 1,6BnfAPrn-03 was 1:0.05.

[0284] Then, a first electron transport layer was formed over the first light-emitting layer in such a way that cgDBCzPA was deposited at a thickness of 5 nm and bathophenanthroline (abbreviation: BPhen), which is represented by the structural formula (iv), was deposited at a thickness of 15 nm.

[0285] After the first electron transport layer was formed, lithium oxide (Li₂O) was deposited by evaporation to a thickness of 0.1 nm. Then, copper phthalocyanine (abbreviation: CuPc), represented by structural formula (xi), was deposited by evaporation to a thickness of 2 nm. Subsequently, 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT₃P-II), represented by structural formula (v), and molybdenum oxide were deposited by co-evaporation, resulting in a weight ratio of DBT₃P-II to molybdenum oxide of 1:0.5. This formed an intermediate layer with a thickness of 12.5 nm.

[0286] Subsequently, 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), which is represented by the structural formula (vi), was deposited on the intermediate layer by evaporation to a thickness of 20 nm, thereby forming a second hole transport layer.

[0287] After the second hole transport layer had formed, 2-[3'-(Dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), represented by structural formula (vii), N-(1,1'-Biphenyl-4-yl)-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluorene-2-amine (abbreviation: PCBBiF), represented by structural formula (viii), and Bis{2-[5-methyl-6-(2-methylphenyl)-4-pyrimidinyl-κN3]phenyl-κC}(2,4-pentanedionato-κ 2 Iridium(III) (abbreviation: [Ir(mpmppm)2(acac)]), represented by the structural formula (ix), was deposited by co-evaporation, resulting in a weight ratio of 2mDBTBPDBq-II to PCBBiF and [Ir(mpmppm)2(acac)] of 0.8:0.2:0.06. This formed a second light-emitting layer. The thickness of the second light-emitting layer was 40 nm.

[0288] After the second hole transport layer had formed, 2mDBTBPDBq-II, PCBBiF and Bis[2-(6-tert-butyl-4-pyrimidinyl-κN3)phenyl-κC](2,4-pentanedionato-κ) were added to each of the light-emitting reference elements 4 to 6. 2 O,O')iridium(III) (abbreviation: [Ir(tBuppm)2(acac)]), which is represented by the structural formula (xii), was deposited by co-evaporation to a thickness of 20 nm. Subsequently, 2mDBTBPDBq-II and Bis{4,6-dimethyl-2-[5-(2,6-dimethylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN]pheny I-κC}(2,8-dimethyl-4,6-nonandionato-κ 2 Ir(dmdppr-dmp)2(divm) (abbreviation: [Ir(dmdppr-dmp)2(divm)]) was deposited by cobalt evaporation to a thickness of 20 nm, resulting in a weight ratio of 2mDBTBPDBq-II to [Ir(dmdppr-dmp)2(divm)] of 1:0.06. In this way, a second light-emitting layer was formed.

[0289] For each of the light-emitting elements 4 to 7, 2mDBTBPDBq-II was deposited on the second light-emitting layer by evaporation to a thickness of 15 nm. For each of the light-emitting reference elements 4 to 6, 2mDBTBPDBq-II was deposited on the second light-emitting layer by evaporation to a thickness of 30 nm. For each of the light-emitting elements 4 to 7, BPhen was also deposited on the 2mDBTBPDBq-II by evaporation to a thickness of 20 nm. For each of the light-emitting reference elements 4 to 6, BPhen was also deposited on the 2mDBTBPDBq-II by evaporation to a thickness of 15 nm. In this way, a second electron transport layer was formed.

[0290] Lithium fluoride was then deposited by evaporation to a thickness of 1 nm, forming an electron injection layer. Silver and magnesium were then deposited by co-evaporation to a thickness of 15 nm at a volume ratio of 1:0.1 (silver:magnesium). Subsequently, ITO was deposited by sputtering to a thickness of 70 nm. This created a second electrode (a semi-transparent and semi-reflective electrode). The preceding steps produced light-emitting elements 4 to 7 and light-emitting reference elements 4 to 6. It should be noted that all of the preceding evaporation steps were carried out using a resistance heating process.

