Light-emitting devices, light-emitting apparatus, electronic equipment and lighting apparatus

Abstract

To provide a light-emitting device in which energy transfer from a host material to a guest material is efficiently carried out in a light-emitting layer of the light-emitting device, and which is also highly reliable.SOLUTION: In a light-emitting layer of a light-emitting device, the T1 level and S1 level of a host material and a guest material satisfy specific ranges, ensuring efficient energy transfer from the host material to the guest material while also improving device reliability.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] One aspect of the present invention relates to a light-emitting device, a light-emitting apparatus, an electronic device, and a lighting apparatus. However, However, one aspect of the present invention is not limited to those. That is, one aspect of the present invention is a product, a method, The present invention relates to a manufacturing method or a driving method. Alternatively, one aspect of the present invention relates to a process, machine, or This relates to a manufacture or composition of matter. [Background technology]

[0002] Light-emitting devices (also called organic EL devices) that consist of an EL layer sandwiched between a pair of electrodes are thin. Because they possess characteristics such as being lightweight, having a fast response to input signals, and having low power consumption, these Displays incorporating this technology are attracting attention as next-generation flat-panel displays. .

[0003] The light-emitting device uses a voltage applied between a pair of electrodes to emit electrons injected from each electrode. And the holes recombine in the EL layer, and the light-emitting material (organic compound) contained in the EL layer becomes excited It enters an excited state, and emits light when that excited state returns to the ground state. Note that the types of excited states are as follows: So, the singlet excited state (S * ) and triplet excited state (T * ) and from the singlet excited state The emission from this state is called fluorescence, and the emission from the triplet excited state is called phosphorescence. The statistical generation ratios for these in S * :T * It is believed that the ratio is 1:3. The emission spectrum obtained from a substance is unique to that substance, and differs in type of organic emission By using the compound as a light-emitting material, it is possible to obtain light-emitting devices with various emission colors. Cut.

[0004] Regarding such light-emitting devices, in order to improve their device characteristics and reliability, Active efforts are being made to improve the structure and develop new materials (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2010-182699 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] In order to improve the device characteristics and reliability of light-emitting devices, Considering the energy transfer mechanism between the host material and the guest material, the device Reducing damage associated with the drive system is important.

[0007] Therefore, in one aspect of the present invention, in the light-emitting layer of a light-emitting device, the host material is replaced with a guest material. This not only ensures efficient energy transfer to the material, but also provides highly reliable light-emitting devices. ru.

[0008] Furthermore, the description of these problems does not preclude the existence of other problems. The approach does not need to solve all of these problems. This will become clear from the description in the specification, drawings, claims, etc., and the specification, drawings It is possible to extract other issues from the descriptions in the surfaces, claims, etc. [Means for solving the problem]

[0009] One aspect of the present invention is that in the light-emitting layer of a light-emitting device, the T1 level and the S1 level of the host material and the guest material satisfy a certain range, so that energy transfer from the host material to the guest material can be efficiently performed and the reliability of the light-emitting device can be improved.

[0010] One aspect of the present invention is a light-emitting device having an EL layer between a pair of electrodes. The EL layer has a light-emitting layer, and the light-emitting layer has a first organic compound, a second organic compound, and a light-emitting substance. Among the T1 level of the first organic compound and the T1 level of the second organic compound, the lower T1 level (T H(edge) ), and the T1 level of the light-emitting substance (T D(edge) ) satisfy the following formula (1 ), and the difference between the S1 level (S ’ H(edge) ) of the material obtained by mixing the first organic compound and the second organic compound and T H(edge) satisfies the following formula (2).

[0011] [Number]

[0012] (However, T H(edge) refers to the lower T1 level among the T1 levels derived from the emission end on the short wavelength side of the phosphorescence spectrum of the first organic compound and the second organic compound. Also, T D(edge)

[0013] H(edge) refers to the T1 level derived from the absorption end of the absorption spectrum of the light-emitting substance. Also, S’ refers to the S1 level derived from the emission end on the short wavelength side of the fluorescence spectrum of the material obtained by mixing the first organic compound and the second organic compound. [[ID={57]] )

[0013] ​​

number

[0014] Another aspect of the present invention includes an EL layer between a pair of electrodes, the EL layer having a light-emitting layer, The light-emitting layer comprises a first organic compound, a second organic compound, and a light-emitting substance, and the first organic compound Of the T1 levels of the compound and the T1 level of the second organic compound, the one with the lower energy level. 1 level (T H(edge) ), and the T1 level (T D(edge) ) is as follows A material that satisfies formula (3) and is a mixture of the first organic compound and the second organic compound is classified as S1. Place(S' H(edge) ) and, T H(edge) The difference is the amount of light emitted that satisfies the following equation (4) It's a vice.

[0015]

number

[0016] (However, T H(edge) The phosphorescence spectrum of the first organic compound and the second organic compound Of the T1 levels derived from the emission edge on the short wavelength side of Toll, the T1 with the lower energy It refers to a level. Also, T D(edge) It is derived from the absorption edge of the absorption spectrum of the luminescent material. This refers to the T1 level. Also, S' H(edge) are the first organic compound and the second organic compound This refers to the S1 level derived from the emission edge at the short wavelength side of the fluorescence spectrum of a material mixed with [the other material]. vinegar).

[0017]

number

[0018] Furthermore, in each of the above configurations, the first organic compound and the second organic compound form an excited complex. This is a combination that results in the S1 level (S' H(edge) ) is the fluorescence spectrum of the excited complex. It is derived from the emission end on the short wavelength side.

[0019] Furthermore, in each of the above configurations, the first organic compound is a π-electron-deficient heteroaromatic compound. This is preferable. Furthermore, the first organic compound may be a pyridine ring, a diazine ring, or a tria ring. It is preferable that the first organic compound is phlodiaz. It has a structure in which an aromatic ring is condensed onto a furan ring in the furan skeleton.

[0020] Furthermore, in each of the above configurations, a light-emitting device in which the light-emitting material is a phosphorescent material is one embodiment of the present invention. It is included in such a manner. In addition, the second organic compound is a carbazole derivative. The present invention also includes light-emitting devices in which the carbazole derivative is preferably a bicarbazole derivative. This is included in one embodiment. Particularly preferred as the second organic compound is 3,3'-bicarbazole. These are derivatives. These carbazole derivatives have an aromatic amine skeleton (specifically, It is preferable that it does not have a lyarylamine skeleton.

[0021] Furthermore, one aspect of the present invention is a light-emitting device having the above-described light-emitting device (also called a light-emitting element). In addition, electronic devices that utilize light-emitting devices or light-emitting equipment (specifically, light-emitting devices and Electronic equipment having a light-emitting device and connection terminals or operating keys) and lighting devices (specifically) This category also includes lighting devices (which include a light-emitting device or apparatus and a housing). Therefore, in this specification, a light-emitting device refers to an image display device or a light source (illumination device). This refers to (including) connectors in light-emitting devices, such as FPC (Flexible Printed Circuit). (Tuned Circuit) or TCP (Tape Carrier Packaging) e) A module to which the TCP is attached, a module with a printed circuit board located beyond the TCP. , or an IC (integrated circuit) is created using the COG (Chip On Glass) method in the light-emitting device. Modules in which the circuit is directly implemented are also included in the definition of a light-emitting device. [Effects of the Invention]

[0022] According to one aspect of the present invention, energy transfer from the host material to the guest material in the light-emitting layer is efficient. This provides a novel light-emitting device that not only performs the task efficiently but also offers improved reliability. It is possible.

[0023] Furthermore, the description of these effects does not preclude the existence of other effects. The embodiment does not necessarily have to have all of these effects. Furthermore, other effects are... This will become clear from the description in the specification, drawings, claims, etc., and the specification, drawings Furthermore, it is possible to extract effects other than those mentioned above from the claims and other descriptions. This allows us to provide a novel light-emitting device that can improve the reliability of the system. [Brief explanation of the drawing]

[0024] [Figure 1] Figure 1 shows the relationship between TH(edge) and TD(edge) in terms of normalized lifetime. [Figure 2] Figure 2 shows the relationship between TH(edge) and TD(edge) and the normalized external quantum efficiency. [Figure 3] Figure 3 shows the method for calculating TH(edge) from the phosphorescence spectrum. [Figure 4]Figure 4 shows the method for calculating TH(edge) from the phosphorescence spectrum. [Figure 5] Figure 5 shows the method for calculating TH(edge) from the phosphorescence spectrum. [Figure 6] Figure 6 shows the method for calculating TD(edge) from the phosphorescence spectrum. [Figure 7] Figure 7 shows the method for calculating S'H(edge)-TH(edge) from the absorption spectrum. [Figure 8] Figure 8(A) is a diagram illustrating the structure of a light-emitting device. Figure 8(B) is a diagram illustrating the structure of a light-emitting device. [Figure 9] Figure 9(A) is a diagram illustrating the light-emitting device. Figure 9(B) is a diagram illustrating the light-emitting device. Figure 9(C) is a diagram illustrating the light-emitting device. [Figure 10] Figure 10(A) is a diagram illustrating the top view of the light-emitting device. Figure 10(B) is a diagram illustrating the cross-section of the light-emitting device. [Figure 11] Figure 11(A) is a diagram illustrating a mobile computer. Figure 11(B) is a diagram illustrating a portable image playback device. Figure 11(C) is a diagram illustrating a digital camera. Figure 11(D) is a diagram illustrating a personal information terminal (PAD). Figure 11(E) is a diagram illustrating a PAD. Figure 11(F) is a diagram illustrating a television system. Figure 11(G) is a diagram illustrating a PAD. [Figure 12] Figures 12(A), 12(B), and 12(C) illustrate electronic devices. [Figure 13] Figures 13(A) and 13(B) illustrate an automobile. [Figure 14] Figures 14(A) and 14(B) illustrate the lighting device. [Figure 15] Figure 15 is a diagram illustrating a light-emitting device. [Figure 16]Figure 16 shows the luminance-current density characteristics of light-emitting device 1 and comparative light-emitting device a1. [Figure 17] Figure 17 shows the luminance-voltage characteristics of light-emitting device 1 and comparison light-emitting device a1. [Figure 18] Figure 18 shows the current efficiency-luminance characteristics of light-emitting device 1 and comparative light-emitting device a1. [Figure 19] Figure 19 shows the current-voltage characteristics of light-emitting device 1 and comparative light-emitting device a1. [Figure 20] Figure 20 shows the emission spectra of light-emitting device 1 and comparative light-emitting device a1. [Figure 21] Figure 21 shows the reliability of light-emitting device 1 and comparison light-emitting device a1. [Figure 22] Figure 22 shows the luminance-current density characteristics of light-emitting device 2 and comparative light-emitting device a2. [Figure 23] Figure 23 shows the luminance-voltage characteristics of light-emitting device 2 and comparison light-emitting device a2. [Figure 24] Figure 24 shows the current efficiency-luminance characteristics of light-emitting device 2 and comparative light-emitting device a2. [Figure 25] Figure 25 shows the current-voltage characteristics of light-emitting device 2 and comparison light-emitting device a2. [Figure 26] Figure 26 shows the emission spectra of light-emitting device 2 and comparative light-emitting device a2. [Figure 27] Figure 27 shows the reliability of light-emitting device 2 and comparison light-emitting device a2. [Figure 28] Figure 28 shows the luminance-current density characteristics of light-emitting device 3, light-emitting device 4, and comparative light-emitting device a3. [Figure 29] Figure 29 shows the luminance-voltage characteristics of light-emitting device 3, light-emitting device 4, and comparison light-emitting device a3. [Figure 30]Figure 30 shows the current efficiency-luminance characteristics of light-emitting device 3, light-emitting device 4, and comparative light-emitting device a3. [Figure 31] Figure 31 shows the current-voltage characteristics of light-emitting device 3, light-emitting device 4, and comparison light-emitting device a3. [Figure 32] Figure 32 shows the emission spectra of light-emitting device 3, light-emitting device 4, and comparative light-emitting device a3. [Figure 33] Figure 33 shows the reliability of light-emitting device 3, light-emitting device 4, and comparison light-emitting device a3. [Figure 34] Figure 34 shows the luminance-current density characteristics of light-emitting device 5 and comparative light-emitting device a4. [Figure 35] Figure 35 shows the luminance-voltage characteristics of light-emitting device 5 and comparative light-emitting device a4. [Figure 36] Figure 36 shows the current efficiency-luminance characteristics of light-emitting device 5 and comparative light-emitting device a4. [Figure 37] Figure 37 shows the current-voltage characteristics of light-emitting device 5 and comparative light-emitting device a4. [Figure 38] Figure 38 shows the emission spectra of light-emitting device 5 and comparative light-emitting device a4. [Figure 39] Figure 39 shows the reliability of light-emitting device 5 and comparative light-emitting device a4. [Figure 40] Figure 40 shows the luminance-current density characteristics of light-emitting device 6, light-emitting device 7, and comparative light-emitting device a5. [Figure 41] Figure 41 shows the luminance-voltage characteristics of light-emitting device 6, light-emitting device 7, and comparative light-emitting device a5. [Figure 42] Figure 42 shows the current efficiency-luminance characteristics of light-emitting device 6, light-emitting device 7, and comparative light-emitting device a5. [Figure 43] Figure 43 shows the current-voltage characteristics of light-emitting device 6, light-emitting device 7, and comparison light-emitting device a5. [Figure 44] Figure 44 shows the emission spectra of light-emitting device 6, light-emitting device 7, and comparative light-emitting device a5. [Figure 45] Figure 45 shows the reliability of light-emitting device 6, light-emitting device 7, and comparison light-emitting device a5. [Figure 46] Figure 46 shows the luminance-current density characteristics of light-emitting device 8, reference light-emitting device b1, and reference light-emitting device b2. [Figure 47] Figure 47 shows the luminance-voltage characteristics of light-emitting device 8, reference light-emitting device b1, and reference light-emitting device b2. [Figure 48] Figure 48 shows the current efficiency-luminance characteristics of light-emitting device 8, reference light-emitting device b1, and reference light-emitting device b2. [Figure 49] Figure 49 shows the current-voltage characteristics of light-emitting device 8, reference light-emitting device b1, and reference light-emitting device b2. [Figure 50] Figure 50 shows the emission spectra of light-emitting device 8, reference light-emitting device b1, and reference light-emitting device b2. [Figure 51] Figure 51 shows the reliability of light-emitting device 8, reference light-emitting device b1, and reference light-emitting device b2. [Figure 52] Figure 52 shows the luminance-current density characteristics of light-emitting device 9, reference light-emitting device c1, and reference light-emitting device c2. [Figure 53] Figure 53 shows the luminance-voltage characteristics of light-emitting device 9, reference light-emitting device c1, and reference light-emitting device c2. [Figure 54] Figure 54 shows the current efficiency-luminance characteristics of light-emitting device 9, reference light-emitting device c1, and reference light-emitting device c2. [Figure 55] Figure 55 shows the current-voltage characteristics of light-emitting device 9, reference light-emitting device c1, and reference light-emitting device c2. [Figure 56]Figure 56 shows the emission spectra of light-emitting device 9, reference light-emitting device c1, and reference light-emitting device c2. [Figure 57] Figure 57 shows the reliability of light-emitting device 9, reference light-emitting device c1, and reference light-emitting device c2. [Figure 58] Figure 58 shows the luminance-current density characteristics of light-emitting devices 10 and 11. [Figure 59] Figure 59 shows the luminance-voltage characteristics of light-emitting devices 10 and 11. [Figure 60] Figure 60 shows the current efficiency-luminance characteristics of light-emitting devices 10 and 11. [Figure 61] Figure 61 shows the current-voltage characteristics of light-emitting devices 10 and 11. [Figure 62] Figure 62 shows the emission spectra of light-emitting devices 10 and 11. [Figure 63] Figure 63 shows the reliability of light-emitting devices 10 and 11. [Figure 64] Figure 64 is the 1H-NMR chart of the organic compound [Ir(dmdppr-mCP)2(dpm)]. [Figure 65] Figure 65 is the 1H-NMR chart of the organic compound [Ir(dmdppr-m3CP)2(dpm)]. [Modes for carrying out the invention]

