lighting equipment

Abstract

To provide a luminaire using an electroluminescence material capable of performing color matching or lighting control by a simple method.SOLUTION: A luminaire includes a first light emitting element and a second light emitting element which exhibits a luminescent color having a longer wavelength than that of a luminescent color exhibited by the first light emitting element, and starts light emission with a lower voltage than that of the first light emitting element. By connecting the first light emitting element and the second light emitting element in parallel, the composite luminescent color of the luminescent color of the first light emitting element and the luminescent color of the second light emitting element is controlled by a voltage applied to the first light emitting element and the second light emitting element.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a lighting device including a light-emitting member that exhibits electroluminescence. [Background technology]

[0002] Based on calculations that the luminous efficiency is higher than that of incandescent bulbs and fluorescent lights, it is being considered as the next generation lighting device. Lighting devices equipped with light-emitting elements using electroluminescent materials are attracting attention. The luminescent material can be formed into a thin film with a thickness of 1 μm or less by methods such as vapor deposition and coating. The shape of the lighting device has also been designed in a unique way.

[0003] The color of light emitted from such a light-emitting element can be adjusted arbitrarily by appropriately selecting the materials used. For example, in Patent Document 1, a method is disclosed in which a plurality of light emitting elements are arranged in accordance with the respective light emission colors. The document discloses a lighting device that adjusts color temperature by applying individual voltages to light-emitting elements. do. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-317296 Summary of the Invention [Problem to be solved by the invention]

[0005] One aspect of the present invention is to provide a lighting device that can adjust the color or brightness in a simpler manner. This is one of the challenges. [Means for solving the problem]

[0006] In one aspect of the present invention, first and second light-emitting elements having different emission colors and light-emission starting voltages are connected in parallel. The lighting device controls the emitted color by applying a voltage to the first and second light-emitting elements. More specifically, for example, the following configuration can be adopted.

[0007] The lighting device according to one embodiment of the present invention includes a first light-emitting element and a second light-emitting element connected in parallel to the first light-emitting element. and a second light-emitting element, the second light-emitting element having a wavelength longer than the light color of the first light-emitting element. and starts emitting light at a voltage lower than that of the first light-emitting element. The light emitting color obtained by combining the light emitting color of the first light emitting element and the light emitting color of the second light emitting element is outputted from the first light emitting element and the second light emitting element. This is a lighting device that is controlled by applying voltage to a light element.

[0008] In addition, in the lighting device of one embodiment of the present invention, a first light-emitting element and a second light-emitting element connected in parallel to the first light-emitting element are and a second light-emitting element having a light emission color different from that of the first light-emitting element. The second light emitting element emits light of a long wavelength and starts emitting light at a voltage lower than that of the first light emitting element. The element emits light with a higher luminance than the first light-emitting element, and the light color of the first light-emitting element and the light color of the second light-emitting element are the same. The emission color obtained by combining the emission color of the first light-emitting element and the emission color of the second light-emitting element is obtained by adjusting the voltage applied to the first light-emitting element and the second light-emitting element. It is a lighting device controlled by pressure.

[0009] In the above lighting device, the first light-emitting element and the second light-emitting element are stacked. It may also be used.

[0010] In the above lighting device, the luminous color of the first light-emitting element and the luminous color of the second light-emitting element are Preferably, the colors are complementary to each other.

[0011] In the above lighting device, the first light emitting element emits light in the range of 450 nm to 510 nm. The second light emitting element has a peak in the optical spectrum, and the second light emitting element emits light in the range of 550 nm to 600 nm. It may have a spectral peak.

[0012] In this specification, the light emitting element has a luminance of 1 cd / m 2 When the light starts to flash at the brightness of The voltage applied at this time is called the light emission start voltage. [Effects of the Invention]

[0013] The lighting device according to one embodiment of the present invention can adjust color and light intensity by a simple method. Furthermore, the lighting device according to one embodiment of the present invention can emit light of different colors using the same light source. Therefore, it can be applied to a wide range of applications. [Brief explanation of the drawings]

[0014] [Figure 1] 1A and 1B illustrate a conceptual diagram and a configuration example of a lighting device of one embodiment of the present invention. [Figure 2] 1A and 1B illustrate light-emitting elements that can be used in a lighting device according to one embodiment of the present invention. [Figure 3] FIG. 1 illustrates a configuration example of a lighting device according to one embodiment of the present invention. [Figure 4] FIG. 1 illustrates a configuration example of a lighting device according to one embodiment of the present invention. [Figure 5] 1A and 1B are diagrams showing examples of arrangement of light-emitting elements. [Figure 6] 10A to 10C are diagrams showing application examples of a lighting device. [Figure 7] 10A to 10C are diagrams showing application examples of a lighting device. [Figure 8] 1A to 1C are diagrams illustrating light-emitting elements according to an embodiment. [Figure 9] 10A and 10B are graphs showing characteristics of light-emitting elements according to examples. [Figure 10] 6 is a calculation result showing the characteristics of the lighting device of the example. [Figure 11] 6 is a calculation result showing the characteristics of the lighting device of the example. DETAILED DESCRIPTION OF THE INVENTION

[0015] An example of an embodiment of the present invention will be described below with reference to the drawings. and the present invention is not limited to the above description, and may be modified in various forms and forms without departing from the spirit and scope of the present invention. It will be readily apparent to those skilled in the art that various modifications may be made to the details. It should not be construed as being limited to the description of the embodiments and examples shown below. In the embodiments and examples described below, the same parts or parts having similar functions are designated by the same reference numerals. The same reference numerals are used in common among different drawings, and repeated explanations thereof will be omitted.

[0016] In addition, the position, size, range, etc. of each component shown in the drawings are not necessarily the actual size for ease of understanding. Therefore, the disclosed invention may not necessarily represent the position, size, range, etc. Furthermore, the present invention is not limited to the position, size, range, etc. disclosed in the drawings, etc.

[0017] In this specification, ordinal numbers such as "first," "second," and "third" are used to avoid confusion of constituent elements. The numbers are added to avoid confusion and are not intended to limit the number.

[0018] (Embodiment 1) In this embodiment, one mode of a lighting device will be described with reference to FIGS.

[0019] FIG. 1A illustrates a conceptual diagram of a lighting device. The first light emitting element 100 and the second light emitting element 102 are arranged in a row. 00 and the second light emitting element 102 emit different light colors and have different light emission start voltages ( Hereinafter, in this embodiment, the second light-emitting element 10 2 emits light having a wavelength longer than that of the first light-emitting element 100, and The case where light emission starts at a voltage lower than that of the light emitting element 100 will be described as an example. One embodiment is not limited to this, and the first light-emitting element 100 may be configured to emit light in a manner similar to that of the second light-emitting element 102. The second light emitting element 102 emits light having a wavelength longer than the first light emitting element 102 and emits light at a voltage lower than that of the first light emitting element 102. You may begin.

[0020] The first light emitting element 100 and the second light emitting element 102 are connected in parallel and therefore have the same voltage. Here, the light emission start voltage (Vth _100 (Let us assume that is the light emission start voltage (Vth _102 Since it is higher than The applied voltage is Vth _102 More than Vth _100 If it is less than 1000, the second light-emitting element 10 Therefore, the color of the light emitted from the lighting device is determined by the color of the light emitted from the second light emitting element 102. It will be the same color as the light.

[0021] Also, the applied voltage is Vth _100 When the above is done, the second light emitting element 102 and the first light emitting element Light emission from the element 100 is obtained until the intensity of the light emission from the first light-emitting element 100 increases sufficiently. (For example, if the luminous emittance of the first light-emitting element 100 is 30000 lm / m 2 (until it reaches As the applied voltage increases, the ratio of the light emitted by the first light emitting element 100 to the total luminous flux increases. For example, when the luminous emittance of the first light-emitting element 100 is 30000 lm / m 2 to The voltage when it reaches Vf _100 Then, the applied voltage is Vth _100 More than Vf _1 00If the voltage is less than 100 V, the light emitted by the lighting device changes from the second light emitting element 102 to the first light emitting element 102 as the voltage increases. The light emitting color of the first light emitting element 100 and the light emitting color of the second light emitting element 102 are matched from the light emitting color of the first light emitting element 100 and the light emitting color of the second light emitting element 102. As the voltage increases, the first light emitting element 100 and the second light emitting element 110 gradually change to the color shown in FIG. The luminance of the light emitting element 102 also increases, and therefore the luminance of the entire lighting device also increases.

[0022] Also, the applied voltage is Vf _100 In the above cases, the light color of the lighting device is the same as that of the first light-emitting element. The color of the light emitted from the first light-emitting element 100 and the color of the light emitted from the second light-emitting element 102 are kept the same. This increase increases the luminous intensity of the entire lighting device.

[0023] In this way, by connecting light-emitting elements with different emission colors and emission start voltages in parallel, The color and brightness of the lighting device can be adjusted by controlling only the applied voltage without using any other means. In addition, since the color and brightness can be adjusted by a simple method, it is possible to This can increase convenience.

[0024] The first light emitting element 100 and the second light emitting element 102 emit light in complementary colors. For example, the first light emitting element 100 may be configured to emit blue to blue-green light (450nm). The element is an element that emits light having a peak in the emission spectrum of 510 nm or more, The light emitting element 102 emits yellow to orange light (emission spectrum of 550 nm to 600 nm). Assuming that the first light emitting element 100 is an element that exhibits a light emission having a peak, the light emission starting voltage of the first light emitting element 100 is When a lower voltage is applied, the lighting device emits orange light, and when the applied voltage is increased, As the temperature rises, the light color of the lighting fixture can be adjusted from warm white to warm white to white to daylight white. do.