[0291] The element structures of the light-emitting elements 4 to 7 and the light-emitting comparison elements 4 to 6 are shown below. [Table 5] reflective electrode Hole injection layer first hole transport layer first light-emitting layer first electron transfer layer sport- APC ITSO PCPPn: MoOx1:0.5 PCPPn cgDBCzPA :1,6BnfAPrn-031:0,05 cgDBCzPA : BPhen 100 nm *10 *11 *12 25 nm 5 nm 15 nm *17 follows Intermediate shift second hole transport layer second light-emitting layer second electron transport layer Li2O CuPC DBT3P-II: MoOx1:0.5 BPAFLP *13 2mDBTBPDBq-II BPhen 0.1 nm 2 nm 12.5 nm 20 nm *14 *15 *17 *18 follows Electron injection layer semi-transparent and semi-reflective electrode Color filter LiF Ag:Mg1:0.1 ITO *16 1 nm 15 nm 70 nm *18 *10 Light-emitting element 4: 80 nm, Light-emitting element 5: 45 nm, Light-emitting element 6: 45 nm, light-emitting element 7: 80 nm Light-emitting reference element 4: 85 nm, light-emitting Reference element 5: 45 nm, light-emitting reference element 6: 110 nm *11 Light-emitting element 4: 30 nm, Light-emitting element 5: 40 nm, Light-emitting element 6: 22.5 nm, light-emitting element 7: 50 nm Light-emitting reference element 4: 10 nm, light-emitting Reference element 5: 10 nm, light-emitting reference element 6: 15 nm *12 light-emitting elements 4 to 7: 10 nm, light-emitting Reference elements 4 to 6: 15 nm *13 Light-emitting elements 4 to 7 2mDBTBPDBq-II:PCBBiF:[Ir(mpmppm)2(acac)] = 0.8:0.2:0.06, 40 nm Light-emitting reference elements 4 to 6 2mDBTBPDBq-II:PCBBiF:[Ir(tBuppm)2(acac)] = 0.7:0.3:0.06, 20 nm + 2mDBTBPDBq-II:[Ir(dmdppr-dmp)2(divm)] = 1:0.06, 20 nm *14 Light-emitting elements 4 to 7: 15 nm, light-emitting Reference elements 4 to 6: 30 nm *15 light-emitting elements 4 to 7: 20 nm, light-emitting Reference elements 4 to 6: 15 nm *16 Light-emitting element 4 and light-emitting comparison element 4: Red 2,4 µm Light-emitting element 5: Yellow 0.8 µm Light-emitting element 6 and light-emitting comparison element 5: Green 1.3 µm Light-emitting element 7 and light-emitting comparison element 6: Blue 0,8 µm

[0292] The light-emitting elements 4 to 7 and the light-emitting comparison elements 4 to 6 were each sealed using a glass substrate in a glove box containing a nitrogen atmosphere to prevent exposure to air (in particular, a sealing material was applied in such a way as to enclose the element, and during sealing a UV treatment (with 365 nm UV light at 6 J / cm²) was applied). 2 ) and a heat treatment was carried out for 1 hour at 80 °C). The initial properties of these light-emitting elements were then measured. It should be noted that the measurement was carried out at room temperature (in an atmosphere maintained at 25 °C).

[0293] Fig. Figure 28 shows luminance-current density properties of the light-emitting elements 4 to 7. Fig. Figure 29 shows their power efficiency-luminance properties, Fig.Figure 30 shows their luminance-voltage properties, Fig. Figure 31 shows their current-voltage characteristics, and Fig. Figure 32 shows their chromaticity coordinates.

[0294] Fig. Figure 33 shows luminance-current density properties of the light-emitting comparison elements 4 to 6. Fig. Figure 34 shows their power efficiency-luminance properties, Fig. Figure 35 shows their luminance-voltage properties, and Fig. Figure 36 shows their current-voltage properties.

[0295] The power consumption of the light-emitting devices containing the light-emitting elements to obtain white light with a chromaticity of approximately D65 was then calculated. The power consumption of the light-emitting devices was calculated under the following conditions. [Table 6] Screen size 4.3 (inches) (aspect ratio 16:9) screen area 51,0 (cm 2 ) Opening ratio 35 % Completely white (effective luminance) 300 (cd / m 2 )

[0296] Table 7 shows the calculation results for the light-emitting device of this example, and Table 8 shows the calculation results for the light-emitting device of the comparison example. [Table 7] Light-emitting element Voltage (V) Current density (mA / cm³) 2 ) CIE chromaticity (x, y) Luminance (cd / m²) 2 ) Power efficiency (cd / A) Power consumption (mW) 4 (Red) - - (0,67, 0,33) - 22,1 0 5 (Yellow) 5,9 2,2 (0,44, 0,55) 2956 137 57,2 6 (Green) 5,3 0,23 (0,33, 0,66) 139 61,1 5,3 7 (Blue) 6,4 7,2 (0,17, 0,07) 334 4,66 203,7 [Table 8] Light-emitting comparison element Voltage (V) Current density (mA / cm³) 2 ) CIE chromaticity (x, y) intrinsic luminance (cd / m²) 2 ) Power efficiency (cd / A) Power consumption (mW) 4 (Red) 6,0 2,1 (0,67, 0,33) 572 27,8 73,7 5 (Green) 6,3 2,7 (0,29, 0,70) 1792 67,2 99,2 6 (Blue) 6,6 5,6 (0,16, 0,06) 208 3,72 221,1

[0297] In the preceding calculations, the effective luminance was determined by the following calculation: intrinsic luminance × aperture ratio × 1 / 4 (the area ratio of each subpixel (assuming that in light-emitting devices, one pixel contains four subpixels of red, green, blue, and yellow)). The current was determined by the following calculation: current density × screen area × aperture ratio × 1 / 4 (the area ratio of each subpixel). The power consumption of a display section was determined by the following calculation: current × voltage.