[0025] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is as follows Not limited to the description, the form and details thereof may be described without departing from the spirit and scope of the present invention. It is possible to modify it in various ways. Therefore, the present invention is described in the following embodiments. It is not meant to be interpreted in this way only.

[0026] Note that the position, size, and scope of each component shown in the drawings, etc., are for ease of understanding. The position, size, and range of the edges may not be shown. Therefore, the disclosed invention is not necessarily However, this is not limited to the location, size, and scope disclosed in drawings, etc.

[0027] Furthermore, in this specification and other documents, when describing the structure of the invention using drawings, the same thing may be referred to as The symbols used are consistent across different drawings.

[0028] (Embodiment 1) In this embodiment, a light-emitting device according to one aspect of the present invention will be described. The vice has a structure in which an EL layer is sandwiched between a pair of electrodes, and the EL layer is at least an emissive layer It also has hole injection layers, hole transport layers, electron transport layers, and electron injection layers. Functional layers such as these can also be added.

[0029] The light-emitting layer is a layer containing a light-emitting substance (guest material), and the rest of the layer contains a host material. In one aspect of the present invention, the light-emitting layer of the light-emitting device comprises a plurality of host materials. Organic compounds (for example, the first organic compound, and the second organic compound (or host material) It has, and assist materials, etc.

[0030] Light emission in light-emitting devices occurs in the light-emitting layer through the recombination of carriers (holes and electrons). Energy transfer occurs from the excited host material to the guest material, and the guest material This is obtained by the emission of light. Note that the light-emitting device described in this embodiment is a plurality A material having a host material (a first organic compound and a second organic compound), and a mixture thereof. From the excited state (including cases where multiple host materials form an excited complex and cases where they do not) The configuration has such that phosphorescence is obtained as a result of energy transfer to the guest (phosphorescent material). Furthermore, energy transfer from the triplet excited state of the mixed material to the guest material is performed by reverse intersystem interaction. If the difference is unlikely to occur (not dominant), the lower T1 level of the mixed material will be used. Energy is transferred from there.

[0031] Furthermore, in the host material in which the first organic compound and the second organic compound are mixed as described above, Therefore, if inverse interterm crossing is unlikely to occur (i.e., not dominant), then at least the following two conditions apply. It is thought that one of the following conditions must be met.

[0032] The first condition is that at least one of the first organic compound and the second organic compound is reversed. The advantage is that intersystem cross-relationships are less likely to occur. Specifically, the first organic compound and the second organic compound In all cases, Δ is the difference between the singlet excitation level (S1 level) and the triplet excitation level (T1 level). The Est is 0.2 eV or higher. In this case, the first organic compound and the second organic compound If the compound does not form an excited complex, the material is a mixture of the first organic compound and the second organic compound. S1 level of the material (S' H(edge) ) (Derived from the fluorescence spectrum of the mixed material) and, The T1 energy level of the first organic compound and the T1 energy level of the second organic compound The lower T1 level (T H(edge) The difference from ) will also always be 0.2 eV or more. Furthermore, even in a host material in which the first organic compound and the second organic compound are mixed, the reverse intersystem Crossover is unlikely to occur.

[0033] The second condition is when the first organic compound and the second organic compound form an excited complex. This must be taken into consideration. When an excited complex is formed, the first organic compound and the second organic compound A new S1 level is formed that is lower than the S1 level of the compound. In other words, the S1 level of the excited complex is S1 level (S' H(edge) (Derived from the fluorescence spectrum of the excited complex) This results in ( ). At this time, if the T1 levels of the first organic compound and the second organic compound are sufficiently high, Reverse intersystem crossing occurs in the initial complex. Therefore, the excited complex does not undergo reverse intersystem crossing. The conditions under which this becomes difficult include the S1 level of the excited complex (i.e., S' H(edge) ) and T H(edge ) The difference is 0.2 eV or more.

[0034] Based on the above, in a host material in which the first organic compound and the second organic compound are mixed, The conditions under which reverse intersystem crossing is unlikely to occur are when the host material forms an excited complex and when it does not. In either case, the S1 standard of the material obtained by mixing the first organic compound and the second organic compound. Place(S' H(edge) (Derived from the fluorescence spectrum of the mixed material) and the first organic compound The lower of the T1 levels of the compound and the T1 levels of the second organic compound. T1 level (T H(edge) This is the case when the difference between ) and is 0.2 eV or more. The transfer of triplet excitation energy occurs when the first organic compound and the second organic compound are mixed. Among the stock materials, the movement from those with lower T1 levels to the guest material is dominant. That is, Among the host materials in which the first organic compound and the second organic compound are mixed, the one with the lower T1 level Triplet excitation level of the compound (T H(edge) ) supports the lifespan of such light-emitting devices The inventors considered this arrangement.

[0035] First, the T of the host material where energy transfer takes place. H(edge) and guest material T D(e dge) Energy difference (T H(edge) -T D(edge) External quantum based on the value of ) Regarding the impact on efficiency, as shown in Example 1, the phosphorescence spectra of multiple host materials and From the absorption spectra of the guest material, T H(edge) and T D(edge) each We then calculated the normalized external quantum efficiency based on the values ​​of the reference device, as shown in Figure 2. The above energy difference (T H(edge) -T D(edge) Regardless of the value of ), they are roughly the same. The result was that there is a certain value. Therefore, regarding the luminescence efficiency, the T of the host material H(edge ) The influence of its position can be said to be small.

[0036] However, the lifespan of the light-emitting device is only indicated by a number in Figure 1. Of the light-emitting devices, as shown by light-emitting device 6 (plot 6 in Figure 1), triplet When excitation energy is transferred endothermally, the lifetime decreases and reliability worsens. Meanwhile, light-emitting device 4 (plot 4 in Figure 1), light-emitting device 5 (plot in Figure 1) 5) shows a dramatic improvement in lifespan, exceeding that of the reference device (Ref.). Thus, T H(edge) -T D(edge) It is not greater than or equal to 0, but rather a certain degree One of the key components of this invention is that the lifespan cannot be ensured unless the value is positive. In other words, from Figure 1, the necessary condition is T H(edge) -T D(edge) The value is 0.0 It can be concluded that it is 7eV or greater. H(edge)-T D(edge) Up to However, as can be seen from Examples 3 and 4 described later, the lower limit is approximately +0.2eV, i.e., 0.2 Since a long lifespan is achieved at 7 eV or less, the limit was set at 0.27 eV or less.

[0037] Here, T H(edge) -T D(edge) Even if the value is 0.07eV or higher, Reference device, light-emitting device 3, and light-emitting device, rather than device 4 and light-emitting device 5 The lifespan of device 7 is deteriorating. These devices are experiencing reverse intersystem crossing in the host material. It's getting cheaper (S' H(edge) -T H(edge) (The voltage is less than 0.2 eV). Based on these results, assuming that the lifetime is reduced in cases where the effect of reverse interterm crossing exists, S' H( edge) -T H(edge) A condition was set that the voltage must be 0.2 eV or higher. Also, the actual In Example 3, S' H(edge) -T H(edge) Even if the value is around 0.4eV, Since lifespan has been obtained, S' H(edge) -T H(edge) The upper limit is 0.5eV and In other words, conditions were obtained in which reverse intersystem crossing in the host material is less likely to occur and a long lifespan can be obtained. Then, ΔE s’t =S' H(edge) -T H(edge) 0.2eV to 0.5eV The following range was defined. These conditions were defined as parameters for obtaining a long-life light-emitting device. Ta.

[0038] Furthermore, in the reference device, T is greater than the inverse intersystem crossover of the host material. H(edge) -T D (edge) It is also possible that it is controlled by the upper limit, H(edge)-T D(edge) The preferred upper limit is 0.17 eV.

[0039] In summary, one aspect of the present invention is a light-emitting device in which the host material in the light-emitting layer T H(edge) and guest material T D(edge) Energy difference (T H(edge) -T D(edge) The value of ) is 0.07 eV or more and 0.27 eV or less, preferably 0.07 In addition to the condition that the S' of the host material is in the range of eV to 0.17eV, H(ed ge) and host material T H(edge) Energy difference (S' H(edge) -T H( edge) The light-emitting device is one in which the value of ) is in the range of 0.2eV to 0.5eV. .