[0025] In addition, when the first light emitting element 100 and the second light emitting element 102 have approximately the same area, , when the first light-emitting element 100 starts to emit light (i.e., the first light-emitting element 100 and The light emitting element 102 of _100 When the second light-emitting element 102 is applied with Emissivity is 30,000lm / m 2 In this case, the light emitting element 100 emits light with respect to the total luminous flux. Since the proportion of light is small, the applied voltage is Vth _100 More than Vf _100 Even if it is less than The color of the light emitted from the entire lighting device is unlikely to change. _100 When applying , the luminous emittance of the second light-emitting element 102 is 300 lm / m 2 If it is less than Since the proportion of light emitted by the second light emitting element 102 is small, it is difficult to modulate the color of light emitted by the lighting device. Therefore, when the first light emitting element 100 and the second light emitting element 102 have approximately the same area, In this case, the first light emitting element 100 and the second light emitting element 102 have a Vth _100 When is applied The luminous emittance of the second light-emitting element 102 is 300 lm / m 2 More than 30000lm / m 2 Not yet It is preferable that the luminous emittance is less than 300 lm / m. 2 More than 30000lm / m 2 Less than means that the luminance of a surface light source assuming a perfectly diffusing surface is approximately 10 cd / m 2 End 10000cd / m 2 Equivalent to less than.

[0026] In addition, the second light emitting element 102 preferably emits light with higher brightness than the first light emitting element 100. The second light emitting element 102 emits light with a longer wavelength than the first light emitting element 100. The light emitted from the second light emitting element 102 has a higher visibility than the light emitted from the first light emitting element 100. Therefore, when the second light emitting element 102 emits light with high luminosity, the wavelength range with high visibility can be effectively illuminated. This can be utilized to improve the power efficiency of the lighting device.

[0027] In addition, light-emitting elements that can be applied to lighting devices include those that use electroluminescence ( Elements that utilize the LED (Light Emitting Diode) effect can be used. Emitting Diode), an element that exhibits organic EL light emission (organic EL element), For the organic light emitting diode, an element that exhibits inorganic EL light emission (inorganic EL element) can be used. EL elements have gentle diode characteristics, so they emit light at a slower rate than LEDs. There is a range of voltages required to reach sufficient luminous flux. Therefore, the dimmable voltage range of the lighting device is In addition, organic EL elements generate less heat than LEDs. Because it is small, organic resin, which is lightweight but vulnerable to heat, can be used for the housing of the lighting device. This allows the lighting device to be made lighter.

[0028] 1(B) and 1(C) show examples of the configuration of the lighting device. 1(C) is a cross-sectional view taken along line A1-A2 in FIG. 1(B). 1(C) is sealed by a first housing 230 and a second housing 232. A first light emitting element 100 and a second light emitting element 102 are disposed in the defined space. The light emitting surfaces of the first light emitting element 100 and the second light emitting element 102 are arranged side by side on the same plane. It is being done.

[0029] The first light emitting element 100 and the second light emitting element 102 are each formed of a pair of electrodes and a light emitting element disposed between the pair of electrodes. The light emitted from the EL layer passes through the first housing 230 and is emitted to the outside. Therefore, the first housing 230 accommodates at least the first light-emitting element 100 and the second light-emitting element 101. It has a translucency that allows light from 102 to pass through.

[0030] The shape of the light emitting surface of the first light emitting element 100 or the second light emitting element 102 is a square. In addition to the polygonal shape, it may be a circle, and the housing (first housing 230) covering the radiation surface The shape of the radiation surface may also be made to correspond to the shape of the radiation surface.

[0031] In FIG. 1B and FIG. 1C, the first housing 230 includes the first light-emitting element 100 and However, it also functions as a support member for the first light emitting element 100 or the second light emitting element 102. The second light emitting element 102 is formed on a support member separate from the first housing 230, and the support member can be disposed on the first housing 230. Also, the first light-emitting element 100 and the second The light emitting elements 102 may be formed on the same support member or on separate support members. is also good.

[0032] Specific examples of materials used for the first housing 230 include plastic (organic resin), glass, Alternatively, quartz or the like can be used. As the plastic, for example, polycarbonate can be used. Examples of the material include materials made of polyethylene terephthalate, polyarylate, polyethersulfone, etc. If plastic is used for the housing 230, the weight of the lighting device can be reduced. Therefore, it is preferable.

[0033] The second housing 232 can be made of the same material as the first housing 230. In order to reduce the weight, it is preferable to use plastic for the second housing 232. The second housing 232 does not need to be transparent, so the second housing 232 can be made of a metal material. It is also possible to use a material made of a metal member (hereinafter referred to as a metal member). There is no particular limitation on the material, but metals such as aluminum, copper, nickel, etc., A metal alloy such as aluminum alloy or stainless steel can be preferably used. There is no particular limitation on the thickness of the metal member, but for example, a thickness of 10 μm or more and 200 μm or less is used. This is preferable because it allows the weight of the lighting device to be reduced. By using a metal member as 232, the first light emitting element 100 and the second light emitting element 102 Therefore, deterioration caused by moisture can be suppressed. It is possible to provide a highly efficient lighting device.

[0034] The first housing 230 and the second housing 232 are bonded together by an adhesive layer (not shown). The adhesive layer may be a visible light curing, ultraviolet curing, or heat curing adhesive. The adhesive material can be, for example, epoxy resin, acrylic resin, Examples of such adhesives include acrylic resin and phenolic resin. The first housing 230, the adhesive layer, and the second housing 232 may contain a water substance. Using the same organic resin material improves the adhesion between the first housing 230 and the second housing 232. However, the adhesive layer is not necessarily provided. The first housing 230 and the second housing 232 are made of thermoplastic organic resin, and are bonded together by thermocompression. The first housing 230 and the second housing 232 may be glued together.

[0035] The sizes of the first housing 230 and the second housing 232 may be appropriately determined depending on the application of the lighting device. For example, the diameter can be set to 10 cm to 14 cm, preferably 12 cm. It can be a disk shape of 1 / 2 inch or a square with a 5-inch side.

[0036] In addition, in the space inside the housing in which the first light emitting element 100 and the second light emitting element 102 are provided, A water-absorbing substance may be provided as a desiccant. The water-absorbing substance may be disposed in a solid state such as powder. The first light emitting element 100 and the second light emitting element 110 are formed in the form of a film containing a water absorbing substance by a film forming method such as sputtering. and the second light emitting element 102. The space inside the housing may be filled with epoxy resin. Alternatively, the sealing may be performed with a resin such as an acrylic resin, a silicone resin, or a phenolic resin.

[0037] In addition, the upper surfaces of the first light emitting element 100 and the second light emitting element 102 or the inner wall of the housing are covered with The inorganic insulating film may be provided to protect the substrate from external contaminants such as water. By providing an inorganic insulating film, deterioration of the light-emitting element is reduced and the light is The durability and life of the lighting device can be improved.

[0038] As the inorganic insulating film, a single layer or a laminated layer of a nitride film and a nitride oxide film can be used. In general, silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, oxide It is formed by CVD method, sputtering method, etc. using aluminum nitride etc. according to the material. Preferably, it is formed by the CVD method using silicon nitride. The thickness of the insulating film may be about 100 nm or more and 1 μm or less. Aluminum oxide film, diamond-like carbon (DLC) film, nitrogen-containing carbon film, sulfide film A film containing lead and silicon oxide (ZnS·SiO2 film) may also be used.

[0039] The lighting device shown in FIG. 1B and FIG. 1C includes a first light-emitting element 100 and a second light-emitting element 110. 02, the light emitting surfaces are arranged side by side on the same plane, It is possible to suppress the decrease in the efficiency. The light scattering agent is applied to the radiation surface of the housing 230, or an optical element such as a diffusion film is applied to the radiation surface side. The light extraction efficiency of the lighting device may be improved by disposing a film or the like. The light extraction efficiency can also be improved by providing a diffraction grating on the light emitting surface of the first housing 230. In particular, the first light emitting element 100 and the second light emitting element 102 can When the emitting surfaces are arranged side by side on the same plane, the diffraction grating is aligned to the emission wavelength of each light-emitting element. This is effective because it can be designed to suit the needs of the customer.

[0040] FIG. 2 shows a specific example of the configuration of the first light-emitting element 100 or the second light-emitting element 102. The light-emitting element shown in FIG. 2(A) includes a first electrode 104 and an EL layer 106 formed on the first electrode 104. A second electrode 108 is provided on the EL layer 106 .

[0041] The first electrode 104 is disposed in contact with the first housing 230 and is a light emitting element when viewed from the EL layer 106. Therefore, the light-transmitting material is used. The materials used are indium oxide, indium tin oxide, indium zinc oxide, and oxide. Zinc oxide, zinc oxide doped with gallium, graphene, etc. can be used.

[0042] The first electrode 104 may be made of gold, platinum, nickel, tungsten, chromium, or molybdenum. Metallic materials such as nickel, iron, cobalt, copper, palladium, or titanium can be used. Alternatively, nitrides of these metal materials (for example, titanium nitride) may be used. When using a material (or its nitride), it is sufficient to thin it so that it has light-transmitting properties.