[0298] According to Tables 7 and 8, the power consumption to obtain white light in this example's light-emitting device was 266 mW, and in the comparison example's light-emitting device, it was 394 mW; therefore, this example's light-emitting device consumes less energy than the comparison example's. In the comparison example's light-emitting device, both light-emitting reference element 4 (red) and light-emitting reference element 5 (green) require an intrinsic luminance of certain proportions to emit white light. In contrast, in this example's light-emitting device, light-emitting element 4 (red) does not emit any light, and the emission luminance of light-emitting element 6 (green) is very low, at 139 cd / m². 2To emit white light, they hardly affect the power consumption. That is to say, in the light-emitting device of this example, essentially only light-emitting element 7 (blue) and light-emitting element 5 (yellow) emit light to emit white light. Since the power efficiency of light-emitting element 5 (yellow) is very high, 137 cd / A, the power consumption of the light-emitting device of this example was much lower than that of the light-emitting device of the comparison example, even though the power consumption of the blue-light-emitting elements of the light-emitting devices of this example and the comparison example is essentially the same. [Example 3]

[0299] The estimated results of the deterioration of luminance are shown in the case where a light-emitting device produces a white display with a chromaticity of approximately D65 at a luminance of 300 cd / m². 2 In this example, drive tests were performed on a light-emitting element 8 (blue) and a light-emitting element 9 (yellow), which have the same structure as a light-emitting element in the light-emitting device, under a constant current density condition. The initial luminance of light-emitting element 8 was set to 300 cd / m². 2 adjusted, and that of light-emitting element 9 was set to 3000 cd / m² 2These values ​​were set. These values ​​were close to the luminance values ​​required to perform a white display with a chromaticity of approximately D65 on the light-emitting device under the following conditions. The reason the drive tests were performed assuming a white display was being performed is that light emission for a white display must be continuous, and therefore the elements degrade most rapidly during a white display. [Table 9] Screen size 4.3 (inches) (aspect ratio 16:9) screen area 51,0 (cm 2 ) Opening ratio 35 % Completely white (effective luminance) 300 (cd / m 2 )

[0300] It should be noted that the drive test was not performed on a red light emitting element or a green light emitting element, since light is extracted from a yellow light emitting layer and they are therefore expected to exhibit deterioration behavior similar to that of a yellow light emitting element, and since the luminance required for the red light emitting element and the green light emitting element in the white display with a chromaticity of approximately D65, as in Example 2, is low and therefore does not affect reliability.

[0301] Structural formulas of organic compounds used for light-emitting elements 8 and 9 are shown below. (Method for producing the light-emitting elements 8 and 9)

[0302] First, an alloy film of silver (Ag), palladium (Pd), and copper (Cu) (hereinafter referred to as APC) was formed over a glass substrate by a sputtering process to create a first electrode (reflective electrode). The thickness of the first electrode was 100 nm, and the electrode area was 2 mm × 2 mm.

[0303] Subsequently, a transparent conductive film of indium tin oxide containing silicon oxide was formed over the first electrode by a sputtering process. The thickness of the transparent conductive film for light-emitting element 8 (blue) was 85 nm, and that for light-emitting element 9 (yellow) was 65 nm.

[0304] Then, as a pretreatment for the evaporation of an organic compound layer, a surface of the substrate, which was equipped with the reflective electrode and the transparent conductive film, was washed with water, baking was carried out for one hour at 200 °C, and then a UV ozone treatment was carried out for 370 seconds.

[0305] The substrate was then transferred to a vacuum evaporation device, in which the pressure was increased to approximately 10 -4 The Pa had been reduced and was heated for 30 minutes in a vacuum at 170 °C in a heating chamber of the vacuum evaporation device, and then the substrate was cooled for about 30 minutes.

[0306] The substrate was then mounted on a substrate holder in the vacuum evaporation apparatus such that the surface on which the transparent conductive film had formed faced downwards. Subsequently, 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), represented by structural formula (xiv), and molybdenum(VI) oxide were deposited onto the transparent conductive film by co-evaporation using resistance heating, forming a first injection layer. The thickness of the first injection layer for light-emitting element 8 (blue) was 40 nm, and that for light-emitting element 9 (yellow) was 45 nm. The weight ratio of PCzPA to molybdenum oxide was adjusted to 1:0.5.

[0307] Subsequently, PCzPA was deposited onto the first hole injection layer, forming a first hole transport layer. The thickness of the first hole transport layer was 20 nm.

[0308] On the first hole transport layer, a first light-emitting layer was formed by deposition of 7-[4-(10-Phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), which is represented by structural formula (ii), and N,N'-(Pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), which is represented by structural formula (iii), in a thickness of 25 nm, such that the weight ratio of cgDBCzPA to 1,6BnfAPrn-03 was 1:0.03.

[0309] Then, a first electron transport layer was formed over the first light-emitting layer in such a way that cgDBCzPA was deposited in a thickness of 10 nm and bathophenanthroline (abbreviation: BPhen), which is represented by the structural formula (vi), was deposited in a thickness of 10 nm.