[0040] The above conditions can be expressed by the following equations (1) and (2). However, T H( edge) -T D(edge) If you place more emphasis on the upper limit, then consider equation (1). The condition in equation (3) is more preferable.

[0041]

number

[0042] Therefore, one aspect of the present invention is a light-emitting device having an EL layer between a pair of electrodes, and the EL layer is , has a light-emitting layer, the light-emitting layer has a first organic compound, a second organic compound, and a light-emitting substance and, of the T1 levels of the first organic compound or the T1 levels of the second organic compound, The lower T1 level of the Ghee level (T H(edge)), and the T1 level (T D(edge) ) satisfies the above formula (1), and the first organic compound and the second organic compound S1 level (S' H(edge) ) and, T H(edge) The difference is, This is a light-emitting device that satisfies the above formula (2). Note that the first organic compound and the second organic compound This will include cases where the compound is a combination that forms an excited complex.

[0043] However, T in equations (1) and (2) above H(edge) The light-emitting layer uses a host material. The phosphorescence spectra of the first organic compound and the second organic compound contained therein on the short wavelength side This refers to the lower energy T1 level among the T1 levels derived from the light-emitting edge. , T D(edge) The T1 level derived from the absorption edge of the absorption spectrum of the luminescent material is To point. Also, S' H(edge) The first organic compound and the second organic compound are This refers to the S1 level derived from the emission edge at the short wavelength end of the fluorescence spectrum of the mixed materials. These specific examples will be described in detail in Example 1.

[0044] (Embodiment 2) In this embodiment, a light-emitting device, which is one aspect of the present invention, will be described with reference to Figure 8.

[0045] ≪Structure of a light-emitting device≫ Figure 8 shows an example of a light-emitting device having an EL layer including a light-emitting layer between a pair of electrodes. It has a structure in which an EL layer 103 is sandwiched between the first electrode 101 and the second electrode 102. Furthermore, the EL layer 103, for example, when the first electrode 101 is the anode, contains holes. ) Injection layer 111, hole transport layer 112, light-emitting layer 113, electron transport layer 114, electron The injection layer 115 has a structure in which it is sequentially stacked as a functional layer. The structure of the electrode has multiple EL layers formed by sandwiching a charge generation layer between a pair of electrodes. Light-emitting devices that enable low-voltage operation by using a tandem structure, and a pair of electric By forming a microcavity structure between the poles, the optical properties are improved. Light-emitting devices such as the above are also included as one embodiment of the present invention. The charge generation layer is the first When a voltage is applied to electrode 101 and the second electrode 102, electrons are transferred to one of the adjacent EL layers. It has the function of injecting and then injecting holes into the other EL layer.

[0046] Furthermore, at least one of the first electrode 101 and the second electrode 102 of the above-mentioned light-emitting device is transparent The electrodes are photosensitive (transparent electrodes, semi-transparent / semi-reflective electrodes, etc.). In the case of transparent electrodes, the transmittance of visible light through the transparent electrode shall be 40% or higher. In the case of radiation electrodes, the reflectance of visible light for semi-transmitting and semi-reflective electrodes is preferably between 20% and 80%. The resistivity of these electrodes shall be between 40% and 70%. -2 Ωcm The following is preferable:

[0047] Furthermore, in the light-emitting device according to one aspect of the present invention described above, the first electrode 101 and the second If one of the electrodes 102 is a reflective electrode (reflective electrode), then the reflective electrode The visible light reflectance is 40% to 100%, preferably 70% to 100%. Furthermore, this electrode has a resistivity of 1 × 10⁻⁶. -2 It is preferable to keep it below Ωcm.

[0048] <First electrode and second electrode> The material used to form the first electrode 101 and the second electrode 102 is the same as the material used to form both electrodes as described above. If the requirements can be met, the following materials can be used in appropriate combinations. For example Metals, alloys, electrically conductive compounds, and mixtures thereof can be used as appropriate. Specifically, In-Sn oxide (also called ITO), In-Si-Sn oxide (IT Examples include SO (also known as In-Zn oxide) and In-W-Zn oxide. In addition, A Titanium (Al), Titanium (Ti), Chromium (Cr), Manganese (Mn), Iron (Fe), Cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), Indium (In), Tin (Sn), Molybdenum (Mo), Tantalum (Ta), Tungsten Ten (W), Palladium (Pd), Gold (Au), Platinum (Pt), Silver (Ag), Yttrium Metals such as chromium (Y), neodymium (Nd), and alloys containing these in appropriate combinations are used. It is also possible that there are other elements belonging to Group 1 or Group 2 of the periodic table that are not listed above. Element (for example, lithium (Li), cesium (Cs), calcium (Ca), strontium Rare earth metals such as syrup (Sr), europium (Eu), and ytterbium (Yb), and Alloys containing these elements in appropriate combinations, as well as graphene and other materials, can be used.

[0049] These electrodes can be fabricated using sputtering or vacuum deposition methods.

[0050] <Hole injection layer> The hole injection layer 111 injects holes from the first electrode 101, which is the anode, into the EL layer 103. This is the injection layer, and it contains organic acceptor materials or materials with high hole injection potential.

[0051] Organic acceptor materials are those whose LUMO level value and HOMO level value are close to those of other organic compounds. By separating charge between the organic compound and the material, holes are generated in the organic compound. It is a material that can do that. Therefore, as an organic acceptor material, quinodimethane derivatives and Electron-withdrawing groups (halogen groups and cyanoacrylates) such as chloranil derivatives and hexaazatriphenylene derivatives Compounds having an ano group can be used. For example, 7,7,8,8-tetracyano -2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), 3,6-di Fluoro-2,5,7,7,8,8-hexacyanoquinodimethane, chloranil, 2,3, 6,7,10,11-Hexacyano-1,4,5,8,9,12-Hexazatripheni Len (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano- Naphthoquinodimethane (abbreviation: F6-TCNNQ), etc., can be used. Among acceptor materials, HAT-CN in particular has high acceptor properties, and its film quality is affected by heat. It is suitable because it is stable. In addition, [3]radialene derivatives have very good electron-accepting properties. It is preferable because it is high, specifically α,α',α''-1,2,3-cyclopropane Redentris [4-Cyano-2,3,5,6-Tetrafluorobenzeneacetonitrile] α,α',α''-1,2,3-cyclopropanetriylidentris[2,6-diclo [Ro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], α, α',α''-1,2,3-cyclopropanetriylidentris[2,3,4,5,6- Pentafluorobenzeneacetonitrile and the like can be used.

[0052] Furthermore, materials with high hole injection potential include molybdenum oxide, vanadium oxide, and ruthenium. Examples include transition metal oxides such as tungsten oxide and manganese oxide. Other types of phthalocyanines include phthalocyanine (abbreviated as H2Pc) and copper phthalocyanine (abbreviated as CuPc). Cyanine compounds, etc., can be used.

[0053] In addition to the above materials, a low molecular weight compound, 4,4',4''-tris(N,N-diphthol Phenylamino)triphenylamine (abbreviation: TDATA), 4,4',4''-Tris[ N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: MTD) ATA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamine [N]biphenyl (abbreviation: DPAB), 4,4'-bis(N-{4-[N'-(3-methyl Phenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviated) Name: DNTPD), 1,3,5-Tris[N-(4-diphenylaminophenyl)-N- Phenylaminobenzene (abbreviation: DPA3B), 3-[N-(9-phenylcarbazo [Lu-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPC) A1) 3,6-bis[N-(9-phenylcarbazole-3-yl)-N-phenyl Mino]-9-phenylcarbazole (abbreviation: PCzPCA2), 3-[N-(1-naphthyl [Lu)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole Aromatic amine compounds such as PCzPCN1 (abbreviated as PCzPCN1) can be used.

[0054] Furthermore, polymer compounds (oligomers, dendrimers, polymers, etc.), such as poly(N-vinyl) Lucarbazole (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: P VTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl] [Nyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), Poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine Poly(TPD), etc., can be used. Alternatively, poly(3,4-ethylene) Dioxythiophene / poly(styrene sulfonic acid) (abbreviation: PEDOT / PSS), High-molecular-weight nitrates to which acids such as polyaniline / poly(styrene sulfonic acid) (PAni / PSS) have been added. Subsidiary compounds, etc., can also be used.

[0055] Furthermore, materials with high hole injection potential include hole transport materials and acceptor materials (electron acceptors). Composite materials containing (accepting materials) can also be used. In this case, the acceptor material provides a positive result. Electrons are extracted from the pore transport material, generating holes in the hole injection layer 111, and the hole transport layer 11 Holes are injected into the light-emitting layer 113 via 2. The hole injection layer 111 is a hole transport material. It may also be formed as a single layer of a composite material containing a material and an acceptor material (electron-accepting material). However, if hole transport material and acceptor material (electron-accepting material) are stacked in separate layers... It may also be formed in layers.

[0056] Furthermore, as a hole transport material, 10 -6 cm 2 A substance having a hole mobility of / Vs or higher Preferred. However, if the material has higher hole transport capabilities than electron transport, other materials can be used. It is possible.

[0057] As the hole transporting material, hole transporting materials with high hole transporting ability such as π - electron - rich heteroaromatic compounds (e.g., carbazole derivatives and furan derivatives) and aromatic amines (compounds having an aromatic amine skeleton) are preferred.

[0058] In addition, as the carbazole derivatives (compounds having a carbazole skeleton), bicarba zole derivatives (e.g., 3,3’ - bicarbaazole derivatives), aromatic amines having a carbazolyl group, etc. can be mentioned.

[0059] Further, as the bicarbaazole derivatives (e.g., 3,3’ - bicarbaazole derivatives), specifically, 3,3’ - bis(9 - phenyl - 9H - carbazole) (abbreviation: PCCP ), 9,9’ - bis(1,1’ - biphenyl - 4 - yl) - 3,3’ - bi - 9H - carbazole, 9,9’ - bis(1,1’ - biphenyl - 3 - yl) - 3,3’ - bi - 9H - carbazole, 9 - (biphenyl - 3 - yl) - 9’ - (biphenyl - 4 - yl) - 9H,9’H - 3,3’ - bicarbaazole (abbreviation: mBPCCBP), 9 - (2 - naphthyl) - 9’ - phenyl - 9H,9’H - 3,3’ - bicarbaazole (abbreviation : βNCCP), etc. can be mentioned.

[0060] In addition, as the aromatic amine having a carbazolyl group, specifically, 4 - phenyl - 4’ - (9 - phenyl - 9H - carbazol - 3 - yl) triphenylamine (abbreviation: P CBA1BP), N - (4 - biphenyl) - N - (9,9 - dimethyl - 9H - fluorene - 2 - yl) - 9 - phenyl - 9H - carbazol - 3 - amine (abbreviation: PCBiF), N - (1,1’ - biphenyl - 4 - yl) - N - [4 - (9 - phenyl - 9H - carbazol -yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation : PCBBiF), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol- -3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl) -4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carb azole-3-yl)triphenylamine (abbreviation: PCBNBB), 4-phenyldiphe nyl-(9-phenyl-9H-carbazol-3-yl)amine (abbreviation: PCA1BP) , N,N'-bis(9-phenylcarbazol-3-yl)-N,N'-diphenylben zene-1,3-diamine (abbreviation: PCA2B), N,N',N''-triphenyl-N, N',N''-tris(9-phenylcarbazol-3-yl)benzene-1,3,5- triamine (abbreviation: PCA3B), 9,9-dimethyl-N-phenyl-N-[4-(9- phenyl-9H-carbazol-3-yl)phenyl]fluorene-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl phenyl]spiro-9,9'-bifluorene-2-amine (abbreviation: PCBASF), 3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phe nylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarb azole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCz PCA2), 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl )amino]-9-phenylcarbazole (abbreviation: PCzPCN1), 3-[N-(4-di Phenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA1), 3,6-bis[N-(4-diphenylaminophenyl)-N-phenyl Luamino]-9-phenylcarbazole (abbreviation: PCzDPA2), 3,6-bis[N- (4-diphenylaminophenyl)-N-(1-naphthyl)amino]-9-phenylcal Bazole (abbreviation: PCzTPN2), 2-[N-(9-phenylcarbazole-3-yl) )-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: PCASF), N- [4-(9H-carbazole-9-yl)phenyl]-N-(4-phenyl)phenyl Dilin (abbreviation: YGA1BP), N,N'-bis[4-(carbazole-9-yl)fer [Nyl]-N,N'-diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviation) :YGA2F), 4,4',4''-Tris(carbazole-9-yl)triphenyl Examples include Min (abbreviated as TCTA).