[0043] An EL layer 106 is provided on the first electrode 104. The EL layer 106 includes at least It is sufficient if the light-emitting layer contains a light-emitting organic compound. a layer containing a substance with high hole transporting properties; a layer containing a substance with high electron injecting properties; a layer containing a substance with high electron transporting and hole transporting properties, and a layer containing a bipolar substance (a substance with high electron transporting and hole transporting properties) In this embodiment, a layer containing the above-mentioned metal oxide can be appropriately combined to form a laminate structure. The EL layer 106 is made up of a hole injection layer 701, a hole transport layer 702, and a light emitting layer 703 from the first electrode 104 side. A layer 703, an electron transport layer 704, and an electron injection layer 705 are stacked in this order.

[0044] The hole-injection layer 701 is a layer containing a substance with a high hole-injection property. Examples of the oxides include molybdenum oxide, titanium oxide, vanadium oxide, rhenium oxide, Ruthenium oxide, chromium oxide, zirconium oxide, hafnium oxide, tantalic acid Metal oxides such as tungsten oxide, silver oxide, tungsten oxide, and manganese oxide can be used. In addition, phthalocyanine (abbreviation: H2Pc), copper (II) phthalocyanine (abbreviation: C Phthalocyanine compounds such as phthalocyanine (Pc) can be used.

[0045] In addition, the low molecular weight organic compound 4,4',4''-tris(N,N-diphenylamino) ) triphenylamine (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl) (N-phenylamino)triphenylamine (abbreviation: MTDATA), 4 ,4'-Bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl DPAB, 4,4'-bis(N-{4-[N'-(3-methylphenyl)- N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviated as DNTP D), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino] 3-[N-(9-phenylcarbazol-3-yl)benzene (abbreviation: DPA3B) )-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3, 6-Bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9- Phenylcarbazole (abbreviation: PCzPCA2), 3-[N-(1-naphthyl)-N-( 9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: P Aromatic amine compounds such as CzPCN1) can be used.

[0046] Furthermore, polymeric compounds (oligomers, dendrimers, polymers, etc.) can also be used. For example, poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriflate) Phenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenyl (N'-phenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide (abbreviation: PTPDMA), poly[N,N'-bis(4-butylphenyl)-N,N'-bi Examples include polymer compounds such as [poly(phenyl)benzidine] (abbreviation: Poly-TPD). In addition, poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (PEDOT / PSS), polyaniline / poly(styrene sulfonate) (PAni / PS A polymer compound to which an acid such as methyl methyl stearate (S) is added can be used.

[0047] In particular, the hole injection layer 701 is formed by using an organic compound having a high hole transporting property and containing an acceptor substance. It is preferable to use a composite material having a high hole transporting property and an acceptor property. By using a composite material containing These composite materials have high hole transport properties and can reduce the driving voltage of the light-emitting element. The composite material can be formed by co-evaporating a non-reactive material and an acceptor material. By forming the hole injection layer 701 using This makes it easier to inject holes.

[0048] The organic compounds used in the composite materials include aromatic amine compounds, carbazole derivatives, aromatic Various compounds such as aromatic hydrocarbons and polymer compounds (oligomers, dendrimers, polymers, etc.) As the organic compound used for the composite material, a compound having a high hole transporting property can be used. It is preferable that the organic compound is a low-molecular-weight organic compound. -6 cm 2 Hole transfer above / Vs However, it is preferable that the material has a higher hole transporting property than the electron transporting property. In the following, organic compounds that can be used in composite materials will be described. The compounds are specifically listed below.

[0049] Examples of organic compounds that can be used in composite materials include TDATA and MTDATA. , DPAB, DNTPD, DPA3B, PCzPCA1, PCzPCA2, PCzPCN 1,4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD), N,N'-bis(3-methylphenyl)-N,N'-diphenyl 4-phenyl-[1,1'-biphenyl]-4,4'-diamine (TPD) 4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) ) and other aromatic amine compounds, such as 4,4'-di(N-carbazolyl)biphenyl (abbreviation: C BP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: T CPB), 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazo CzPA, 9-phenyl-3-[4-(10-phenyl-9-anthryl )phenyl]-9H-carbazole (abbreviation: PCzPA), 1,4-bis[4-(N-carbazole) Carbazole derivatives such as [(carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene A conductor may be used.

[0050] In addition, 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t- BuDNA), 2-tert-butyl-9,10-di(1-naphthyl)anthracene, 9 ,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 2-t ert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviation: tB uDBA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 9,10- Diphenylanthracene (abbreviation: DPAnth), 2-tert-butylanthracene ( Abbreviation: t-BuAnth), 9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviation: DMNA), 9,10-bis[2-(1-naphthyl)phenyl]-2-tert -butylanthracene, 9,10-bis[2-(1-naphthyl)phenyl]anthracene , 2,3,6,7-tetramethyl-9,10-di(1-naphthyl)anthracene, and other aromatic compounds Aromatic hydrocarbon compounds can be used.

[0051] Furthermore, 2,3,6,7-tetramethyl-9,10-di(2-naphthyl)anthracene, 9,9'-bianthryl, 10,10'-diphenyl-9,9'-bianthryl, 10, 10'-bis(2-phenylphenyl)-9,9'-bianthryl, 10,10'-bis [(2,3,4,5,6-pentaphenyl)phenyl]-9,9'-bianthryl, Thracene, tetracene, rubrene, perylene, 2,5,8,11-tetra(tert-buthylene) (ethyl)perylene, pentacene, coronene, 4,4'-bis(2,2-diphenylvinyl) Biphenyl (abbreviation: DPVBi), 9,10-bis[4-(2,2-diphenylvinyl) Aromatic hydrocarbon compounds such as diphenylanthracene (abbreviation: DPVPA) can be used. can.

[0052] The electron acceptor is 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroethylene. Organic compounds such as fluoroquinodimethane (abbreviated as F4-TCNQ) and chloranil, and transition metals In addition, metal oxides belonging to groups 4 to 8 of the periodic table can be used. Specifically, vanadium oxide, niobium oxide, tantalum oxide, Chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide are electrically Among them, molybdenum oxide is particularly stable in the atmosphere and has a high molecular acceptability. It is preferred because it has low moisture content and is easy to handle.

[0053] In addition, the above-mentioned polymer compounds such as PVK, PVTPA, PTPDMA, and Poly-TPD A composite material may be formed using the above-described electron acceptor and used for the hole-injection layer 701.

[0054] The hole transport layer 702 is a layer containing a substance with a high hole transport property. Examples of suitable bis[N-(9,9-dimethylphenyl)-4,4'-bis( ... [difluoroen-2-yl]-N-phenylamino]biphenyl (abbreviation: DFLDPBi) , 4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenyl An aromatic amine compound such as bis(amino)biphenyl (abbreviation: BSPB) can be used. The substances mentioned here are mainly 10 -6 cm 2 It is a material with a hole mobility of 1 / Vs or more. However, other substances may be used as long as they have a higher hole transporting property than electron transporting property. The layer containing a substance having a high hole-transporting property is not limited to a single layer, and may be a layer containing the above substance. Two or more layers may be laminated.

[0055] The hole transport layer 702 may also contain carbazole derivatives such as CBP, CzPA, and PCzPA. Anthracene derivatives such as t-BuDNA, DNA, and DPAnth may also be used. stomach.

[0056] The hole transport layer 702 may be made of a material such as PVK, PVTPA, PTPDMA, or Poly-TPD. Any polymeric compound can be used.

[0057] The light-emitting layer 703 is a layer containing a light-emitting organic compound. For example, a fluorescent compound that emits fluorescence or a phosphorescent compound that emits phosphorescence can be used. .

[0058] Examples of fluorescent compounds that can be used in the light-emitting layer 703 include blue light-emitting materials and and N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'- Diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carba 4'-(10-phenyl-9-anthryl)triphenylamine ( Abbreviation: YGAPA), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl -9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA) In addition, N-(9,10-diphenyl-2-anthracene) is used as a green emitting material. (phenyl)-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,9 -diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABPhA), N-(9 ,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenyl Nylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(1,1'-biphenyl)] -2-yl)-2-anthryl]-N,N',N'-triphenyl-1,4-phenylene Diamine (abbreviation: 2DPABPhA), N-[9,10-bis(1,1'-biphenyl- 2-yl)]-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenyl Anthracene-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylamine tetrathane-9-amine (abbreviated as DPhAPhA) and other compounds. Materials: rubrene, 5,12-bis(1,1'-biphenyl-4-yl)-6,11 -diphenyltetracene (abbreviation: BPT) and other red emitting materials. N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11- Diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetramethyl Rachis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-di amine (abbreviation: p-mPhAFD) and others.