[0310] After the first electron transport layer was formed, lithium oxide (Li₂O) was deposited by evaporation to a thickness of 0.1 nm. Then, copper phthalocyanine (abbreviated CuPc), represented by the structural formula (xi), was deposited by evaporation to a thickness of 2 nm. Subsequently, PCzPA and molybdenum oxide were deposited by co-evaporation, resulting in a weight ratio of PCzPA to molybdenum oxide of 1:0.5. This formed an intermediate layer with a thickness of 12.5 nm.

[0311] Subsequently, PCzPA was deposited on the intermediate layer by evaporation to a thickness of 20 nm, forming a second hole transport layer.

[0312] After the second hole transport layer had formed, 2-[3'-(Dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), which is represented by structural formula (vii), N-(1,1'-Biphenyl-4-yl)-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluorene-2-amine (abbreviation: PCBBiF), which is represented by structural formula (viii), and Bis{2-[5-methyl-6-(2-methylphenyl)-4-pyrimidinyl-κN3]phenyl-κC}(2,4-pentanedionato-κ 2Iridium(III) (abbreviation: [Ir(mpmppm)2(acac)]), represented by the structural formula (ix), was deposited by co-evaporation, resulting in a weight ratio of 2mDBTBPDBq-II to PCBBiF and [Ir(mpmppm)2(acac)] of 0.8:0.2:0.06. This formed a second light-emitting layer. The thickness of the second light-emitting layer was 40 nm.

[0313] On the second light-emitting layer, 2mDBTBPDBq-II was deposited by evaporation to a thickness of 15 nm. BPhen was deposited on 2mDBTBPDBq-II by evaporation to a thickness of 20 nm. In this way, a second electron transport layer was formed.

[0314] Lithium fluoride was then deposited by evaporation to a thickness of 1 nm, forming an electron injection layer. Silver and magnesium were then deposited by co-evaporation to a thickness of 15 nm at a volume ratio of 1:0.1 (silver:magnesium). Subsequently, ITO was deposited by sputtering to a thickness of 70 nm. This created a second electrode (a semi-transparent and semi-reflective electrode). The preceding steps produced light-emitting element 8 (blue) and light-emitting element 9 (yellow). It should be noted that all of the preceding evaporation steps were carried out using a resistance heating process.

[0315] The elemental structures of light-emitting elements 8 and 9 are shown below. [Table 10] reflective electrode Hole injection layer first hole transport layer first light-emitting layer first electron transport layer APC ITSO PCzPA: MoOx PCzPA cgDBCzPA: 1,6BnfAPrn-03 cgDBCzPA BPhen 100 nm *19 1:0,5*20 20 nm 1:0.0325 nm 10 nm 10 nm *22 follows Intermediate shift second hole transport layer second light-emitting layer second electron transport layer Li2O CuPC PCzPA: MoOx PCzPA 2mDBTBPDBq-II: PCBBiF: [Ir(mpmppm)z(acac)] 2mDBTBPDBq-II BPhen 1:0,5 0,8:0,2:0,06 0.1 nm 2 nm 12.5 nm 20 nm 40 nm 15 nm 20 nm *22 *23 follows Electron injection layer semi-transparent and semi-reflective electrode Color filter LiF LiF Ag:Mg ITO *21 1:0,1 1nm 15 nm 70 nm *23 *19 Light-emitting element 8: 85 nm, Light-emitting element 9: 65 nm *20 Light-emitting element 8: 40 nm, Light-emitting element 9: 45 nm *21 Light-emitting element 8: Blue 0.8 µm, Light-emitting element 9: Yellow 0,8 µm

[0316] Light-emitting element 8 (blue) and light-emitting element 9 (yellow) were each sealed using a glass substrate in a glove box containing a nitrogen atmosphere to prevent exposure to air (in particular, a sealing material was applied to enclose the element, and during sealing, a UV treatment (with 365 nm UV light at 6 J / cm²) was applied). 2 ) and a heat treatment was carried out for 1 hour at 80 °C). The initial properties of these light-emitting elements were then measured. It should be noted that the measurement was carried out at room temperature (in an atmosphere maintained at 25 °C). For light-emitting element 8, light was measured through a blue color filter. For light-emitting element 9, light was measured through a yellow color filter.

[0317] Fig.Figure 39 shows luminance-current density properties of light-emitting element 8 (blue) and light-emitting element 9 (yellow). Fig. Figure 40 shows their power efficiency-luminance properties. Fig. Figure 41 shows their luminance-voltage properties, Fig. Figure 42 shows their current-voltage characteristics, and Fig. Figure 43 shows their emission spectra. As shown in these diagrams, light-emitting element 8 and light-emitting element 9 exhibit advantageous properties.

[0318] Subsequently, drive tests were carried out on the light-emitting element 8 (blue) and the light-emitting element 9 (yellow) under conditions where the initial luminance of the light-emitting element 8 was 300 cd / m². 2 The initial luminance of the light-emitting element was 9,300 cd / m² 2 was, and the current density was constant. Fig.Figure 44 shows a change in luminance with respect to the operating time, with the initial luminance set to 100%.