[0061] In addition to the above, 3-[4-(9-phenanthryl) -phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPPn), 3-[4-( 1-Naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 1,3-Bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-Di(N-carbazolyl)benzene Bazolyl biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl) -9-phenylcarbazole (abbreviation: CzTP), 1,3,5-tris[4-(N-Cal [Bazolyl)phenyl]benzene (abbreviation: TCPB), 9-[4-(10-phenyl-9- Examples include anthracenyl)phenyl]-9H-carbazole (abbreviated as CzPA).

[0062] Furthermore, the above furan derivatives (compounds having a furan skeleton) specifically include 4,4' ,4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: D BT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluorene -9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4 -(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzo Compounds containing a thiophene skeleton, such as Ophene (abbreviation: DBTFLP-IV), 4,4' ,4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF) 3P-II), 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl Examples include phenyl dibenzofuran (abbreviation: mmDBFFLBi-II).

[0063] Furthermore, the above aromatic amine specifically refers to 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'-bis[N-(spiro-9,9'-bifluorene -2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), 4-phenyl-4 -(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) , 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviated) Name: mBPAFLP), 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-fluorene-7-yl}phenylamine (abbreviation: DFLADFL), N-(9,9-dimethyl-2-diphenylamino-9H-fluorene-7-yl)diphenylamine (abbreviation: DPNF), 2-[N-(4-diphenylaminophenyl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: DPASF), レン-2-イル)アミノ]-9H-フルオレン-7-イル}フェニルアミン(略称:DF LADFL), N-(9,9-dimethyl-2-diphenylamino-9H-fluorene-7 -yl)diphenylamine (abbreviation: DPNF), 2-[N-(4-diphenylaminophenyl ニル)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: DPASF), 2,7-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-spiro -9,9'-bifluorene (abbreviation: DPA2SF), 4,4',4''-tris[N-( 1-naphthyl)-N-phenylamino]triphenylamine (abbreviation: 1'-TNATA) , 4,4',4''-tris(N,N-diphenylamino)triphenylamine (abbreviation: [[ID=ID=18]] TDATA), 4,4',4''-tris[N-(3-methylphenyl)-N-phenyl amino]triphenylamine (abbreviation: m-MTDATA), N,N'-di(p-tolyl) -N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'- bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation : DPAB), N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl} -N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DN TPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenyl amino]benzene (abbreviation: DPA3B), etc. can be mentioned.

[0064] As the hole transporting material, poly(N-vinylcarbazole) (abbreviation: PVK), poly(4 -Vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4- (4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)meth [Crylamide] (abbreviation: PTPDMA), poly[N,N'-bis(4-butylphenyl) Polymerization of -N,N'-bis(phenyl)benzidine (abbreviation: Poly-TPD), etc. A blended mixture can also be used.

[0065] However, the hole transport material is not limited to the above, and may be one or more of various known materials. They may be used in combination as a hole-transporting material.

[0066] The acceptor material used in the hole injection layer 111 is a material from Group 4 of the periodic table. Oxides of metals belonging to Group 8 can be used. Specifically, molybdenum oxide, oxide Vanadium, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide Rhenium oxide is one example. In particular, molybdenum oxide is stable even in the atmosphere and absorbs It is preferable because it has low moisture content and is easy to handle. In addition, the above-mentioned organic acceptor materials can be used. It is also possible.

[0067] The hole injection layer 111 can be formed using various known film deposition methods, for example For example, it can be formed using the vacuum deposition method.

[0068] <Hole transport layer> The hole transport layer 112 receives holes injected from the first electrode 101 by the hole injection layer 111. This layer transports holes to the light-emitting layer 113. The hole transport layer 112 contains a hole-transporting material. It is a layer. Therefore, the hole transport layer 112 contains holes that can be used in the hole injection layer 111. Transportable materials can be used.

[0069] Furthermore, in a light-emitting device according to one aspect of the present invention, the same organic compound as the hole transport layer 112 It is preferable to use the same organic compound in the light-emitting layer 113. By using a composite material, the transport of holes from the hole transport layer 112 to the light-emitting layer 113 is performed efficiently. This is for the purpose of obtaining it.

[0070] <Luminous layer> The light-emitting layer 113 is a layer containing a light-emitting material. There are no particular limitations on the photomaterials, as long as they convert singlet excitation energy into emission in the visible light region. Using photochemicals, or light-emitting materials that convert triplet excitation energy into visible light emission. It can also emit light in colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red. The substances exhibiting these characteristics can be used as appropriate.

[0071] In a light-emitting device according to one aspect of the present invention, the light-emitting layer 113 is a light-emitting substance (guest material) and has one or more types of organic compounds (host material, etc.). However, the organic compounds used here The biocompound (host material, etc.) has a larger energy gap than the luminescent material (guest material). It is preferable to use a material with a large energy gap. As for organic compounds (host materials, etc.), the hole transport layer 112 described above can be used. Pore ​​transport materials, electron transport materials that can be used in the electron transport layer 114 described later, etc. Examples include mechanical compounds.

[0072] Specifically, the light-emitting layer 113 contains a first organic compound, a second organic compound, and a light-emitting material. It possesses. The first organic compound is preferably an electron transport material, and the second organic compound is A hole-transporting material is preferred. A phosphorescent material is preferred as the light-emitting substance.

[0073] Another configuration of the light-emitting layer 113 is to have multiple light-emitting layers containing different light-emitting materials. This results in a configuration that exhibits different emission colors (for example, by combining emission colors that are complementary to each other). The resulting white light emission may also be used. In addition, one light-emitting layer may have multiple different light-emitting materials. The structure is also good.

[0074] Examples of the above-mentioned luminescent materials include the following:

[0075] Examples of light-emitting materials that convert singlet excitation energy into light include fluorescent materials. Examples include pyrene derivatives, anthracene derivatives, triphenylene derivatives, Fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives Conductors, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidines Examples include derivatives, phenanthrene derivatives, naphthalene derivatives, etc. In particular, pyrene derivatives It is preferable because it has a high luminescence quantum yield. A specific example of a pyrene derivative is N,N'-bis( 3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluorene-9- Iyl(phenyl)pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluorene-9- [Iyl]phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N' -Bis(dibenzofuran-2-yl)-N,N'-diphenylpyrene-1,6-diamine (Abbreviation: 1,6FrAPrn), N,N'-bis(dibenzothiophen-2-yl)-N ,N'-diphenylpyrene-1,6-diamine (abbreviation: 1,6ThAPrn), N,N' -(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d] [Furan)-6-amine](abbreviation: 1,6BnfAPrn), N,N'-(pyrene-1,6 -Diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-8-ami [n] (abbreviation: 1,6BnfAPrn-02), N,N'-(pyrene-1,6-diyl)bi Su[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine]( Examples include abbreviations such as 1,6BnfAPrn-03).

[0076] In addition, 5,6-bis[4-(10-phenyl-9-antryl)phenyl]-2, 2'-Bipyridine (abbreviation: PAP2BPy), 5,6-Bis[4'-(10-phenyl- 9-Anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2B) Py), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N' -Diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-Cal Bazole-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (Abbreviation: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-di Phenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-di Phenyl-N-[4-(10-phenyl-9-antryl)phenyl]-9H-carbazo 4-(10-phenyl-9-anthryl)-4 (abbreviation: PCAPA), 4-(10-phenyl-9-anthryl)-4 '-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PC) BAPA), 4-[4-(10-phenyl-9-antryl)phenyl]-4'-(9- Phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBAPBA) ), perylene, 2,5,8,11-tetra(tert-butyl)perylene (abbreviation: TBP) ), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1- Phenylene)bis[N,N',N'-triphenyl-1,4-phenylenediamine](abbreviated) Name: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-A Nantrillyl]phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA), N -[4-(9,10-diphenyl-2-antryl)phenyl]-N,N',N'-triphenyl Phenyl-1,4-phenylenediamine (abbreviated as 2DPAPPA), etc., can be used. ru.

[0077] Furthermore, examples of light-emitting materials that convert triplet excitation energy into light include phosphorescent materials. The quality (phosphorescent material) and thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) materials are being mentioned. It can be done.

[0078] Examples of phosphorescent materials include organometallic complexes, metal complexes (platinum complexes), and rare earth metal complexes. These materials exhibit different emission colors (emission peaks), so they can be selected as needed. Select and use as appropriate.

[0079] It exhibits a blue or green color, and the peak wavelength of its emission spectrum is between 450 nm and 570 nm. Examples of phosphorescent materials include the following:

[0080] For example, tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl )-4H-1,2,4-triazol-3-yl-κN 2 phenyl-κC}iridium (III)(abbreviation: [Ir(mpptz-dmp)3]), tris(5-methyl-3,4 -diphenyl-4H-1,2,4-triazolato)iridium(III)(abbreviation: [Ir (Mptz)3]), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl yl-;4H-1,2,4-triazolato]iridium(III)(abbreviation: [Ir(iPrp tz-3b)3]), tris[3-(5-biphenyl)-5-isopropyl-4-phenyl yl-4H-1,2,4-triazolato]iridium(III)(abbreviation: [Ir(iPr5 btz)3]), such as organometallic complexes having a 4H-triazole skeleton, tris[3- methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato iridium(III)(abbreviation: [Ir(Mptz1-mp)3]), tris(1-methyl yl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(II I)(abbreviation: [Ir(Prptz1-Me)3]) having a 1H-triazole skeleton , fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl yl-1H-imidazole]iridium(III)(abbreviation: [Ir(iPrpmi)3 ), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f] phenanthridinato]iridium(III)(abbreviation: [Ir(dmpimpt-Me)3 ) such as organometallic complexes having an imidazole skeleton, bis[2-(4’,6’-diflu orophenyl)pyridinato-N,C 2’Iridium(III) tetrakis(1-pyrazo Lyl) Borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)p Riginato-N,C 2’ Iridium(III) picolinate (abbreviation: Firpic), S{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinate-N,C 2’ Iridium(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]) , bis[2-(4',6'-difluorophenyl)pyridinate-N,C 2’ ]iridium (III) Acetylacetonate (abbreviation: Fir(acac)) has an electron-withdrawing group Examples include organometallic complexes using phenylpyridine derivatives as ligands.