[0059] Furthermore, examples of phosphorescent compounds that can be used in the light-emitting layer 703 include blue-based emitting compounds. The material was bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ] Iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis [2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ]Iridium (II I) Picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis(trifluoromethyl)methyl] (trimethyl)phenyl]pyridinato-N,C 2’}Iridium(III) picolinate (abbreviation Name: Ir(CF3ppy)2(pic)), bis[2-(4',6'-difluorophenyl) (I)pyridinato-N,C 2’ ]Iridium(III) acetylacetonate (abbreviation: FI r(acac)) and the like. In addition, tris(2-phenanthroline) is a green emitting material. Nylpyridinato-N,C 2’ ) Iridium(III) (abbreviation: Ir(ppy)3), bis (2-phenylpyridinato-N,C2’ ) Iridium(III) acetylacetonate ( Abbreviation: Ir(ppy)2(acac)), bis(1,2-diphenyl-1H-benzoimide) Iridium(III) acetylacetonate (abbreviation: Ir(pbi)2(ac ac)), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: Ir(bzq)2(acac)), tris(benzo[h]quinolinato)iridium In addition, yellow luminescent materials such as Ir(bzq)3 are also available. Bis(2,4-diphenyl-1,3-oxazolato-N,C 2’ ) Iridium (I II) Acetylacetonate (abbreviation: Ir(dpo)2(acac)), bis[2-(4 '-Perfluorophenylphenyl)pyridinato]iridium(III) acetylacetonate nate (abbreviation: Ir(p-PF-ph)2(acac)), bis(2-phenylbenzothiazol-1-yl) Azorato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(bt )2(acac)), (acetylacetonato)bis[2,3-bis(4-fluorophenyl) Ir(Fdppr-Me)-5-methylpyrazinatoiridium(III) 2(acac)), (acetylacetonato)bis{2-(4-methoxyphenyl)-3, 5-Dimethylpyrazinate}iridium(III) (abbreviation: Ir(dmmoppr)2(a cac)) and the like. In addition, tris(2-phenylquinazolidinyl) is an orange-emitting material. Norinato-N,C 2’ ) Iridium(III) (abbreviation: Ir(pq)3), bis(2-fluoromethyl) Phenylquinolinato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: I r(pq)2(acac)), (acetylacetonato)bis(3,5-dimethyl-2-furan (phenylpyrazinate)iridium(III) (abbreviation: Ir(mppr-Me)2(acac )), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrrolidone) iridium(III) (abbreviation: Ir(mppr-iPr)2(acac)), etc. In addition, bis[2-(2'-benzo[4,5-α ]thienyl)pyridinato-N,C 3’ ] Iridium (III) acetylacetonate (abbreviation Name: 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)), (acetylacetonate Nato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: Ir (tppr)2(acac)), (dipivaloylmethanato)bis(2,3,5-triphenylphosphine) Nilpyrazinato)iridium(III) (abbreviation: Ir(tppr)2(dpm)), 2, 3,7,8,12,13,17,18-Octaethyl-21H,23H-porphyrin White Organometallic complexes such as gold(II) (abbreviation: PtOEP) are also available. tetrahydrofuran(III) acetone (monophenanthroline) terbium(III) (abbreviation: Tb(acac )3(Phen)), tris(1,3-diphenyl-1,3-propanedionato)(mono Phenanthroline) europium(III) (abbreviation: Eu(DBM)3(Phen)), Tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthate) rare earths such as Eu(TTA)3(Phen) Metal complexes emit light from rare earth metal ions (electron transition between different multiplicities), so phosphorus It can be used as a photoactive compound.

[0060] The light-emitting layer 703 may be formed by dissolving the above-described light-emitting organic compound (guest material) in another material ( The host material may be dispersed in a variety of materials. It has a higher lowest unoccupied molecular orbital (LUMO) level than luminescent materials and a higher highest occupied molecular orbital (HOL) level. It is preferable to use a substance with a low HOMO level.

[0061] Specifically, the host material is tris(8-quinolinolato)aluminum(III). (abbreviation: Alq), tris(4-methyl-8-quinolinolato)aluminum(III) ( Abbreviation: Almq3), bis(10-hydroxybenzo[h]quinolinato)beryllium (I I) (abbreviation: BeBq2), bis(2-methyl-8-quinolinolato)(4-phenylphenyl) bis(8-quinolinolato)aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc ( II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolato]zinc (I I) (abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenolato]zinc (I I) (abbreviation: ZnBTZ), metal complexes such as 2-(4-biphenylyl)-5-(4-te rt-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-biphenyl bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl ]benzene (abbreviation: OXD-7), 3-(4-biphenylyl)-4-phenyl-5-(4 -tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 2,2' ,2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) dazole (abbreviated as TPBI), bathophenanthroline (abbreviated as BPhen), Heterocyclic compounds such as proine (abbreviated as BCP) and 9-[4-(10-phenyl-9-azathioprine) 3,6-diphenyl- 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation :DPCzPA), 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation :DPPA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 2-te rt-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 9,9'-Bianthryl (abbreviation: BANT), 9,9'-(stilbene-3,3'-diyl) Diphenanthrene (DPNS), 9,9'-(stilbene-4,4'-diyl) ) Diphenanthrene (abbreviation: DPNS2), 3,3',3''-(benzene-1,3,5 -triyl)tripylene (abbreviation: TPB3), 9,10-diphenylanthracene (abbreviation: :DPAnth), condensed aromatic compounds such as 6,12-dimethoxy-5,11-diphenylchrysene Aromatic compounds, N,N-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl] 4-(10-phenyl)-9H-carbazol-3-amine (abbreviation: CzA1PA), N,9-diphenyl-9-anthryl)triphenylamine (abbreviation: DPhPA), N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole-3- Amine (abbreviation: PCAPA), N,9-diphenyl-N-{4-[4-(10-phenyl -9-anthryl)phenyl]phenyl}-9H-carbazol-3-amine (abbreviation: P CAPBA), N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl- 9H-Carbazol-3-amine (abbreviation: 2PCAPA), NPB (or α-NPD) Aromatic amine compounds such as TPD, DFLDPBi, and BSPB can be used. do.

[0062] In addition, multiple host materials can be used. For example, A substance that suppresses crystallization, such as amine, may be further added. To make the transfer more efficient, NPB, Alq, or the like may be further added.

[0063] By dispersing the guest material in the host material, crystallization of the light-emitting layer 703 is suppressed. In addition, it is possible to suppress concentration quenching due to a high concentration of the guest material. can be done.

[0064] Furthermore, a polymer compound can be used for the light-emitting layer 703. Specifically, a blue-based light-emitting As an optical material, poly(9,9-dioctylfluorene-2,7-diyl) (abbreviation: PFO ), poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,5-dimethicone] oxybenzene-1,4-diyl)] (abbreviation: PF-DMOP), poly{(9,9-di- N,N'-di-(p-butylphenyl)-co-[N,N'-octylfluorene-2,7-diyl] -1,4-diaminobenzene]} (abbreviation: TAB-PFH). As color-emitting materials, poly(p-phenylene vinylene) (abbreviation: PPV), poly[(9 ,9-dihexylfluorene-2,7-diyl)-alt-co-(benzo[2,1,3 ]thiadiazole-4,7-diyl)] (abbreviation: PFBT), poly[(9,9-dioctyl Fluorenylene-2,7-divinylene)-alt-co-(2-methoxy-5-(2- ethylhexyloxy-1,4-phenylene). Orange to red As a light-emitting material, poly[2-methoxy-5-(2'-ethylhexoxy)-1,4-fluorophenyl] phenylenevinylene] (abbreviation: MEH-PPV), poly(3-butylthiophene-2,5- diyl) (abbreviation: R4-PAT), poly{[9,9-dihexyl-2,7-bis(1-silyl) 2,5-bis(N,N'-diphenyl)-alt-co-[2,5-bis(N,N'-diphenyl) poly{[2-methoxy-5-(2-ethylhexylamino)-1,4-phenylene]}, hydroxy)-1,4-bis(1-cyanovinylenephenylene)]-alt-co-[2,5 -bis(N,N'-diphenylamino)-1,4-phenylene]}(abbreviation: CN-PPV -DPD) etc.

[0065] The light-emitting layer may have a laminated structure of two or more layers.

[0066] In this embodiment, the first light emitting element 100 and the second light emitting element 102 have different light emitting properties. Therefore, among the above-mentioned materials, light-emitting materials with different luminescent colors are used. The material is appropriately selected and used for the light-emitting layer of the first light-emitting element 100 and the light-emitting layer of the second light-emitting element 102. That's good enough.

[0067] The lighting device of this embodiment is configured to combine light emitted from a first light emitting element 100 and light emitted from a second light emitting element 102. The color of light emitted from the first and second light-emitting elements is controlled by applying a voltage to the first and second light-emitting elements. The color of the light emitted from the first light-emitting element 100 and the color of the light emitted from the second light-emitting element 101 are controlled to a desired color. By making the color of light emitted from the light emitting element 102 complementary to the color of light emitted from the light emitting element 102, white light can be emitted from the lighting device. The complementary colors are blue and yellow, or blue-green. For example, the first light emitting element 100 may be configured to emit light in the blue to blue-green wavelength range. The second light emitting element 102 is an element that emits light in the yellow to orange wavelength range. By connecting these in parallel, the light emitted can range from orange to daylight white by controlling the voltage. A lighting device can be obtained.

[0068] The yellow to orange wavelength range (560 nm or more and less than 580 nm) is a wavelength range with high visual sensitivity. Therefore, an EL layer having an emission layer whose emission spectrum peak is in the yellow to orange wavelength region is used. It is useful to apply this to the second light emitting element 102. The peak of the emission spectrum is yellow to orange. By using an EL layer in the color wavelength range, it is possible to utilize the wavelength range with high visibility. This can improve the power efficiency of the entire lighting device. It is possible.

[0069] As a luminescent substance having a peak in the yellow to orange wavelength region, for example, a pyrazine derivative is used. In addition, it is possible to use an organometallic complex as a ligand. The light-emitting layer can also be formed by dispersing the yellow dye in a host material. As a light-emitting substance having a peak in the wavelength region of red to orange, a phosphorescent compound can be used. The use of phosphorescent compounds results in higher power efficiency than fluorescent compounds. The organometallic complexes with the pyrazine derivatives as ligands can be It is a phosphorescent compound, has high luminous efficiency, and is easy to emit light in the yellow to orange wavelength range. It is suitable.