[0319] As in Fig. As shown in Figure 44, it took approximately 2300 hours for the luminance of light-emitting element 8 to decrease to 90% of the initial luminance, and it took approximately 6000 hours for the luminance of light-emitting element 9 to decrease to 90% of the initial luminance. These results indicate that the light-emitting device consumes very little energy, its luminance deteriorates only slightly, and it exhibits a reliability high enough for practical use. [Example 4]

[0320] In this example, a 254 ppi light-emitting device using a color filter method was actually manufactured. Fig.Figure 37 is a photograph of the manufactured light-emitting device. In each pixel, red, yellow, green, and blue subpixels, each with a size of 50 µm, are arranged in a 2 × 2 matrix. Fig. Figure 38 shows a comparison between the power consumption when displaying a still image in the light-emitting device of this example and that of a comparison example using a white color filter method employing red, green, and blue subpixels. The power consumption of screen sections displaying still images was measured at a peak luminance of 300 cd / m². 2 calculated.

[0321] Fig.As shown in Figure 38, it is clearly evident that the power consumption of the light-emitting device of this example is lower than that of the light-emitting device of the comparison example. In particular, the power consumption of the present invention is greatly reduced when an image is displayed in which a white display area occupies a large area. The power consumption is greatest when displaying the image in which the white display area occupies a large area; the higher the proportion of a black display area, the lower the power consumption per unit area becomes in each screen. This is because an OLED does not emit light when displaying black, whereas a liquid crystal display requires a backlight to remain switched on. (Reference example)

[0322] This reference example describes a method for the preparation of N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), an organic compound used in this example. It should be noted that a structure of 1,6BnfAPrn-03 is shown below. <Schritt 1: Herstellung von 6-Jodbenzo[b]naphtho[1,2-d]furan>

[0323] 8.5 g (39 mmol) of benzo[b]naphtho[1,2-d]furan were placed in a 500 ml three-necked flask, and the air in the flask was replaced with nitrogen. Then, 195 ml of tetrahydrofuran were added. This solution was cooled to -75 °C. Subsequently, 25 ml (40 mmol) of n-butyllithium (a 1.59 mol / l n-hexane solution) were added dropwise to this solution. After the dropwise addition, the resulting solution was stirred for 1 hour at room temperature.

[0324] After a predetermined time, the obtained solution was cooled to -75 °C. A solution containing 10 g (40 mmol) of iodine dissolved in 40 ml of THF was then added dropwise. After this addition, the obtained solution was stirred for 17 hours while its temperature was gradually reduced to room temperature. After a predetermined time, an aqueous sodium thiosulfate solution was added to the mixture, and the obtained mixture was stirred for 1 hour. Subsequently, an organic layer of the mixture was washed with water and dried with magnesium sulfate. After drying, the mixture was gravity-filtered to obtain a solution. The obtained solution was suction-filtered through Celite (manufactured by Wako Pure Chemical Industries, Ltd., catalog no. 531-16855) and Florisil (manufactured by Wako Pure Chemical Industries, Ltd., catalog no. 540-00135) to obtain a filtrate.The obtained filtrate was concentrated to obtain a solid. The resulting solid was recrystallized from toluene to yield 6.0 g (18 mmol) of a white powder of the target compound in a 45% yield. A synthesis scheme for step 1 is presented below. <Schritt 2: Herstellung von 6-Phenylbenzo[b]naphtho[1,2-d]furan>

[0325] Into a 200 mL three-necked flask, 6.0 g (18 mmol) of 6-iodobenzo[b]naphtho[1,2-d]furan, 2.4 g (19 mmol) of phenylboronic acid, 70 mL of toluene, 20 mL of ethanol, and 22 mL of an aqueous potassium carbonate solution (2.0 mol / L) were added. This mixture was degassed by stirring while the pressure was reduced. After degassing, the air in the flask was replaced with nitrogen, and then 480 mg (0.42 mmol) of tetrakis(triphenylphosphine)palladium(0) were added to the mixture. The resulting mixture was stirred for 12 hours at 90 °C under a stream of nitrogen.

[0326] After a predetermined time, water was added to the mixture, and an aqueous layer was extracted with toluene. The extracted solution and the organic layer were combined, and the mixture was washed with water and then dried with magnesium sulfate. The mixture was gravity-filtered to obtain a filtrate. The filtrate was concentrated to obtain a solid, and the solid was dissolved in toluene. The resulting solution was suction-filtered through Celite (manufactured by Wako Pure Chemical Industries, Ltd., catalog no. 531-16855), Florisil (manufactured by Wako Pure Chemical Industries, Ltd., catalog no. 540-00135), and aluminum oxide to obtain a filtrate. The filtrate was concentrated to obtain a solid. The solid was recrystallized from toluene to yield 4.9 g (17 mmol) of a white solid of the target compound in a 93% yield.A synthesis scheme for step 2 is shown below. <Schritt 3: Herstellung von 8-Jod-6-phenylbenzo[b]naphtho[1,2,d]furan>

[0327] 4.9 g (17 mmol) of 6-phenylbenzo[b]naphtho[1,2-d]furan were placed in a 300 mL three-necked flask, and the air in the flask was replaced with nitrogen. Then, 87 mL of tetrahydrofuran (THF) were added. The resulting solution was cooled to -75 °C. Subsequently, 11 mL (18 mmol) of n-butyllithium (a 1.59 mol / L n-hexane solution) were added dropwise. After the addition, the solution was stirred at room temperature for 1 hour. After a predetermined time, the solution was cooled to -75 °C. Finally, a solution in which 4.6 g (18 mmol) of iodine had been dissolved in 18 mL of THF was added dropwise to the solution.