[0081] It exhibits a green or yellow color, and the peak wavelength of its emission spectrum is between 495 nm and 590 nm. Examples of phosphorescent materials include the following:

[0082] For example, Tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation) :[Ir(mppm)3]), Tris(4-t-butyl-6-phenylpyrimidinato) Lydium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonate) Iridium(III) (abbreviation: [Ir(m ppm)2(acac)]), (acetylacetonato)bis(6-tert-butyl-4) -Phenylpyrimidina) Iridium(III) (Abbreviation: [Ir(tBuppm)2(a (cac)), (acetylacetonato)bis[6-(2-norbornyl)-4-phenyl [Pyrimidinato] Iridium(III) (Abbreviation: [Ir(nbppm)2(acac)]) , (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenyl pyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm)2(acac) ), (acetylacetonato)bis{4,6-dimethyl-2-[6-(2,6-dimethyl phenyl)-4-pyrimidinyl-κN 3 phenyl-κC}iridium(III) (abbreviation : [Ir(dmppm-dmp)2(acac)]), (acetylacetonato)bis(4 ,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2( acac)]), organometallic iridium complexes having a pyrimidine skeleton such as (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)]), organometallic iridium complexes having a pyrazine skeleton such as tris(2-phenylpyridinato-N,C )iridium(III) 2’ (abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinato-N,C )iridium(III) acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), bis 2’ (benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [I r(bzq)2(acac)]), tris(benzo[h]quinolinato)iridium(II I) (abbreviation: [Ir(bzq)3]), tris(2-phenylquinolinato-N,C 2’ ( iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinolinato- 2’ ), and bis(2-phenylquinolinato- N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(a cac)]), bis[2-(2-pyridinyl-κN)phenyl-κC][2-(4-phenyl [Ir(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir( ppy)2(4dppy)]), bis[2-(2-pyridinyl-κN)phenyl-κC] [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC] Organometallic iridium complex having a pyridine skeleton, bis(2,4-diphenyl-1,3-o Xazolato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: [Ir( dpo)2(acac)]), bis{2-[4'-(perfluorophenyl)phenyl] Pyridinate-N,C 2’ Iridium(III) acetylacetonate (abbreviation: [Ir( p-PF-ph)2(acac)]), bis(2-phenylbenzothiazolat-N,C 2 ’ Iridium(III) acetylacetonate (abbreviation: [Ir(bt)2(acac) In addition to organometallic complexes such as ]), tris(acetylacetonato)(monophenanthroline) Rare earth golds such as terbium(III) (abbreviation: [Tb(acac)3(Phen)]) Examples include genus complexes.

[0083] It exhibits a yellow or red color, and the peak wavelength of its emission spectrum is between 570 nm and 750 nm. Examples of phosphorescent materials include the following:

[0084] For example, (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrim [Dinato] Iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), Su[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)yl Zium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), (Dipivaloylmethic acid) Thanato)bis[4,6-di(naphthalene-1-yl)pyrimidinato]iridium(III Organic compounds having a pyrimidine skeleton, such as (abbreviation: [Ir(d1npm)2(dpm)]) Metal complex, (acetylacetonato)bis(2,3,5-triphenylpyradinato)iridi Um(III) (abbreviation: [Ir(tppr)2(acac)]), Bis(2,3,5-) Iridium(III) (dipivaloylmethanato) (abbreviation: [Ir (tppr)2(dpm)]), bis{4,6-dimethyl-2-[3-(3,5-dimethyl-2)} [Phenyl-5-phenyl-2-pyradinyl-κN]phenyl-κC}(2,6-dimethyl Chil-3,5-heptandionato-κ 2 O,O') Iridium(III) (Abbreviation: [Ir (dmdppr-P)2(dibm)]), bis{4,6-dimethyl-2-[5-(4- Cyano-2,6-dimethylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazi [Nyl-κN]phenyl-κC}(2,2,6,6-tetramethyl-3,5-heptanediol) Nato-κ 2 O,O') Iridium(III) (Abbreviation: [Ir(dmdppr-dmCP) 2(dpm)]), (acetylacetonato)bis[2-methyl-3-phenylquinoxali Nato-N,C 2’ Iridium(III) (abbreviation: Ir(mpq)2(acac)) (Acetylacetonato)bis(2,3-diphenylquinoxalinato-N,C 2’ ) Iri Dium(III) (abbreviation: [Ir(dpq)2(acac)]), (acetylacetonate) )Bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) Organometallic compounds with a pyrazine skeleton, such as (abbreviation: [Ir(Fdpq)2(acac)]) Complexes, or Tris(1-phenylisoquinolinato-N,C) 2’ ) Iridium (III) (abbreviated) Name: [Ir(piq)3]), bis(1-phenylisoquinolinato-N,C 2’ ) Iridi Um(III)acetylacetonate (abbreviation: [Ir(piq)2(acac)]), S[4,6-dimethyl-2-(2-quinolinyl-κN)phenyl-κC](2,4-phenyl Tangionato-κ 2 O,O') Iridium(III) (Abbreviation: [Ir(dmpqn)2( Organometallic complexes having a pyridine skeleton, such as acac), 2,3,7,8,12,1 3,17,18-Octaethyl-21H,23H-Porphyrin Platinum(II) (Abbreviation: [ Platinum complexes such as PtOEP, Tris(1,3-diphenyl-1,3-propanediol) Nat(monophenanthroline) europium(III) (abbreviation: [Eu(DBM)3( Phen)), Tris[1-(2-tenoyl)-3,3,3-trifluoroacetonate ](monophenanthroline) europium(III) (abbreviation: [Eu(TTA)3(Ph Examples include rare earth metal complexes such as (en)).

[0085] Furthermore, as the first organic compound indicated above as being usable in the light-emitting layer 113, Electron-transporting materials are preferred. Therefore, the π-electron-deficient heteroaromatic compound is preferred. This is preferable. Specifically, it is preferable to have a pyridine ring, diazine ring, or triazine ring structure. This lowers the LUMO level, making it easier to transport electrons. For example, 4,6-bis[3 -(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm) , 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6m DBTP2Pm-II), 4,6-bis[3-(9H-carbazol-9-yl)pheni Pyrimidine derivatives such as [4,6mCzP2Pm]pyrimidine (abbreviation: 4,6mCzP2Pm), 2-{4-[3 -(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl] Phenyl-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn) ,9-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]- 9'-Phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02) ) and other triazine derivatives, 3,5-bis[3-(9H-carbazole-9-yl)phenyl [Lu]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)f Examples include pyridine derivatives such as [phenyl]benzene (abbreviation: TmPyPB). Among the deficient heteroaromatic compounds, in particular, the aromatic ring is fused to the furan ring of the phlodiazine skeleton. Organic compounds having the following structure are preferred, and specific examples are shown below. The transportable material can also be used in the electron transport layer 114 described later.

[0086] [ka]

[0087] On the other hand, the second organic compound shown above as being usable in the light-emitting layer 113 is Therefore, hole-transporting materials are preferred. Thus, π-electron-rich heteroaromatic compounds (e.g., CAL) (Bazole derivatives and furan derivatives) and aromatic amines (compounds having an aromatic amine skeleton), etc. Materials with high hole transport properties are preferred.

[0088] However, if the HOMO level of the second organic compound is too shallow, the excited complex with the first organic compound will form. form and S H(edge) This leads to a problem where the coefficient becomes smaller, making it easier for inverse interterm crossing to occur. Therefore, among those mentioned above, carbazole derivatives with a relatively deep HOMO level are preferred. As for carbazole derivatives (compounds having a carbazole skeleton), bicarbazole derivatives The conductor (e.g., particularly 3,3'-bicarbazole derivatives) has high stability, which is preferable. As mentioned above, in order to avoid making the HOMO level too shallow, the above carbazole derivative is Preferably, it does not have an aromatic amine skeleton (specifically, a triarylamine skeleton).

[0089] Furthermore, the above bicarbazole derivatives (for example, 3,3'-bicarbazole derivatives) are Specifically, 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP) ), 9,9'-bis(1,1'-biphenyl-4-yl)-3,3'-bi-9H-carb Zol, 9,9'-bis(1,1'-biphenyl-3-yl)-3,3'-bi-9H-ka Luvazole, 9-(1,1'-biphenyl-3-yl)-9'-(1,1'-biphenyl -4-yl)-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCBP), 9 -(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation) Examples include βNCCP.

[0090] In addition to the above organic compounds, organic compounds that can be used in the light-emitting layer 113 include From the perspective that combination with luminescent materials (fluorescent materials, phosphorescent materials) is preferable. The following organic compounds are examples (some of which overlap with the above):

[0091] When the light-emitting substance is a fluorescent substance, the preferred organic compound is one that combines well with the fluorescent substance. Examples include anthracene derivatives, tetracene derivatives, phenanthrene derivatives, and pyrene derivatives. Examples include condensed polycyclic aromatic compounds such as chrysene derivatives and dibenzo[g,p]chrysene derivatives. It can be done.

[0092] Specific examples of organic compounds that are preferred in combination with fluorescent substances include 9-phenyl Lu-3-[4-(10-phenyl-9-antryl)phenyl]-9H-carbazole ( Abbreviation: PCzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-antri [Phenyl]-9H-carbazole (abbreviation: DPCzPA), 3-[4-(1-naphthyl] [Phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9,10- Diphenylanthracene (abbreviation: DPAnth), N,N-diphenyl-9-[4-(1 0-phenyl-9-antryl)phenyl]-9H-carbazole-3-amine (abbreviation: CzA1PA), 4-(10-phenyl-9-anthryl)triphenylamine (abbreviation: DPhPA), YGAPA, PCAPA, N,9-diphenyl-N-{4-[4-(10 -phenyl-9-antryl)phenyl]phenyl}-9H-carbazole-3-amine (Abbreviation: PCAPBA), N-(9,10-diphenyl-2-anthryl)-N,9-di Phenyl-9H-carbazole-3-amine (abbreviation: 2PCAPA), 6,12-dimeth Xy-5,11-diphenylchrysene, N,N,N',N',N'',N'',N''' ,N'''-Octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetra Amine (abbreviation: DBC1), 9-[4-(10-phenyl-9-anthracenyl)phen [L]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-an [Tolyl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA ), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]-benzo[b]na Futo[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-{4-( 9-phenyl-9H-fluoren-9-yl)-biphenyl-4'-yl}-anthrace 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: FLPPA), (Abbreviation: DPPA), 9,10-di(2-naphthyl)anthracene (Abbreviation: DNA), 2 -tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDN) A) 9,9'-biantril (abbreviation: BANT), 9,9'-(stilbene-3,3' -Diphenanthrene (abbreviation: DPNS), 9,9'-(Stilbene-4,4'- Diyl)diphenanthrene (abbreviation: DPNS2), 1,3,5-tri(1-pyrenyl)be Nzen (abbreviation: TPB3), 5,12-diphenyltetracene, 5,12-bis(bife Examples include yl-2-yltetracene.

[0093] Furthermore, if the luminescent material is a phosphorescent material, the combination with the phosphorescent material is preferable. As for compounds, the triplet excitation energy of luminescent materials (the energy difference between the ground state and the triplet excited state) You should select an organic compound whose triplet excitation energy is greater than the energy difference. Multiple organic compounds (e.g., a first host material and a second host material) are used to form a complex. Using a host material (or host material and assist material, etc.) in combination with a light-emitting substance. If present, it is preferable to use these multiple organic compounds mixed with a phosphorescent substance. .

[0094] By using this configuration, the energy transfer from the excited complex to the luminescent material, called Ex, is achieved. Using TET (Exciplex-Triplet Energy Transfer) This allows for efficient emission. Furthermore, as a combination of multiple organic compounds, Compounds that readily form complexes are desirable, and compounds that readily accept holes (hole transport materials), It is particularly preferable to combine it with a compound that readily accepts electrons (electron transport material).

[0095] Furthermore, if the luminescent material is a phosphorescent material, the combination with the phosphorescent material is preferable. Examples of compounds (host material, assist material) include aromatic amines, carbazole derivatives, and di Benzothiophene derivatives, dibenzofuran derivatives, zinc and aluminum-based metal complexes, Xadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline Derivatives, dibenzoquinoxaline derivatives, pyrimidine derivatives, pyrazine derivatives, triazines Examples include derivatives, pyridine derivatives, bipyridine derivatives, phenanthroline derivatives, etc. .

[0096] Furthermore, specific examples of these include 2-(4-biphenylyl)-5-(4-tert-butyric acid). Ruphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-( p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (Abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2 -yl)phenyl]-9H-carbazole (abbreviation: CO11), 3-(4-biphenylyl )-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (Abbreviation: TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl) )-5-(4-biphenylyl)-1,2,4-triazole (abbreviation: p-EtTAZ), etc. Triazole derivatives, 2,2',2''-(1,3,5-benzenetriyl)tris( 1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzo Thiofen-4-yl)phenyl]-1-phenyl-1H-benzoimidazole (abbreviation: mDBTBIm-II), 4,4'-bis(5-methylbenzoxazol-2-yl) Stilbene (abbreviation: BzOs), vasophenanthroline (abbreviation: Bphen), vasocu Proin (abbreviation: BCP), 2,9-bis(naphthalene-2-yl)-4,7-diphen Lu-1,10-phenanthroline (abbreviation: NBphen), 2-[3-(dibenzothioff) [phenyl-4-yl]phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDB) q-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]di Benzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-( 9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxali n (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazol [Lu-9-yl]phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-I II) 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h] Noxaline (abbreviation: 7mDBTPDBq-II), and 6-[3-(dibenzothiophene -4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq- Examples include quinoxaline derivatives such as (II) and dibenzoquinoxaline derivatives.