[0070] Furthermore, examples of luminescent substances with a peak in the blue wavelength region include pyrenediamine derivatives. As the luminescent substance having a peak in the blue wavelength region, fluorescent By using a fluorescent compound, it is possible to use a phosphorescent compound. The pyrene diamine derivative can provide a light-emitting element having a longer life than when the pyrene diamine derivative is used. is a fluorescent compound that has an extremely high quantum yield and a long life, making it suitable. be.

[0071] The electron-transporting layer 704 is a layer containing a substance with a high electron-transporting property. Examples of suitable aluminum compounds include tris(8-quinolinolato)aluminum (Alq), tris(4 -methyl-8-quinolinolato)aluminum (abbreviation: Almq3), bis(10-hydrogen Bis(2-methyl-8-hydroxybenzo[h]quinolinato)beryllium (BeBq2) -quinolinolato)(4-phenylphenolato)aluminum (abbreviation: BAlq), Metal complexes having a benzoquinoline skeleton or a benzoquinoline skeleton are also included. [2-(2-hydroxyphenyl)benzoxazolato]zinc (abbreviation: Zn(BOX)2 ), bis[2-(2-hydroxyphenyl)benzothiazolato]zinc (abbreviation: Zn(BT Metal complexes having oxazole-based or thiazole-based ligands such as Z)2) can also be used. In addition to metal complexes, 2-(4-biphenylyl)-5-(4-tert -butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD) and 1,3-bis [5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl] Benzene (abbreviation: OXD-7), 3-(4-biphenylyl)-4-phenyl-5-(4- tert-Butylphenyl)-1,2,4-triazole (abbreviation: TAZ), Vasofena Also use antihistamines such as BPhen and vasocuproine (BCP). The substances mentioned here are mainly 10 -6 cm 2 / Vs or higher electron mobility The electron transport layer is not limited to a single layer, but may be composed of two or more layers of the above-mentioned material. It may also be a laminate.

[0072] The electron injection layer 705 is a layer containing a substance with a high electron injection property. lithium, cesium, calcium, lithium fluoride, cesium fluoride, calcium fluoride, Alkali metals, alkaline earth metals, or compounds thereof, such as lithium oxide, are used. Also, rare earth metal compounds such as erbium fluoride can be used. In addition, the above-described substance for forming the electron transporting layer 704 can also be used.

[0073] The hole injection layer 701, the hole transport layer 702, the light emitting layer 703, and the electron transport layer 704 The electron injection layer 705 is formed by a deposition method (including a vacuum deposition method), an ink jet method, a coating method, respectively. It can be formed by a method such as a fabric method.

[0074] As shown in FIG. 2B, the EL layer is formed between the first electrode 104 and the second electrode 108. Hole injection layer 701, hole transport layer 702, light emitting layer 703, electron transport layer 704, electron injection buffer a heat transfer layer 706, an electronic relay layer 707, and a composite material layer 708 in contact with the second electrode 108. It may have.

[0075] By providing the composite material layer 708 in contact with the second electrode 108, it is possible to form a thin film by using a sputtering method in particular. Therefore, when the second electrode 108 is formed, damage to the EL layer 106 can be reduced. The composite material layer 708 is preferably formed using the above-described organic compound having a high hole transporting property. Composite materials containing acceptor substances can be used.

[0076] Furthermore, by providing an electron injection buffer layer 706, the composite material layer 708 and the electron transport layer 7 Since the injection barrier between the composite material layer 708 and the electrode 704 can be reduced, the electrons generated in the composite material layer 708 can be injected into the electrode 704. The electron transport layer 704 can be easily injected.

[0077] The electron injection buffer layer 706 contains an alkali metal, an alkaline earth metal, a rare earth metal, and and their compounds (alkali metal compounds (oxides such as lithium oxide, halides, carbonates) Alkaline earth metal compounds (including carbonates such as lithium and cesium carbonate), oxides, halides compounds of rare earth metals (including oxides, halides, carbonates) or rare earth metal compounds (including oxides, halides, carbonates) It is possible to use a substance with high electron injection properties, such as tetrahydrofuran (Tetrahydrofuran) and tetrahydrofuran (Tetrahydrofuran).

[0078] The electron-injecting buffer layer 706 is formed by containing a substance with high electron transporting properties and a donor substance. When the compound is formed, the mass ratio to the substance having high electron transport properties is 0.001 or more and 0.1 or less It is preferable to add the donor substance in the ratio of Alkali metals, alkaline earth metals, rare earth metals, and their compounds (alkali metal compounds ( Contains oxides such as lithium oxide, halides, and carbonates such as lithium carbonate and cesium carbonate ), alkaline earth metal compounds (including oxides, halides, and carbonates), or rare earth metals In addition to compounds of the group (including oxides, halides, and carbonates), tetrathianaphthacene (abbreviated Organic compounds such as TTN, nickelocene, and decamethylnickelocene can also be used. Note that the substance with a high electron transporting property can be the same as the material of the electron transporting layer 704 described above. The various materials can be used to form the substrate.

[0079] Furthermore, an electron relay layer 707 is formed between the electron injection buffer layer 706 and the composite material layer 708. The electron relay layer 707 is not necessarily provided, but it is preferable to form the electron relay layer 707. By providing the electron relay layer 707 with high transportability, electrons can be transferred to the electron injection buffer layer 706. It will be possible to send it quickly.

[0080] An electron relay layer 707 is sandwiched between the composite material layer 708 and the electron injection buffer layer 706. The structure is composed of an acceptor material contained in a composite material layer 708 and an electron injection buffer layer 70 The structure is such that it is difficult for the donor substance contained in 6 to interact with each other and inhibit each other's functions. Therefore, an increase in the driving voltage can be prevented.

[0081] The electron relay layer 707 contains a substance with high electron transport properties, and the LUM of the substance with high electron transport properties The O level is determined by the LUMO level of the acceptor material contained in the composite material layer 708 and the electron transport The layer 704 is formed so as to have a LUMO level between that of the highly electron-transporting substance contained in the layer 704 . In addition, when the electron relay layer 707 contains a donor material, the donor phase of the donor material The LUMO level of the acceptor material in the composite material layer 708 and the LUMO level of the electron transport layer 704 The LUMO level of the material with high electron transport properties is set to be between the specific energy The energy level of the material with high electron transport properties contained in the electron relay layer 707 is The MO level is set to -5.0 eV or more, preferably -5.0 eV or more and -3.0 eV or less. stomach.

[0082] The electron relay layer 707 contains a material with high electron transport properties, such as a phthalocyanine-based material. It is preferable to use a metal complex having a metal-oxygen bond and an aromatic ligand.

[0083] The phthalocyanine-based material contained in the electron relay layer 707 is specifically CuPc, S nPc (Phthalocyanine tin(II) complex), ZnPc (Phthalocyanine zinc complex), CoPc (Cobal t(II)phthalocyanine, β-form), FePc(Phthal ocyanine Iron) and PhO-VOPc(Vanadyl 2,9,16, 23-tetraphenoxy-29H,31H-phthalocyanine) It is preferable to use either one.

[0084] The metal complexes having a metal-oxygen bond and an aromatic ligand contained in the electron relay layer 707 include: It is preferable to use a metal complex having a metal-oxygen double bond. In this case, the molecule has acceptor properties (the ability to easily accept electrons), which facilitates electron transfer (donation and receipt). Furthermore, metal complexes with a metal-oxygen double bond are stable. By using a metal complex having a metal-oxygen double bond, it is possible to realize a light-emitting element at a low voltage and more safely. This makes it possible to drive the motor constantly.

[0085] As a metal complex having a metal-oxygen bond and an aromatic ligand, a phthalocyanine-based material is preferred. Specifically, VOPc (vanadyl phthalocyanine), SnO Pc(Phthalocyanine tin(IV) oxide complex) and TiOPc (Phthalocyanine titanium oxide co complex) is a molecule in which the metal-oxygen double bond acts on other molecules. This is preferred because it is easy to do and has high acceptor properties.

[0086] The above-mentioned phthalocyanine-based material preferably has a phenoxy group. Specifically, a phthalocyanine derivative having a phenoxy group, such as PhO-VOPc, is preferred. The phthalocyanine derivative having a phenoxy group is soluble in a solvent. It has the advantage of being easy to handle when forming a light-emitting element. This has the advantage that maintenance of the device used for film formation becomes easier.

[0087] The electron relay layer 707 may further contain a donor material. Alkali metals, alkaline earth metals, rare earth metals and their compounds (alkali metal compounds) (Oxides such as lithium oxide, halides, carbonates such as lithium carbonate and cesium carbonate (including oxides, halides, and carbonates), or rare earth metal compounds Compounds of metals (including oxides, halides, and carbonates), as well as tetrathianaphthacene (abbreviation: TTN), nickelocene, decamethylnickelocene, and other organic compounds are used. By including these donor materials in the electron relay layer 707, This facilitates movement, and the light-emitting element can be driven at a lower voltage.