[0328] The resulting solution was stirred for 17 hours while its temperature was reduced to room temperature. After a predetermined time, an aqueous sodium thiosulfate solution was added to the mixture, and the resulting mixture was stirred for 1 hour. Subsequently, an organic layer of the mixture was washed with water and dried with magnesium sulfate. The mixture was gravity-filtered to obtain a filtrate. The filtrate was suction-filtered through Celite (manufactured by Wako Pure Chemical Industries, Ltd., catalog no. 531-16855), Florisil (manufactured by Wako Pure Chemical Industries, Ltd., catalog no. 540-00135), and aluminum oxide to obtain a filtrate. The filtrate was concentrated to obtain a solid. The solid was recrystallized from toluene to yield 3.7 g (8.8 mmol) of a white target solid in a 53% yield.A synthesis scheme for step 3 is shown below. <Schritt 4: Herstellung von 1,6BnfAPrn-03>

[0329] Into a 100 ml three-necked flask, 0.71 g (2.0 mmol) of 1,6-dibromopyrene, 1.0 g (10.4 mmol) of sodium tert-butoxide, 10 ml of toluene, 0.36 ml (4.0 mmol) of aniline, and 0.3 ml of tri(tert-butyl)phosphine (a 10 wt% hexane solution) were added, and the air in the flask was replaced with nitrogen. 50 mg (85 µmol) of bis(dibenzylideneacetone)palladium(0) was added to this mixture, and the resulting mixture was stirred for 2 hours at 80 °C.

[0330] After a predetermined time, 1.7 g (4.0 mmol) of 8-iodo-6-phenylbenzo[b]naphtho[1,2,d]furan, 180 mg (0.44 mmol) of 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (abbreviation: S-Phos), and 50 mg (85 µmol) of bis(dibenzylideneacetone)palladium(0) were added to the resulting mixture, and the mixture was stirred at 100 °C for 15 hours. After a predetermined time, the resulting mixture was filtered through Celite (manufactured by Wako Pure Chemical Industries, Ltd., catalog no. 531-16855) to obtain a filtrate. The filtrate was concentrated to obtain a solid. The recovered solid was washed with ethanol and recrystallized from toluene to obtain 1.38 g (1.4 mmol) of a yellow solid of the target substance in a yield of 71%.

[0331] 1.37 g (1.4 mmol) of the recovered yellow solid were purified by train sublimation. Sublimation purification was carried out by heating the yellow solid at 370 °C with an argon flow rate of 10 ml / min under a pressure of 2.3 Pa. As a result of sublimation purification, 0.68 g (0.70 mmol) of the yellow solid were recovered at a collection rate of 50%. A synthesis scheme for step 4 is shown below.

[0332] The results of the analysis of the yellow solid obtained in step 4 using nuclear magnetic resonance spectroscopy ( 1 The results (H-NMR) are given below. The results revealed that 1,6BnfAPrn-O3 was obtained.

[0333] 1H-NMR (Dichlormethane-d2, 500 MHz): δ = 6.88 (t, J = 7.7 Hz, 4H), 7.03–7.06 (m, 6H), 7.11 (t, J = 7.5 Hz, 2H), 7.13 (d, 7 J = 8, 2.2 (m, 8H), 7.37 (t, J = 8.0 Hz, 2H), 7.59 (t, J = 7.2 Hz, 2H), 7.75 (t, J = 7.7 Hz, 2H), 7.84 (d, J = 9.0 Hz, 2H), 7.8, J =88 ( (s, 2H), 8.07 (d, J = 8.0 Hz, 4H), 8.14 (d, J = 9.0 Hz, 2H), 8.21 (d, J = 8.0 Hz, 2H), 8.69 (d, J = 8.5 Hz, 2H). Erläuterung der Bezugszeichen