[0097] Furthermore, 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviated) :4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]p Limidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carb Pyrimidines such as zole-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm) Derivatives, 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H- Carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine ( Abbreviation: PCCzPTzn), 9-[3-(4,6-diphenyl-1,3,5-triazine] -2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: Triazine derivatives such as mPCCzPTzn-02, 3,5-bis[3-(9H-carba Zole-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri Pyridine derivatives such as [3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB) These are some examples.

[0098] Also, poly(2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexyl Fluorene-2,7-diyl)-co-(pyridine-3,5-diyl)(abbreviation: PF- Py), poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2' Using polymer compounds such as (-bipyridine-6,6'-diyl) (abbreviation: PF-BPy) It is possible to stay there.

[0099] Furthermore, when multiple organic compounds are used in the light-emitting layer 113, two types of compounds that form the excitation complex are used. The first organic compound and the second organic compound may be used in combination with the luminescent substance. In this case, various organic compounds can be used in appropriate combinations, but the excitation complex To form a body, a compound that readily accepts holes (hole transport material) and a compound that accepts electrons are needed. It is particularly preferable to combine it with easily obtainable compounds (electron transport materials). For specific examples of transportable materials and electron transportable materials, use the materials shown in this embodiment. This configuration allows for high efficiency, low voltage, and long lifespan to be achieved simultaneously.

[0100] TADF materials are materials that can be converted from a triplet excited state to a singlet excited state by a small amount of thermal energy. It enables reverse intersystem crossing (op-conversion) and efficiently generates light (fluorescence) from the singlet excited state. It refers to materials that exhibit this phenomenon. Furthermore, the conditions under which thermally activated delayed fluorescence can be efficiently obtained are three The energy difference between the doublet excited level and the singlet excited level is 0 eV or more and 0.2 eV or less, preferably. One example is that the voltage is between 0 eV and 0.1 eV. Also, regarding delayed fluorescence in TADF materials... Light refers to emission that has a spectrum similar to ordinary fluorescence but with a significantly longer lifetime. Its lifespan is 10 -6 10 seconds or more, preferably 10 -3 It is more than a second.

[0101] Examples of TADF materials include fullerenes and their derivatives, and acridines such as proflavin. Examples include derivatives and eosin. Also, magnesium (Mg), zinc (Zn), cadmium Um (Cd), tin (Sn), platinum (Pt), indium (In), or palladium Examples of metal-containing porphyrins include those containing (Pd), etc. For example, protoporphyrin-tin fluoride complex (abbreviation: SnF2 (Proto IX)) Mesoporphyrin-tin fluoride complex (abbreviation: SnF2 (Meso IX)), hematopo Rufirin-tin fluoride complex (abbreviation: SnF2(Hemato IX)), copropolph Fluorine tetramethyl ester-tin fluoride complex (abbreviation: SnF2(Copro III- 4Me)), Octaethylporphyrin-tin fluoride complex (abbreviation: SnF2(OEP)) , Ethioporphyrin-tin fluoride complex (abbreviation: SnF2(Etio I)), Octae Examples include tilporphyrin-platinum chloride complex (abbreviated as PtCl2OEP).

[0102] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindoro[ 2,3-a]carbazole-11-yl)-1,3,5-triazine (abbreviation: PIC-T RZ), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-3-yl) Luvazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviated) Name: PCCzPTzn), 2-[4-(10H-phenoxazine-10-yl)phenyl ]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4 -(5-phenyl-5,10-dihydrophenazine-10-yl)phenyl]-4,5- Diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-di Methyl-9H-acridine-10-yl)-9H-xanthene-9-one (abbreviation: ACR) XTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl] Sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[A π electron peroxides such as clidine-9,9'-anthracene]-10'-one (abbreviated as ACRSA) Heterocyclic compounds having a superfluous heteroaromatic ring and a π-electron-deficient heteroaromatic ring may also be used.

[0103] Furthermore, in substances in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded, Both the donor properties of the electron-excess type heteroaromatic ring and the acceptor properties of the π-electron-deficient type heteroaromatic ring are strong. This is particularly preferable because it reduces the energy difference between the singlet excited state and the triplet excited state.

[0104] Furthermore, when using TADF materials, they can also be used in combination with other organic compounds. In particular, it can be combined with the host material, hole transport material, and electron transport material mentioned above, and is practical. An organic compound, which is one aspect of the present invention as shown in Application Form 1, is used as a host material for a TADF material. It is preferable to use it in this way.

[0105] Furthermore, the above materials may be used in combination with low molecular weight materials or polymer materials. Known methods (such as vacuum deposition, coating, or printing) can be used as appropriate.

[0106] <Electron transport layer> The electron transport layer 114 is injected from the second electrode 102 by the electron injection layer 115, which will be described later. This layer transports electrons to the light-emitting layer 113. The electron transport layer 114 is made of an electron-transporting material. This is a layer containing [a specific material]. The electron transport material used in the electron transport layer 114 is 1 × 10⁻¹⁶ -6 cm 2 / V A material having an electron mobility of s or higher is preferred. Furthermore, a material with higher electron transport than holes is preferred. If so, other materials can be used. Also, the electron transport layer 114 is a single layer. While this also works, device characteristics can be improved by using a stacked structure of two or more layers as needed. It can also be made to do so.

[0107] Organic compounds that can be used in the electron transport layer 114 include furans with a phlodiazine skeleton. Organic compounds having a structure in which an aromatic ring is condensed on a ring, metal complexes having a quinoline skeleton, benzo Metal complexes having a quinoline skeleton, metal complexes having an oxazole skeleton, thiazole skeleton In addition to metal complexes, etc., oxadiazole derivatives, triazole derivatives, imidazole derivatives Conductors, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline coordination Quinoline derivatives containing derivatives, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquino Xaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other nitrogen-containing compounds. Materials with high electron transport capabilities, such as π-electron-deficient heteroaromatic compounds containing heteroaromatic compounds (electron Transportable materials can be used.

[0108] A specific example of an electron-transporting material is 2-[3'-(dibenzothiophen-4-yl )Biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDB) q-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]di Benzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 5-[3-(4 ,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-7,7-dimethyl -5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn) ), 4-[3-(dibenzothiophen-4-yl)phenyl]-8-(naphthalene-2- Il)-[1]benzoflof[3,2-d]pyrimidine (abbreviation: 8βN-4mDBtPBf pm), 3,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzofl[ 2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-bis[3-(di [Benzothiophene-4-yl)phenyl]-[1]benzofloflo[3,2-d]pyrimidine (Abbreviation: 4,8mDBtP2Bfpm), 9-[(3'-dibenzothiophen-4-yl) )biphenyl-3-yl]naphtho[1',2':4,5]flo[2,3-b]pyrazine( Abbreviation: 9mDBtBPNfpr), 8-[3'-(dibenzothiophen-4-yl)(1 ,1'-biphenyl-3-yl)]naphtho[1',2':4,5]fl[3,2-d]pi Limidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2'-binaphthalene)-6- [Il]-4-[3-(dibenzothiophen-4-yl)phenyl-[1]benzofl[3 ,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), tris(8-k (Nolinolato)aluminum(III) (abbreviation: Alq3), tris(4-methyl-8-k (Norinolat)aluminum(III) (abbreviation: Almq3), bis(10-hydroxyb) (nzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2), bis(2-methyl- 8-Quinolinolato)(4-Phenylphenolato)aluminum(III) (Abbreviation: BAl q), bis(8-quinolinolato)zinc(II) (abbreviation: Znq), or other quinoline skeletons or A metal complex having a benzoquinoline skeleton, bis[2-(2-benzoxazolyl)phenol [T] Zinc (II) (abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenol [T] Zinc(II) (abbreviation: ZnBTZ), bis[2-(2-hydroxyphenyl)benzo Thiazolato] Zinc(II) (abbreviation: Zn(BTZ)2) and other oxazole skeletons or thia Examples include metal complexes having a zole skeleton.

[0109] In addition to metal complexes, oxadiazole derivatives such as PBD, OXD-7, and CO11, and T Triazole derivatives such as AZ, p-EtTAZ, TPBI, mDBTBIm-II, etc. Midazole derivatives (including benzimidazole derivatives) and oxazoles such as BzOs. Phenanthroline derivatives such as derivatives, Bphen, BCP, NBphen, and 2mDBT PDBq-II, 2mDBTBPDBq-II, 2mCzBPDBq, 2CzPDBq- Quinoxalines such as III, 7mDBTPDBq-II, and 6mDBTPDBq-II Derivatives, or dibenzoquinoxaline derivatives, such as 35DCzPPy, TmPyPB, etc. Zin derivatives, 4,6mPnP2Pm, 4,6mDBTP2Pm-II, 4,6mCzP2 Pyrimidine derivatives such as Pm, triazine derivatives such as PCCzPTzn and mPCCzPTzn-02 Derivatives can be used.

[0110] Furthermore, polymer compounds such as PPy, PF-Py, and PF-BPy can also be used.

[0111] <Electron injection layer> The electron injection layer 115 is a layer that enhances the efficiency of electron injection from the cathode, and the cathode material When comparing the value of the function with the LUMO level value of the material used in the electron injection layer 115, It is preferable to use a material with a small difference (0.5 eV or less). Therefore, electron injection layer 115 It contains lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), and Calcium sulfate (CaF2), 8-(quinolinolato)lithium (abbreviation: Liq), 2-( 2-Pyridyl)phenolatritium (abbreviation: LiPP), 2-(2-pyridyl)-3-P Lidinolatitium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)pheno Lithium (abbreviation: LiPPP), lithium oxide (LiO x ), cesium carbonate, etc. Alkali metals, alkaline earth metals, or compounds thereof can be used. Furthermore, rare earth metal compounds such as erbium fluoride (ErF3) can be used.

[0112] Furthermore, as shown in Figure 8(B), the light-emitting device has two EL layers (103a, 103b) By providing a charge generation layer 104 in between, a structure is formed in which multiple EL layers are stacked between a pair of electrodes. It can also be constructed as a tandem structure. Note that in this embodiment, Figure 8(A As explained below, the hole injection layer (111), hole transport layer (112), light emission layer (113), electron The transport layer (114) and the electron injection layer (115) are described in Figure 8(B) as having holes in them. Ingress layer (111a, 111b), hole transport layer (112a, 112b), light emission layer (113a, 113b), electron transport layer (114a, 114b), electron injection layer (115a, 115b) Each of them shares the same function and materials.

[0113] <Charge generation layer> Note that the charge generation layer 104 in the light-emitting device shown in Figure 8(B) is the first electrode (anode) 10 When a voltage is applied between electrode 1 and the second electrode (cathode) 102, electrons are released into the EL layer 103a. It has the function of injecting and injecting holes into the EL layer 103b. The charge generation layer 104 is positive Even in a configuration in which electron acceptors are added to a pore transport material, the electron transport material The material may also be configured with an electron donor added. It is also acceptable for the materials to be stacked. Furthermore, the charge generation layer 104 is formed using the materials described above. This makes it possible to suppress the increase in driving voltage when EL layers are stacked.

[0114] In the charge generation layer 104, if an electron acceptor is added to the hole transport material, As the hole transport material, the material shown in this embodiment can be used. As a receptor, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinone Examples include dimethane (abbreviated as F4-TCNQ) and chloranil. Examples of metal oxides belonging to groups 4 through 8 in the table can be listed. Specifically, Vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide Examples include stainless steel, manganese oxide, and rhenium oxide.