[0088] When the electron-relay layer 707 contains a donor substance, the above-mentioned In addition to the material, the acceptor level of the acceptor substance contained in the composite material layer 708 A substance with a high LUMO level can be used. Specific energy levels are: , and the LUMO level is in the range of -5.0 eV or more, preferably in the range of -5.0 eV or more and -3.0 eV or less. It is preferable to use a substance having a structure such as a perylene derivative. Nitrogen-containing condensed aromatic compounds are examples of such compounds. Therefore, it is a preferable material to be used for forming the electron relay layer 707. do.

[0089] Specific examples of perylene derivatives include 3,4,9,10-perylenetetracarboxylic dianhydride. (abbreviation: PTCDA), 3,4,9,10-perylenetetracarboxylic bisbenzyl Zoimidazole (abbreviation: PTCBI), N,N'-dioctyl-3,4,9,10-periodic Phenylenetetracarboxylic diimide (abbreviation: PTCDI-CH), N,N'-dihexyl- 3,4,9,10-perylenetetracarboxylic diimide (abbreviation: Hex PTC) It can be obtained.

[0090] Specific examples of nitrogen-containing condensed aromatic compounds include pyrazino[2,3-f][1,10] Phenanthroline-2,3-dicarbonitrile (PPDN), 2,3,6,7,1 0,11-Hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation :HAT(CN)6), 2,3-diphenylpyrido[2,3-b]pyrazine (abbreviation: 2P YPR), 2,3-bis(4-fluorophenyl)pyrido[2,3-b]pyrazine (abbreviation :F2PYPR) etc.

[0091] Other examples include 7,7,8,8-tetracyanoquinodimethane (TCNQ), 1,4 ,5,8,-Naphthalenetetracarboxylic dianhydride (abbreviation: NTCDA), perfluoro Pentacene, copper hexadecafluorophthalocyanine (abbreviation: F 16 CuPc), N,N' Bis 2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluoro NTCDI -CF), 3',4'-dibutyl-5,5''-bis(dicyanomethylene)-5,5' '-Dihydro-2,2':5',2''-terthiophene) (abbreviation: DCMT), methano Fullerenes (e.g., [6,6]-phenyl C 61 Methyl butyrate etc. can be used. can.

[0092] When the electron-relay layer 707 contains a donor substance, the electron-relay layer 707 contains a substance with high electron transporting properties and a donor substance. The electron relay layer 707 may be formed by a method such as co-evaporation with an insulating material.

[0093] The hole injection layer 701, the hole transport layer 702, the light emitting layer 703, and the electron transport layer 704 are made of the above-mentioned materials. Each can be formed using the material.

[0094] Then, the second electrode 108 is formed on the EL layer 106 .

[0095] The second electrode 108 is provided on the opposite side to the light extraction direction and is made of a reflective material. The reflective material is aluminum, gold, platinum, silver, nickel, Metallic materials such as tungsten, chromium, molybdenum, iron, cobalt, copper, or palladium In addition, alloys of aluminum and titanium, aluminum and nickel alloys containing aluminum, such as alloys of aluminum and neodymium (aluminum alloys) Silver-copper alloys, such as silver-gold alloys, can also be used. Furthermore, the metal film or metal oxide film in contact with the aluminum alloy film is preferably By laminating the aluminum alloy film, oxidation of the aluminum alloy film can be suppressed. Examples of materials for the membrane include titanium and titanium oxide. Since it is abundant and inexpensive, the manufacturing cost of the light-emitting element can be reduced, which is preferable. .

[0096] In addition, in the first light emitting element 100 and the second light emitting element 102 arranged in the lighting device, One or both of the first electrode 104 and the second electrode 108 may be a common electrode.

[0097] In addition, in FIG. 2, the first light emitting element 100 and the second light emitting element 102 are organic EL light emitting elements. Although the embodiment of the present invention is not limited to this, the first embodiment may be any other embodiment. An LED or an inorganic EL element can be used as the first or second light emitting element. For example, when an LED is used as the first or second light emitting element, aluminum gallium Indium arsenide (AlGaAs), gallium arsenide phosphide (GaAsP), indium gallium nitride InGaN, gallium nitride (GaN), aluminum gallium nitride (Al GaN), Gallium Phosphide (GaP), Zinc Selenide (ZnSe), Aluminum Indium gallium phosphide (AlGaInP) or the like can be used as the material for the EL layer.

[0098] In addition, the first housing 230 and the second housing 232 are sealed by the space. The arrangement of the light emitting element 100 and the second light emitting element 102 is the same as that of the configurations shown in FIGS. 1(B) and 1(C). 3A and 3B show a first light-emitting element 100 and a second light-emitting element 110. 1 shows different examples of arrangement of the light emitting elements 102.

[0099] FIG. 3(A) is a plan view of the lighting device, and FIG. 3(B) is a view of the lighting device along the line B1-B2 in FIG. 3(A). The lighting device shown in FIGS. 3(A) and 3(B) includes a first light-emitting element 10 The light emitting surface of the second light emitting element 102 is arranged so as to overlap with the light emitting surface of the first light emitting element 102.

[0100] As shown in FIGS. 3A and 3B, the first light-emitting element 100 and the second light-emitting element 10 2 are arranged so that the light emitting surfaces thereof overlap, Light can be emitted from the entire light emitting surface regardless of the voltage applied to the element 102. Therefore, it is possible to prevent flickering of the light emitted by the lighting device, and lighting with improved light emission quality is achieved. It is therefore possible to provide a bright device.

[0101] When the first light emitting element 100 and the second light emitting element 102 are arranged to overlap each other, The optical element 100 and the second light emitting element 102 may be formed by stacking them on the same support, or may be formed separately. The first light emitting element 100 and the second light emitting element 102 formed on the support may be used. .

[0102] In addition, the first light emitting element 100 and the second light emitting element 102 are stacked on the same support. In this case, after forming the first light emitting element 100, an insulating layer is formed on the first light emitting element 100. The second light-emitting element 102 may be formed on the insulating layer. In this way, one of the electrodes included in the first light emitting element 100 and the second light emitting element 102 is connected to a common electrode. It can also be a pole.

[0103] In FIG. 3C, the first electrode 104a and the first EL element provided on the first electrode 104a are shown. The first EL layer 100A and the second electrode 108 disposed on the first EL layer 100A form a first A first light emitting element 100 is configured, and includes a second electrode 108 common to the first light emitting element 100, The second EL layer 102A is provided on the second electrode 108, and the second EL layer 102B is provided on the second EL layer 102A. The second light emitting element 102 is formed by the first electrode 104b and the first electrode 104b. The first light emitting element 100 and the second light emitting element 102 are connected in parallel.

[0104] By using the element structure shown in FIG. 3C, the first and second light-emitting elements per unit area The power efficiency can be improved. By stacking 02, the amount of current supplied to the EL layer of each light-emitting element can be reduced. Therefore, the life of the element can be improved.

[0105] As shown in FIG. 4, the first light-emitting element is held by a holding member 210 having a plurality of encapsulating portions. The light emitting element 100 and the second light emitting element 102 can be held separately. 4(B) is a cross-sectional view taken along line C1-C2 in FIG. 4(A). be.

[0106] The lighting device shown in FIG. 4 has sealing portions 210a and 210b provided in a holding member 210 for the light emitting element. The encapsulation section 210a also contains a first light emitting element provided on the support member 250a. 100 is disposed in the encapsulation portion 210b, and the second light emitting element provided on the support member 250b is disposed in the encapsulation portion 210b. 102 is located.

[0107] The holding member 210, the support member 250a, and the support member 250b are the first housing 230. The same materials as those mentioned above can be used.

[0108] A moisture-absorbing material that acts as a desiccant may be placed inside the enclosing portion 210a and the enclosing portion 210b. Alternatively, an inorganic insulating film may be provided on the inner wall of the encapsulation portion. may be disposed in the encapsulation portion.

[0109] By adopting the configuration shown in FIG. 4, the light emission of the first light-emitting element 100 or the second light-emitting element 102 When a problem occurs with the characteristics (for example, when the light emitting element reaches the end of its life), or when the lighting device When it is desired to change the emitted color to a color that cannot be obtained by the first and second light-emitting elements, The light element 100 or the second light emitting element 102 can be replaced independently. The maintenance or management of the lighting device can be performed at low cost.

[0110] The number and shape of the light emitting elements arranged in the lighting device are not limited to those described above. It is possible to set it appropriately according to the usage of the lighting device. For example, As shown in A), a first light-emitting element 100 and a second light-emitting element 102 each having a rectangular light-emitting region are Alternatively, as shown in FIG. 5B, a plurality of the elements 102 may be arranged in a hexagonal shape. The first light emitting element 100 and the second light emitting element 102 each having a shaped light emitting region are called honeycomb light emitting elements. The light emitting elements may be arranged in a cam structure to improve packing density.

[0111] As described above, the lighting device shown in this embodiment can be applied without using any special means. The color and brightness of the lighting device can be adjusted simply by controlling the voltage applied to the lighting device. Therefore, color and brightness can be adjusted, which improves the convenience of the lighting device. Furthermore, the lighting device according to one embodiment of the present invention can emit light of different colors using the same light source. Therefore, it can be applied to a wide range of applications.

[0112] This embodiment mode can be implemented by being appropriately combined with the configurations described in other embodiments. is.

[0113] (Embodiment 2) In this embodiment mode, an application example of the lighting device shown in Embodiment Mode 1 will be described.