[0334] 101: first electrode, 102: second electrode, 103a: EL layer, 103b: EL layer, 104a: hole injection layer, 104b: hole injection layer, 105a: hole transport layer, 105b: hole transport layer, 106: light-emitting layer, 106a: light-emitting layer, 106b: light-emitting layer, 107a: electron transport layer, 107b: electron transport layer, 108a: electron injection layer, 108b: electron injection layer, 109: charge generation layer, 113: first light-emitting layer, 114: second light-emitting layer, 121: guest material (fluorescent material), 122: host material, 131: guest material (phosphorescent material), 132: first organic compound 133: second organic compound, 134: Exciplex, 501: substrate, 502: FET, 503: first electrode, 504: partition, 505: EL layer, 506R: light-emitting area, 506G: light-emitting area, 506B: light-emitting area, 506W: light-emitting area, 506Y: light-emitting area507R: Light-emitting element, 507G: Light-emitting element, 507B: Light-emitting element, 507W: Light-emitting element, 507Y: Light-emitting element, 508R: Color layer, 508G: Color layer, 508B: Color layer, 508Y: Color layer, 509: Black layer (black matrix), 510: Second electrode, 511: Sealing substrate, 601: Element substrate, 602: Pixel section, 603: Driver circuit section (source line driver circuit), 604a: Driver circuit section (gate line driver circuit), 604b: Driver circuit section (gate line driver circuit), 605: Sealant, 606: Sealing substrate, 607: Lead, 608: FPC (flexible printed circuit) 609: FET, 610: FET, 611: Switching FET, 612: Current-controlling FET, 613: First electrode (anode), 614: Insulator, 615: EL layer, 616: Second electrode (cathode), 617: Light-emitting element, 618: Space, 1100: Substrate, 1102B: First electrode, 1102G: First electrode, 1102Y: First electrode, 1102R: First electrode1103d: blue light-emitting layer, 1103e: hole injection and hole transport layer, 1103f: yellow light-emitting layer, 1103h: electron transport and electron injection layer, 1104: second electrode, 1105: black matrix, 1106B: color filter, 1106G: color filter, 1106Y: color filter, 1106R: color filter, 1101: sealing substrate, 2000: touchscreen, 2001: touchscreen, 2501: display section, 2502R: pixel, 2502t: transistor, 2503c: capacitor, 2503g: sampling line driver circuit, 2503t: transistor, 2509: FPC, 2510: substrate, 2511: line, 2519: connector 2521: Insulating layer, 2528: Partition, 2550R: Light-emitting element, 2560: Sealing layer, 2567BM: Opaque layer, 2567p: Anti-reflective layer, 2567R: Color layer, 2570: Substrate, 2580R: Light-emitting module, 2590: Substrate, 2591: Electrode, 2592: Electrode, 2593: Insulating layer, 2594: Conductor, 2595: Touch sensor, 2597: Adhesive layer, 2598: Conductor, 2599: Bonding layer2601: Pulse voltage output circuit, 2602: Current sensing circuit, 2603: Capacitor, 2611: Transistor, 2612: Transistor, 2613: Transistor, 2621: Electrode, 2622: Electrode, 7100: Television set, 7101: Housing, 7103: Display section, 7105: Foot, 7107: Display section, 7109: Control button, 7110: Remote control, 7201: Main body, 7202: Housing, 7203: Display section, 7204: Keyboard, 7205: External connection port, 7206: Pointing device, 7302: Housing, 7304: Display field, 7305: Icon showing the time, 7306: Other icon, 7311: Control knob, 7312: Operating button, 7313: Connection port, 7321: Band, 7322: Clasp, 7400: Mobile phone, 7401: Housing, 7402: Display section, 7403: Operating button, 7404: External connection section, 7405: Speaker, 7406: Microphone, 7407: Camera, 7500(1): Housing, 7500(2): Housing, 7501(1): Display section, 7501(2): Display section, 7502(1): Display section, 7502(2): Display section, 8001: Illumination device,8002: Lighting device, 8003: Lighting device, 8004: Lighting device, 9310: Portable information terminal, 9311: Display panel, 9312: Display area, 9313: Joint and 9315: Housing,