[0115] Furthermore, the charge generation layer 104 is configured such that an electron donor is added to the electron transport material. In this case, the materials shown in this embodiment can be used as electron transport materials. As electron donors, alkali metals or alkaline earth metals or rare earth metals or elements Metals belonging to groups 2 and 13 of the periodic table, as well as their oxides and carbonates, can be used. Yes, it is possible. Specifically, lithium (Li), cesium (Cs), magnesium (Mg), and Calcium (Ca), ytterbium (Yb), indium (In), lithium oxide, carbonic acid It is preferable to use cesium, etc. Also, organic compounds such as tetrathianaphthalene. It may be used as an electron donor.

[0116] Note that Figure 8(B) shows a configuration in which two EL layers 103 are stacked, but different EL layers A stacked structure of three or more EL layers may be formed by providing a charge generation layer in between.

[0117] <Circuit board> The light-emitting device shown in this embodiment can be formed on various substrates. The type of board is not limited to a specific one. An example of a substrate is a semiconductor substrate (example). Examples include single crystal substrates or silicon substrates, SOI substrates, glass substrates, quartz substrates, and plastics. Substrates, metal substrates, stainless steel substrates, substrates having stainless steel foil, Tungsten substrate, substrate with tungsten foil, flexible substrate, bonded fill Examples include paper containing fibrous materials, or a base film.

[0118] Examples of glass substrates include barium borosilicate glass and aluminoborosilicate glass. Examples include soda-lime glass or other materials. Also, flexible substrates and laminated films. Examples of base films include polyethylene terephthalate (PET) and polyethylene Plasti Acrylic resin and other synthetic resins, polypropylene, polyester, polyvinyl fluoride, Alternatively, polyvinyl chloride, polyamide, polyimide, aramid resin, epoxy resin, inorganic vapor deposition. Examples include film or paper.

[0119] The light-emitting device shown in this embodiment requires a vacuum process such as vapor deposition, and a speed test. Solution processes such as coating and inkjet methods can be used. In such cases, sputtering, ion plating, ion beam deposition, and molecular beam deposition methods are used. This involves using physical vapor deposition methods such as vacuum deposition (PVD) or chemical vapor deposition (CVD). This is possible, especially the functional layer (hole injection layer (111, 111a) included in the EL layer of a light-emitting device. , 111b), hole transport layer (112, 112a, 112b), light-emitting layer (113, 113a , 113b), electron transport layer (114, 114a, 114b), electron injection layer (115, 11 5a, 115b), and the charge generation layer (104)) are deposited using a vapor deposition method (such as vacuum deposition). Coating methods (dip coat, die coat, bar coat, spin coat, spray) (Coating method, etc.), Printing method (Inkjet method, Screen printing (stencil printing), Offset (flat) Printing methods (plate printing), flexographic (relief printing), gravure printing, microcontact printing, nanoimprint It can be formed by methods such as the lint method.

[0120] The EL layer (103, 103a, 103b) of the light-emitting device shown in this embodiment is composed of Each functional layer (hole injection layer (111, 111a, 111b), hole transport layer (112, 11 2a, 112b), light emitting layer (113, 113a, 113b), electron transport layer (114, 11 4a, 114b), electron injection layer (115, 115a, 115b) and charge generation layer (104) ) is not limited to the materials mentioned above; other materials may also be used to fulfill the function of each layer. If they can be combined, they can be used in combination. One example is polymer compounds (oligopolymers). (Sesame, dendrimer, polymer, etc.), medium-molecular-weight compounds (compounds in the intermediate region between low and high molecular weight) Materials (molecular weight 400 to 4000), inorganic compounds (quantum dot materials, etc.) can be used. It is possible. Furthermore, quantum dot materials include colloidal quantum dot materials and alloy-type quantum dot materials. Materials such as core-shell quantum dot materials and core-type quantum dot materials can be used.

[0121] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments. It is assumed that this is possible.

[0122] (Embodiment 3) This embodiment describes a light-emitting device that is one aspect of the present invention. (See Figure 9(A)) The light-emitting device shown comprises a transistor (FET) 202 on the first substrate 201 and a light-emitting device (203R, 203G, 203B, 203W) are electrically connected to form an active matrix It is a rix-type light-emitting device and has multiple light-emitting devices (203R, 203G, 203B, 20 3W) has a common EL layer 204, and each light emits according to the light emission color of each light-emitting device. The device has a microcavity structure in which the optical distance between the electrodes is adjusted. The light emitted from layer 204 is used to form a color filter (206R) on the second substrate 205. This is a top-emission type light-emitting device that is emitted via 206G and 206B.

[0123] The light-emitting device shown in Figure 9(A) is configured such that the first electrode 207 functions as a reflective electrode. Furthermore, the second electrode 208 is formed to function as a semi-transmissive / semi-reflective electrode. Other embodiments include: Refer to the description and use it as appropriate.

[0124] Furthermore, in Figure 9(A), for example, the light-emitting device 203R is a red light-emitting device, and the light-emitting device Vice 203G is a green light-emitting device, light-emitting device 203B is a blue light-emitting device, light-emitting device When Vice 203W is used as a white light-emitting device, as shown in Figure 9(B), light-emitting device 2 03R is set such that the optical distance between the first electrode 207 and the second electrode 208 is 200R. Adjusted, the light-emitting device 203G has an optical distance between the first electrode 207 and the second electrode 208. The separation is adjusted to 200G, and the light-emitting device 203B connects the first electrode 207 and the second electrode Adjust so that the optical distance between pole 208 and the pole is 200B. Note that as shown in Figure 9(B) In the light-emitting device 203R, a conductive layer 210R is laminated on the first electrode 207, and the light-emitting device By laminating the conductive layer 210G in the vice 203G, optical adjustment can be performed. Cut.

[0125] The second substrate 205 has color filters (206R, 206G, 206B) formed on it. Color filters allow a specific wavelength range of visible light to pass through, and also allow a specific wavelength range to pass through. This is a blocking filter. Therefore, as shown in Figure 9(A), it overlaps with the light-emitting device 203R. By placing a color filter 206R that allows only the red wavelength range to pass through at a certain position, Red light emission can be obtained from the optical device 203R. Also, when combined with the light-emitting device 203G By placing a color filter 206G that allows only the green wavelength range to pass through at a certain position, Green light can be obtained from the optical device 203G. Also, when combined with the light-emitting device 203B By placing a color filter 206B that allows only the blue wavelength range to pass through at a certain position, Blue light can be obtained from the optical device 203B. However, the light-emitting device 203W is White light emission can be obtained without the need for a color filter. A black layer (black matrix) 209 may be provided at the ends of the Ruta. The color filters (206R, 206G, 206B) and the black layer 209 are made of transparent material. It is acceptable for the overcoat layer used to cover the surface.

[0126] Figure 9(A) shows a structure (top emission type) that extracts light from the second substrate 205 side. The light-emitting device is shown, and as shown in Figure 9(C), the first substrate on which the FET202 is formed. It can also be used as a light-emitting device with a structure that extracts light from the 201 side (bottom emission type). In the case of a bottom-emission type light-emitting device, the first electrode 207 is a semi-transmissive / semi-reflective electrode. The first electrode is formed to function as such, and the second electrode 208 is formed to function as a reflective electrode. Furthermore, the first substrate 201 shall be at least a light-transmitting substrate. (206R', 206G', 206B') are light-emitting devices (2 It is sufficient to place it on the first substrate 201 side rather than on 03R, 203G, and 203B.

[0127] Furthermore, in Figure 9(A), the light-emitting devices are a red light-emitting device, a green light-emitting device, and a blue light-emitting device. While the cases of color light-emitting devices and white light-emitting devices have been shown, one aspect of the present invention is light emission The device is not limited to that configuration, and can include yellow light-emitting devices and orange light-emitting devices. It may also have a configuration that includes these light-emitting devices. Materials used in layers (hole injection layers, hole transport layers, electron transport layers, electron injection layers, charge generation layers, etc.) For this, refer to the descriptions of other embodiments and use them as appropriate. In that case, Therefore, it is necessary to select a color filter appropriately depending on the light-emitting color of the light-emitting device.

[0128] By using the above configuration, a light-emitting device equipped with light-emitting devices that emit multiple colors of light can be created. You can obtain a place.

[0129] The configuration shown in this embodiment may be used in appropriate combination with the configurations shown in other embodiments. It shall be possible.

[0130] (Embodiment 4) This embodiment describes a light-emitting device that is one aspect of the present invention.

[0131] By applying the device configuration of a light-emitting device according to one aspect of the present invention, active matrix It is possible to fabricate casing-type light-emitting devices and passive matrix-type light-emitting devices. Active matrix type light-emitting devices combine light-emitting devices and transistors (FETs). It has a combined configuration. Therefore, it is a passive matrix type light-emitting device, an active matrix type. The light-emitting devices of this type are all included in one aspect of the present invention. A light-emitting device described in other embodiments can be applied to this location.

[0132] In this embodiment, an active matrix type light-emitting device will be described using Figure 10. .

[0133] Figure 10(A) is a top view showing the light-emitting device, and Figure 10(B) is the same as Figure 10(A) but with a dashed line. This is a cross-sectional view taken along line A-A'. The active matrix type light-emitting device is a first substrate 3 A pixel section 302, a drive circuit section (source line drive circuit) 303, and a drive circuit are provided on 01. It has a section (gate line drive circuit) (304a, 304b). Pixel section 302 and drive circuit Parts (303, 304a, 304b) are sealed by the sealing material 305 between the first substrate 301 and the It is sealed between the 2 substrates 306.

[0134] Furthermore, routing wiring 307 is provided on the first substrate 301. It is electrically connected to the external input terminal, FPC308. Note that FPC308 is a drive The dynamic circuit section (303, 304a, 304b) receives an external signal (for example, a video signal, a crossover signal). It transmits signals such as the clock signal, start signal, and reset signal, as well as electrical potential. The FPC308 also has Printed circuit boards (PWBs) may be attached. The state in which it is attached is included in the light-emitting device.

[0135] Next, Figure 10(B) shows the cross-sectional structure.

[0136] The pixel section 302 includes an FET (switching FET) 311 and an FET (current control FET). Multiple pixels having 312 and a first electrode 313 electrically connected to the FET 312. It is formed by [this]. The number of FETs in each pixel is not particularly limited and is not necessarily [limited]. It can be established as needed.

[0137] FET309, 310, 311, 312 are not particularly limited, for example, staggered Transistors such as type 1 and reverse staggered transistors can be applied. Also, top-gate and bo A transistor structure such as a Tomgate type may also be acceptable.

[0138] Furthermore, the semiconductors that can be used in these FETs 309, 310, 311, and 312 are The crystallinity is not particularly limited; amorphous semiconductors, crystalline semiconductors (microcrystalline semiconductors, Whether using a polycrystalline semiconductor, a single-crystal semiconductor, or a semiconductor having a crystalline region in part, Good. Furthermore, by using a crystalline semiconductor, the degradation of transistor characteristics can be suppressed. Therefore, it is preferable.

[0139] Furthermore, these semiconductors include, for example, elements of Group 14, compound semiconductors, and oxide semiconductors. Organic semiconductors can be used, such as silicon-based semiconductors and gallium Semiconductors containing arsenic, oxide semiconductors containing indium, and other materials can be applied.

[0140] The drive circuit section 303 includes FET 309 and FET 310. The ET310 is a circuit containing a unipolar (either N-type or P-type) transistor. It may be formed as follows, or as a CMOS circuit including N-type and P-type transistors. It may be formed in this way. Alternatively, it may be configured to have an external drive circuit.

[0141] The end of the first electrode 313 is covered with an insulator 314. Organic compounds such as negative-type photosensitive resins and positive-type photosensitive resins (acrylic resins), and acids Inorganic compounds such as silicon oxide, silicon nitride, and silicon nitride can be used. Preferably, the upper or lower end of the edge 314 has a curved surface with curvature. This allows for better coverage of the film formed on the upper layer of the insulator 314.

[0142] An EL layer 315 and a second electrode 316 are laminated on the first electrode 313. 315 includes a light-emitting layer, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a charge generation layer, etc. To possess.