[0114] FIG. 6 shows an example in which a lighting device according to one embodiment of the present invention is used as an indoor lighting device. The lighting device according to one embodiment of the present invention can be used not only as a ceiling lighting device 8202 but also as a wall lighting device. The lighting device can also be used as a desk lamp 8204. Furthermore, the lighting device of one embodiment of the present invention can be used as a surface light Since it has a central light source, the number of components such as light reflectors can be reduced compared to when a point light source is used. They are preferred as indoor lighting devices because they can be used for a long time and generate less heat than incandescent bulbs. It's nice.

[0115] Next, an example in which the lighting device according to one embodiment of the present invention is applied to a lighting device such as an emergency light will be described. Shown in Figure 7.

[0116] FIG. 7A shows an example in which a lighting device according to one embodiment of the present invention is applied to an emergency exit guide light.

[0117] FIG. 7(A) is a diagram showing the appearance of an emergency exit guide light as an example. 8232 can be configured by combining a lighting device and a fluorescent screen with a fluorescent part. In addition, a lighting device that emits a specific color and a shielding device with a transparent portion in the shape shown in the drawing can be used. The lighting device according to one aspect of the present invention may be configured in combination with a light plate. Since it can be lit with a high brightness, it is suitable as an emergency exit guide light that needs to be kept on at all times.

[0118] FIG. 7B shows an example in which a lighting device according to one embodiment of the present invention is applied to outdoor lighting.

[0119] An example of outdoor lighting is a street lamp. The light source device can have a housing 8242 and a lighting unit 8244. A plurality of lighting devices according to this embodiment can be arranged in the lighting unit 8244. As shown in FIG. 1, streetlights are installed along roads, for example, and illuminate the surroundings with lighting units 8244. This allows for improved visibility of the surrounding area, including the road.

[0120] In addition, when supplying power voltage to a street light, for example, as shown in FIG. 7(B), The power supply voltage can be supplied via the power line 8248 of 6. However, it is not limited to this. For example, a photoelectric conversion device is provided in a housing 8242, and a voltage obtained by the photoelectric conversion device is supplied to a power supply It can also be used as pressure.

[0121] 7C and 7D show examples in which the lighting device of one embodiment of the present invention is applied to a portable light. FIG. 7(C) shows the structure of the wearable light, and FIG. 7(D) shows the structure of the wearable light. FIG. 1 is a diagram showing the configuration of a portable light.

[0122] The wearable light shown in FIG. 7(C) has a wearing part 8252 and a lighting part 8254. 254 is fixed to the mounting portion 8252. The lighting device according to one aspect of the present invention includes the lighting unit 8 The wearable light shown in FIG. 7(C) can be used for the head. The lighting unit 8254 can be attached to the surface of the lamp and emit light. By using the light source of the source, the visibility of the surroundings can be improved. The 254 is lightweight, which reduces the burden on the head when worn.

[0123] The configuration of the wearable light is not limited to that shown in FIG. 7(C). For example, the wearable light may be The belt is made of a flat string or rubber string, and the lighting unit 8254 is fixed to the belt. It can also be configured to be wrapped directly around the head.

[0124] The handheld light shown in FIG. 7(D) includes a housing 8262, a lighting unit 8266, and a switch 8267. 64. A lighting device which is one embodiment of the present invention can be used for the lighting portion 8266. By using the lighting device of one embodiment of the present invention for the lighting portion 8266, 66 can be made thinner and smaller, making it easier to carry. can be done.

[0125] The switch 8264 has a function of controlling whether the lighting unit 8266 emits light or not. The switch 8264 may have a function of adjusting the brightness of the lighting unit 8266 when it is emitting light, for example. It can also be done as follows.

[0126] The handheld light shown in FIG. 7(D) emits light from a lighting unit 8266 by a switch 8264. This allows the surrounding area to be illuminated, improving visibility. Furthermore, since the lighting device according to one embodiment of the present invention includes a surface light source, it is possible to reduce the size of the light source. It is also possible to reduce the number of components such as light reflectors compared to when a light source is used.

[0127] In this embodiment, the contents described in each drawing may be the same as those described in another embodiment. However, they can be freely combined or replaced as appropriate. [Example]

[0128] In this embodiment, a specific configuration example of a light emitting element applicable to a lighting device and a lighting device using the same will be described. The device will be explained using the drawings.

[0129] A method for manufacturing the first light-emitting element 200 of this example will be described with reference to FIG. A method for manufacturing the second light-emitting element 202 of this embodiment will be described with reference to FIG. The structural formula of the organic compound used is shown below.

[0130] [ka]

[0131] (First light-emitting element 200) First, indium tin oxide containing silicon oxide is formed on the substrate 1100 by sputtering. The first electrode 1101 was formed by depositing a thin film of 110 nm. In this example, the first electrode 1101 was used as an anode.

[0132] Next, the surface on which the first electrode 1101 is formed is placed downward. The substrate 1100 thus formed is fixed to a substrate holder provided in a vacuum deposition apparatus, and 10 -4 P After the pressure was reduced to about 1000 kJ / cm, 9-[4-(9-phenylcarbazol-1-yl)-2-( ... [phenyl-3-yl]phenyl-10-phenylanthracene (abbreviation: PCzPA) and oxidized moiety The hole injection layer 1111 was formed by co-evaporation of bismuth (VI). The weight ratio of PCzPA to molybdenum (VI) oxide was 4:2 (=PCz The co-evaporation method was adjusted so that the concentration of PA and molybdenum oxide was 100%. This is a deposition method in which deposition is carried out simultaneously from multiple evaporation sources.

[0133] Next, a film of PCzPA was formed on the hole injection layer 1111 to a thickness of 30 nm. A transport layer 1112 was formed.

[0134] Furthermore, 9-[4-(N-carbazolyl)phenyl]-10-phenylanthracene (abbreviation CzPA) and N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl )phenyl)-N,N'-diphenylpyrene-1,6-diamine (abbreviation: 1,6FLPA Prn) was co-evaporated to form a light-emitting layer 1113 on the hole transport layer 1112. The weight ratio of zPA and 1,6FLPAPrn was 1:0.05 (= CzPA:1,6FLP The thickness of the light-emitting layer 1113 was adjusted to 20 nm.

[0135] Next, a CzPA film was formed on the light-emitting layer 1113 to a thickness of 15 nm. A transfer layer 1114a was formed.

[0136] Then, bathophenanthroline (abbreviation: BPhen) was applied to the first electron transport layer 1114a. A film was formed to a thickness of 15 nm to form the second electron transport layer 1114b.

[0137] Furthermore, lithium fluoride (LiF) was deposited on the second electron transport layer 1114b to a thickness of 1 nm. An electron injection layer 1115 was formed by evaporation.

[0138] Finally, a 200 nm film of aluminum was deposited as the second electrode 1103, which served as the cathode. The first light emitting element 200 was fabricated by vapor deposition to a thickness of 1000 mm.

[0139] (Second light-emitting element 202) The first electrode 1101 was fabricated in the same manner as in the first light-emitting element 200 .

[0140] Next, the surface on which the first electrode 1101 is formed is placed downward. The substrate 1100 thus formed is fixed to a substrate holder provided in a vacuum deposition apparatus, and 10 -4 P After the pressure was reduced to about a, PCzPA and molybdenum (VI) oxide were applied to the first electrode 1101. The hole injection layer 1111 was formed by co-evaporating the following: The weight ratio of zPA to molybdenum (VI) oxide was 4:2 (= PCzPA: molybdenum (VI) oxide). The temperature was adjusted to be 100°C.

[0141] Next, 4-phenyl-4'-(9-phenylfluorene-9- A film of 20 nm thick was formed using BPAFLP. Then, a hole transport layer 1112 was formed.

[0142] Then, 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]ky Noxalin (abbreviation: 2mDBTPDBq-II) and 4-phenyl-4'-(9-phenyl (9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), (Acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium (III) (abbreviation: Ir(mppr-Me)2(acac)) was co-evaporated to form a hole transport layer. A first light-emitting layer 1113a was formed on the first light-emitting layer 1112. The weight ratio of PCBA1BP to Ir(mppr-Me)2(acac) was 0.6:0.2. :0.06(=2mDBTPDBq-II:PCBA1BP:Ir(mppr-Me)2 The thickness of the first light-emitting layer 1113a was adjusted to be 15 nm. It was decided.

[0143] Furthermore, 2mDBTPDBq-II and Ir(mppr-Me)2(acac) were co-evaporated. Then, the second light-emitting layer 1113b was formed on the first light-emitting layer 1113a. The weight ratio of PDBq-II to Ir(mppr-Me)2(acac) was 1:0.06 (= 2mDBTPDBq-II:Ir(mppr-Me)2acac) The thickness of the second light emitting layer 1113b was set to 15 nm.

[0144] Next, 2mDBTPDBq-II was deposited on the second light-emitting layer 1113b to a thickness of 25 nm. The first electron transport layer 1114a was formed as follows.

[0145] Thereafter, similarly to the first light-emitting device 200, the second electron transport layer 1114b and the electron injection layer 11 15, a second electrode 1103 was formed, and a second light-emitting element 202 was fabricated.

[0146] In the above-described deposition process, the deposition was all carried out by resistance heating.

[0147] The first light-emitting element 200 and the second light-emitting element 202 were placed in a glove box with a nitrogen atmosphere. After sealing the light emitting elements to prevent them from being exposed to the atmosphere, The operating characteristics of the device were measured. The measurements were carried out at room temperature (an atmosphere maintained at 25°C). It was.