Claims

[1] Light-emitting device with bottom-emission structure, comprising: a substrate; a transistor, comprising: a first insulating layer over the substrate; an oxide semiconductor layer above the first insulating layer; a source electrode, a drain electrode and a gate electrode above the oxide semiconductor layer; and a second insulating layer over the oxide semiconductor layer, the source electrode and the drain electrode; an anode across the transistor; a first light-emitting element configured to emit light through a first color layer, so that blue light is extracted from the light-emitting device to the outside; a second light-emitting element configured to emit light through a second color layer, so that green light is extracted from the light-emitting device to the outside; a third light-emitting element configured to emit light through a third color layer, so that red light is extracted from the light-emitting device to the outside; a fourth light-emitting element, where: one of the source electrodes and the drain electrode is electrically connected to the anode, the anode is configured in such a way that it acts as the first electrode of one of the first to fourth light-emitting elements, the first to fourth light-emitting elements have the same structure comprising a first EL layer and a second EL layer with an intermediate charge-generating layer, The first EL layer contains a fluorescent substance that emits blue light, and the second EL layer contains a phosphorescent substance that emits yellow light. [2] Light-emitting device with bottom-emission structure, comprising: a substrate; a transistor, comprising: a first insulating layer over the substrate; an oxide semiconductor layer above the first insulating layer; a source electrode, a drain electrode and a gate electrode above the oxide semiconductor layer; and a second insulating layer over the oxide semiconductor layer, the source electrode and the drain electrode; an anode across the transistor; a first light-emitting element configured to emit light through a first color layer, so that blue light is extracted from the light-emitting device to the outside; a second light-emitting element configured to emit light through a second color layer, so that green light is extracted from the light-emitting device to the outside; a third light-emitting element configured to emit light through a third color layer, such that red light is extracted from the light-emitting device to the outside; and a fourth light-emitting element, wherein: one of the source electrodes and the drain electrode is electrically connected to the anode, the anode is configured in such a way that it acts as the first electrode of one of the first to fourth light-emitting elements, the first light-emitting element comprises a first EL layer and a second EL layer with an intermediate charge-generating layer, the second to fourth light-emitting elements comprise the first EL layer and the second EL layer with the charge-generating layer in between, the first EL layer contains a first light-emitting layer that emits blue light, and The second EL layer contains a second light-emitting layer that emits yellow light. [3] Light-emitting device with bottom-emission structure, comprising: a multitude of pixels, one of which comprises: a transistor over a substrate, wherein the transistor comprises: an oxide semiconductor layer over a first insulating layer; a gate electrode above the oxide semiconductor layer; a source electrode and a drain electrode, which is electrically connected to the oxide semiconductor layer; and a second insulating layer over the oxide semiconductor layer, the source electrode and the drain electrode; an anode across the transistor; a first EL layer configured to emit one selected of blue light and yellow light; a second EL layer configured to emit a different selection of blue and yellow light; and a charge generation layer between the first EL layer and the second EL layer, where: a first light-emitting element comprising the first EL layer, the charge-generating layer and the second EL layer, configured to emit light through a first color layer, such that blue light is extracted outwards from the light-emitting device; a second light-emitting element comprising the first EL layer, the charge-generating layer and the second EL layer, configured to emit light through a second color layer, such that green light is extracted outwards from the light-emitting device; a third light-emitting element comprising the first EL layer, the charge-generating layer and the second EL layer, configured to emit light through a third color layer, such that red light is extracted outwards from the light-emitting device; a fourth light-emitting element comprising the first EL layer, the charge-generating layer and the second EL layer, configured to emit light outwards from the light-emitting device; the light emitted outwards from the light-emitting device by the fourth light-emitting element is obtained by combining one selected from blue light and yellow light emitted by the first EL layer, and the other selected from blue light and yellow light emitted by the second EL layer; one of the source electrodes and the drain electrode is electrically connected to the anode; and the anode is configured to act as the first electrode of one of the first to fourth light-emitting elements. [4] Light-emitting device according to any one of claims 1 to 3, wherein: a peak wavelength of the blue light emitted by the first light-emitting element is 400 nm to 480 nm inclusive, a peak wavelength of the green light emitted by the second light-emitting element is 500 nm to 560 nm inclusive, a peak wavelength of the red light emitted by the third light-emitting element is 580 nm to 680 nm, and The first to fourth light-emitting elements overlap the transistor. [5] Light-emitting device according to any one of claims 1 to 3, wherein: the fourth light-emitting element is configured to emit yellow light, and The peak wavelength of the yellow light emitted by the fourth light-emitting element is 555 nm to 590 nm inclusive. [6] Light-emitting device according to claim 1, wherein the fluorescent substance has a pyrene framework with two benzo[b]naphtho[1,2-d]furanylamine frameworks. [7] Light-emitting device according to claim 2 or 3, wherein a fluorescent substance in the first EL layer comprises a pyrene framework with two benzo[b]naphtho[1,2-d]furanylamine frameworks. [8] Light-emitting device according to claim 6, wherein in the pyrene framework the two benzo[b]naphtho[1,2-d]furanylamine frameworks are bonded to the 1 and 6 positions. [9] Light-emitting device according to claim 7, wherein in the pyrene framework the two benzo[b]naphtho[1,2-d]furanylamine frameworks are bonded to the 1 and 6 positions. [10] Light-emitting device according to claim 1, wherein the fluorescent substance has an aromatic diamine skeleton or a pyrenediamine skeleton. [11] Light-emitting device according to claim 2, wherein the first EL layer comprises a fluorescent substance, and wherein the fluorescent substance has an aromatic diamine skeleton or a pyrenediamine skeleton. [12] Light-emitting device according to claim 3, wherein the first EL layer comprises a fluorescent substance, wherein the fluorescent substance has an aromatic diamine skeleton or a pyrenediamine skeleton, wherein the first to fourth light-emitting elements share a cathode, and wherein each of the first to fourth light-emitting elements further comprises a hole injection layer, a hole transport layer, an electron transport layer and an electron injection layer. [13] Light-emitting device according to any one of claims 1 to 3, wherein one of the first EL layer and the second EL layer comprises a first organic compound and a second organic compound, wherein the first organic compound and the second organic compound form an exciplex, wherein the first to fourth light-emitting elements share a cathode, and wherein each of the first to fourth light-emitting elements further comprises a hole injection layer, a hole transport layer, an electron transport layer and an electron injection layer.

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