[0148] FIG. 9A shows the voltage-luminance characteristics of the first light-emitting element 200 and the second light-emitting element 202. In Figure 9(A), the horizontal axis represents voltage (V) and the vertical axis represents brightness (cd / m 2 ) and the first The voltage-luminous flux characteristics of the optical element 200 and the second light emitting element 202 are shown in FIG. 9(B) and FIG. 9(C). Figure 9(C) is an enlarged view of the range of 2.8V to 3.4V in Figure 9(B). In Figures 9(B) and 9(C), the horizontal axis represents voltage (V) and the vertical axis represents luminous flux (lm).

[0149] From FIG. 9A, the light emission start voltage of the second light emitting element 202 is 2.3 V, and the first light emitting This is lower than the light emission start voltage of the element 200, 2.7 V. When the light emitting element 202 is connected in parallel, the applied voltage is 2.3 V or more and less than 2.7 V. In this case, only light emitted from the second light emitting element 202 is obtained.

[0150] Furthermore, as shown in Figures 9(B) and 9(C), as the applied voltage increases, Since light emission from the first light emitting element 200 is obtained, the first light emission The rate at which the device 200 emits light increases.

[0151] The illumination device of this embodiment has a first light emitting element 200 and a second light emitting element 202 connected in parallel. The characteristics were obtained by calculation. The calculated color change due to the difference in applied voltage was calculated as CIE chromaticity coordinates. The graph shows the relationship between the applied voltage and the luminous color and intensity (brightness and luminous flux). The results are shown in Table 1. The luminous flux-color temperature characteristics of the lighting device of this example are shown in FIG. In the graph, the horizontal axis represents the total luminous flux (lm) of the first light-emitting element 200 and the second light-emitting element 202. The vertical axis indicates color temperature (K).

[0152] [Table 1]

[0153] In this embodiment, the first light-emitting element 200 emits blue light derived from 1,6FLPAPrn. On the other hand, the second light-emitting element 202 emits orange light derived from Ir(mppr-Me)2(acac). A first light emitting element 200 and a second light emitting element 202 having the same area are connected in parallel. When the applied voltage is 2.8 V, the second light emitting element 202 As the applied voltage increases, the light emitted from the lighting device becomes orange. The flux becomes larger, and the proportion of light emitted from the first light-emitting element 200 to the total luminous flux becomes larger. Therefore, the light color of the lighting device changes in sequence from warm white to white to daylight white.

[0154] Furthermore, when the applied voltage is 3.2 V or more, the luminous flux of the first light emitting element 200 increases sufficiently. Therefore, the luminous flux can be increased while maintaining the light emission color of the lighting device at daylight white.

[0155] As described above, the lighting device shown in this embodiment is a device for lighting light emitting elements having different emission colors and emission start voltages. By connecting the elements in parallel, it is possible to change the applied voltage without using any special means. Color and light can be adjusted.

[0156] In addition, when the total luminous flux of the lighting device shown in this embodiment is small, it is possible to emit warm colors (orange or warm white). As the total luminous flux increases (applied voltage increases), the color approaches white. Generally, warm lighting should be used in darker settings, and white lighting should be used in brighter settings. Therefore, the lighting device of this embodiment has a color tone and brightness It is also effective in terms of relationships between people. [Explanation of symbols]

[0157] 100 First light-emitting element 100A First EL layer 102 second light-emitting element 102A Second EL layer 104 First electrode 104a first electrode 104b first electrode 106 EL layer 108 Second electrode 200 First light-emitting element 202 Second light-emitting element 210 Retaining member 210a Enclosure 210b Enclosure 230 cabinet 232 Case 250a support member 250b support member 701 Hole injection layer 702 Hole transport layer 703 Light-emitting layer 704 Electron transport layer 705 Electron injection layer 706 Electron injection buffer layer 707 Electronic Relay Layer 708 Composite material layer 1100 board 1101 First electrode 1103 Second electrode 1111 Hole injection layer 1112 Hole transport layer 1113 Light-emitting layer 1113a First light-emitting layer 1113b Second light-emitting layer 1114a First electron transport layer 1114b Second electron transport layer 1115 Electron injection layer 8202 Ceiling lighting equipment 8204 Wall lighting device 8206 Tabletop lighting equipment 8232 Evacuation exit guide light 8242 Case 8244 Lighting Department 8246 Electric pole 8248 Power Lines 8252 Mounting part 8254 Lighting Department 8262 Case 8264 Switch 8266 Lighting Department

Claims

1. a first light-emitting element and a second light-emitting element connected in parallel to the first light-emitting element; a lighting device in which an emission color obtained by combining a first emission color of the first light-emitting element and a second emission color of the second light-emitting element is controlled by a voltage applied to the first light-emitting element and the second light-emitting element, the first light-emitting element has a first electrode, a first hole injection layer on the first electrode, a first hole transport layer on the first hole injection layer, a first light-emitting layer on the first hole transport layer, and a second electrode on the first light-emitting layer; the second light-emitting element has a third electrode, a second hole injection layer on the third electrode, a second hole transport layer on the second hole injection layer, a second light-emitting layer on the second hole transport layer, and a fourth electrode on the second light-emitting layer; the second emission color has a longer wavelength than the first emission color; the second light-emitting element has a characteristic of starting to emit light at a voltage lower than that of the first light-emitting element, the first hole injection layer includes a first organic compound having a high hole transport property and a first acceptor substance; the second hole injection layer includes a second organic compound having a high hole transport property and a second acceptor substance; the second light-emitting layer has an organometallic complex having a pyrazine derivative as a ligand, the first light-emitting element and the second light-emitting element have approximately the same area; The lighting device has a function of being able to adjust the color temperature to 2200K or more and 5100K or less, and the second light-emitting element emits light with a higher brightness than the first light-emitting element over the temperature range of the color temperature.

2. a first light-emitting element and a second light-emitting element connected in parallel to the first light-emitting element; a lighting device in which an emission color obtained by combining a first emission color of the first light-emitting element and a second emission color of the second light-emitting element is controlled by a voltage applied to the first light-emitting element and the second light-emitting element, the first light-emitting element has a first electrode, a first hole injection layer on the first electrode, a first hole transport layer on the first hole injection layer, a first light-emitting layer on the first hole transport layer, and a second electrode on the first light-emitting layer; the second light-emitting element has a third electrode, a second hole injection layer on the third electrode, a second hole transport layer on the second hole injection layer, a second light-emitting layer on the second hole transport layer, and a fourth electrode on the second light-emitting layer; the second emission color has a longer wavelength than the first emission color; the second light-emitting element has a characteristic of starting to emit light at a voltage lower than that of the first light-emitting element, the first hole injection layer includes a first organic compound having a high hole transport property and a first acceptor substance; the second hole injection layer includes a second organic compound having a high hole transport property and a second acceptor substance; the first acceptor substance and the second acceptor substance are the same material; the first hole transport layer and the second hole transport layer have different materials; the second light-emitting layer has an organometallic complex having a pyrazine derivative as a ligand, the first light-emitting element and the second light-emitting element have approximately the same area; The lighting device has a function of being able to adjust the color temperature to 2200K or more and 5100K or less, and the second light-emitting element emits light with a higher brightness than the first light-emitting element over the temperature range of the color temperature.

3. a first light-emitting element and a second light-emitting element connected in parallel to the first light-emitting element; a lighting device in which an emission color obtained by combining a first emission color of the first light-emitting element and a second emission color of the second light-emitting element is controlled by a voltage applied to the first light-emitting element and the second light-emitting element, the first light-emitting element has a first electrode, a first hole injection layer on the first electrode, a first hole transport layer on the first hole injection layer, a first light-emitting layer on the first hole transport layer, and a second electrode on the first light-emitting layer; the second light-emitting element has a third electrode, a second hole injection layer on the third electrode, a second hole transport layer on the second hole injection layer, a second light-emitting layer on the second hole transport layer, and a fourth electrode on the second light-emitting layer; the first light-emitting element emits light having an emission spectrum peak in the range of 450 nm to 510 nm, the second light-emitting element emits light having an emission spectrum peak in the range of 550 nm to 600 nm, the second light-emitting element has a characteristic of starting to emit light at a voltage lower than that of the first light-emitting element, the first hole injection layer includes a first organic compound having a high hole transport property and a first acceptor substance; the second hole injection layer includes a second organic compound having a high hole transport property and a second acceptor substance; the first acceptor substance and the second acceptor substance are the same material; the first hole transport layer and the second hole transport layer have different materials; the second light-emitting layer has an organometallic complex having a pyrazine derivative as a ligand, the first light-emitting element and the second light-emitting element have approximately the same area; The lighting device has a function of being able to adjust the color temperature to 2200K or more and 5100K or less, and the second light-emitting element emits light with a higher brightness than the first light-emitting element over the temperature range of the color temperature.

4. In any one of claims 1 to 3, When a voltage is applied to the first light-emitting element to start emitting light, the luminous emittance of the second light-emitting element is 300 lm / m ２ More than 30000lm / m ２ Less than 1000W, lighting equipment.

5. In any one of claims 1 to 4, when the applied voltage is a first voltage, the combined luminous color of the first luminous color and the second luminous color is neutral white; As a voltage higher than the first voltage is applied, the luminous flux of the combined luminous color of the first luminous color and the second luminous color is increased while maintaining a neutral white color, As a voltage lower than the first voltage is applied, the emission color obtained by combining the first emission color and the second emission color changes to a warmer color and the luminous flux decreases.

Images