[0143] Note that the configuration of the light-emitting device 317 shown in this embodiment is the same as the configuration described in other embodiments. or materials can be applied. Although not shown in the diagram here, the second electrode 316 is external It is electrically connected to the input terminal, FPC308.

[0144] Furthermore, although only one light-emitting device 317 is shown in the cross-sectional view in Figure 10(B), In the element 302, multiple light-emitting devices are arranged in a matrix. Each pixel section 302 is selected to contain a light-emitting device capable of producing three types of light (R, G, B). It can be formed to create a light-emitting device capable of full-color display. Also, there are three types (R In addition to light-emitting devices that can produce light of , G, B, for example, white (W), yellow ( A light-emitting device may be formed that can emit light in colors such as Y, magenta (M), and cyan (C). For example, if a light-emitting device that can produce three types of light (R, G, B) is subjected to the aforementioned several types of light... By adding the resulting light-emitting device, effects such as improved color purity and reduced power consumption can be achieved. It can be obtained. Furthermore, full-color display is possible by combining it with a color filter. It can also be used as a functional light-emitting device. Note that the types of color filters include red (R) and green (G). Blue (B), cyan (C), magenta (M), yellow (Y), etc., can be used.

[0145] FETs (309, 310, 311, 312) on the first substrate 301, and light-emitting device 31 7 is the bonding of the second substrate 306 and the first substrate 301 using a sealing material 305. As a result, the space 3 surrounded by the first substrate 301, the second substrate 306, and the sealing material 305 It has the structure provided in 18. Furthermore, the space 318 contains an inert gas (such as nitrogen or argon). ) or organic matter (including sealant 305) may be filled.

[0146] Epoxy resin or glass frit can be used for the sealant 305. It is preferable to use a material that does not permeate moisture or oxygen as much as possible for the 305 material. The second substrate 306 is similar to the one that can be used for the first substrate 301. Therefore, various substrates described in other embodiments can be used as appropriate. In addition to glass substrates and quartz substrates, FRP (Fiber-Reinforced Plastic) is also used as a substrate. d Plastics), PVF (polyvinyl fluoride), polyester or acrylic A plastic substrate made of resin or the like can be used. Glass frit can be used as a sealing material. When using glass, the first substrate 301 and the second substrate 306 are glass from the viewpoint of adhesion. A substrate is preferred.

[0147] As described above, an active matrix type light-emitting device can be obtained.

[0148] Furthermore, when forming an active matrix type light-emitting device on a flexible substrate, The FET and light-emitting device may be formed directly, but the FET and light-emitting device may be formed on a separate substrate having a release layer. After forming the optical device, the FET and light-emitting device are formed by applying heat, force, laser irradiation, etc. The chair may also be fabricated by peeling it off with a release layer and then transferring it onto a flexible substrate. For example, the lamination of inorganic films such as tungsten film and silicon oxide film, or polyimide, etc. A resin film or the like can be used. Furthermore, as a flexible substrate, it can be used to form transistors. In addition to substrates that can be used, paper substrates, cellophane substrates, aramid film substrates, and polyimide film substrates are also available. Film substrate, fabric substrate (natural fibers (silk, cotton, linen), synthetic fibers (nylon, polyurethane, polypropylene) Polyester or regenerated fibers (acetate, cupro, rayon, recycled polyester) Examples include leather substrates or rubber substrates (including, etc.). This allows for superior durability and heat resistance, as well as reduction in weight and thinness.

[0149] Furthermore, the driving of the light-emitting device in an active-matrix type light-emitting device is performed by the light-emitting device The light is emitted in a pulsed manner (for example, using frequencies such as kHz or MHz), and the structure used for display is... It may also be used as a component. The light-emitting device formed using the above organic compound has excellent frequency characteristics. Because it is equipped with this feature, the time required to drive the light-emitting device can be shortened, and power consumption can be reduced. Furthermore, since heat generation is suppressed due to the reduced operating time, the degradation of the light-emitting device is reduced. It is also possible.

[0150] Note that the configuration shown in this embodiment can be used in combination with the configurations shown in other embodiments as appropriate. It is possible.

[0151] (Embodiment 5) In this embodiment, a light-emitting device according to one aspect of the present invention, and a light-emitting device according to one aspect of the present invention This section describes various electronic devices and automobiles that have been completed by applying a light-emitting device with a seat. To clarify, the light-emitting device is mainly suitable for the display unit in the electronic device described in this embodiment. It can be used.

[0152] The electronic device shown in Figures 11(A) to 11(E) consists of a housing 7000, a display unit 7001, and a speaker. - 7003, LED lamp 7004, operation key 7005 (power switch or operation switch) (Including the switch), connection terminal 7006, sensor 7007 (force, displacement, position, velocity, acceleration, angle) Speed, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, electric current, Includes functions for measuring voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation. It may have a microphone (7008), etc.

[0153] Figure 11(A) shows a mobile computer, and in addition to the above, it includes a switch 7009, It may have an infrared port 7010, etc.

[0154] Figure 11(B) shows a portable image playback device (for example, a DVD player) equipped with a recording medium. In addition to the above, it also has a second display unit 7002, a recording medium reading unit 7011, etc. It is possible.

[0155] Figure 11(C) shows a digital camera with television receiving capabilities, and in addition to the above, it also has an antenna. It may have components such as a 7014, a shutter button 7015, an image receiving unit 7016, etc.

[0156] Figure 11(D) shows a portable information terminal. The portable information terminal displays information on three or more sides of the display unit 7001. It has the function of displaying. Here, information 7052, information 7053, and information 7054 are Examples are shown of how they are displayed on different surfaces. For example, a user might have their mobile information stored in the breast pocket of their clothing. Information 705 displayed in a position visible from above the mobile device while the device is stored. 3 can also be checked. The user can display without taking the mobile device out of their pocket. By checking the display, you can decide, for example, whether or not to answer the phone call.

[0157] Figure 11(E) shows a portable information terminal (including a smartphone), and the housing 7000 has a display unit It may have 7001, operation key 7005, etc. Note that the portable information terminal is a speed The device may also be equipped with connection terminals, sensors, etc. Furthermore, the portable information terminal may display text and image information. It can be displayed on multiple surfaces. Here is an example showing three icons 7050 displayed. Furthermore, the information 7051, indicated by the dashed rectangle, is displayed on the other side of the display unit 7001. It can also do this. An example of information 7051 is notifications of incoming messages such as email, SNS, and phone calls. Subject line, sender name, date, time, battery level, and antenna reception of emails and social media messages. There are factors such as the strength of the faith. Alternatively, the location where information 7051 is displayed is icon 7050. You may also display things like this.

[0158] Figure 11(F) shows a large television system (also called a television or television receiver). It may have a housing 7000, a display unit 7001, etc. Also, here, This shows a configuration in which the chassis 7000 is supported by the stand 7018. The unit can be operated using a separate remote control unit 7111, etc. The 7001 may also be equipped with a touch sensor, allowing it to be operated by touching the display unit 7001 with a finger or other object. It is also possible. The remote control operator 7111 outputs information from the remote control operator 7111. It may have a display unit that shows the following. The remote control unit 7111 has operation keys or The touch panel allows you to control the channel and volume, and the display unit 7001 shows The displayed image can be manipulated.

[0159] The electronic devices shown in Figures 11(A) to 11(F) can have various functions. Example For example, a function to display various information (still images, videos, text images, etc.) on the display unit, touch Panel functions, calendar, date or time display functions, various software (Pro A function to control processing by (grams), wireless communication function, and various control using wireless communication function. Features that connect to a computer network, and transmit or receive various types of data using wireless communication. The function of performing communication, reading programs or data recorded on the recording medium and displaying them on the display unit. It can have functions such as displaying information. Furthermore, in electronic devices having multiple display units... This system primarily displays image information on one display unit and primarily displays text information on another display unit. The function of displaying images, or by displaying images that take parallax into account on multiple display units, creates a three-dimensional image. It can have functions such as displaying an image. Furthermore, in electronic equipment having an image receiving unit... It has functions for taking still images, recording videos, and automatically or manually correcting the captured images. Functions to take pictures, functions to save the captured images to a recording medium (external or built into the camera), and It can have functions such as displaying images on the display unit. The electronic devices shown in (F) may have a variety of functions, but are not limited to these. It is possible.

[0160] Figure 11(G) shows a wristwatch-type portable information terminal, which can be used, for example, as a smartwatch. This can be done. This wristwatch-type portable information terminal consists of a housing 7000, a display unit 7001, and an operating unit Buttons 7022, 7023, connector 7024, band 7025, microphone 702 6. It has a sensor 7029, a speaker 7030, etc. The display unit 7001 has a curved display surface. It is curved and can display information along a curved surface. For example, hands-free calls are possible through communication with a wireless headset. Furthermore, the connection terminal 7024 allows for mutual data transmission with other information terminals. It can also be charged. Charging can be done via wireless power transfer.

[0161] The display unit 7001, mounted on the housing 7000 which also serves as the bezel, has a non-rectangular display area. It has. The display unit 7001 displays an icon representing the time, other icons, etc. This is possible. In addition, the display unit 7001 is a touch panel equipped with a touch sensor (input device). It may also be an input / output device.

[0162] Furthermore, the smartwatch shown in Figure 11(G) can have various functions. For example, For example, it has a function to display various information (still images, videos, text images, etc.) on the display unit, and a touch panel. Features include a calendar, a function to display the date or time, and various software (programs). A function that controls processing by RAM, wireless communication function, and various computers using wireless communication function Features include connecting to a network and transmitting or receiving various types of data using wireless communication. Functions that read programs or data recorded on a recording medium and display them on the display unit. It can have functions such as [specific functions].

[0163] Furthermore, the 7000 housing contains a speaker and sensors (force, displacement, position, velocity, acceleration, angular velocity). Degrees, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, electric current, electricity Includes functions for measuring pressure, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation. It may have a microphone, etc.

[0164] Furthermore, one aspect of the present invention, the light-emitting device, is used in each display unit of the electronic device shown in this embodiment. This makes it possible to create electronic devices with a long lifespan.

[0165] Furthermore, as an electronic device to which a light-emitting device is applied, a foldable device as shown in Figures 12(A) to (C) Examples include portable information terminals that can be unfolded. Figure 12(A) shows a portable information terminal in its unfolded state. This shows 9310. Also, Figure 12(B) shows either the unfolded or folded state. Figure 12(C) shows the mobile information terminal 9310 in an intermediate state of transition to the other state. The image shows the folded personal digital assistant (PDA) 9310. The PDA 9310 is folded In its folded state, it offers excellent portability, and in its unfolded state, it provides a seamless, wide display area. Excellent for viewing from a distance.

[0166] The display unit 9311 is supported by three housings 9315 connected by hinges 9313. The display unit 9311 is a touch panel (input / output) equipped with a touch sensor (input device). It may also be a force device. In addition, the display unit 9311 is connected to the two housings via the hinge 9313. By bending the 9315, the mobile information terminal 9310 can be folded from its unfolded state. It can be reversibly deformed into a fixed state. Furthermore, the light-emitting device according to one aspect of the present invention is a display It can be used in part 9311. Furthermore, it enables the realization of long-life electronic devices. Display unit 931 The display area 9312 in 1 is located on the side of the folded portable information terminal 9310. This is the display area. Display area 9312 contains information icons and frequently used apps and programs. It can display shortcuts to Gram, allowing you to check information and launch apps. It can be done smoothly.

[0167] Furthermore, Figures 13(A) and 13(B) show automobiles to which a light-emitting device is applied. The device can be installed as an integral part of the automobile. Specifically, as shown in Figure 13(A) Exterior lights 5101 (including rear of the vehicle), tire wheels 5102, doors 510 It can be applied to part or all of 3. Also, among the automobiles shown in Figure 13(B) Side display unit 5104, steering wheel 5105, shift lever 5106, seat 5107, This can be applied to the inner rearview mirror 5108, windshield 5109, etc. It may also be applied to other parts of glass windows.

[0168] As described above, an electronic device or automobile to which a light-emitting device according to one aspect of the present invention is applied can be obtained. This can be achieved. In that case, long-life electronic devices can be realized. Also, the applicable electricity The sub-devices and automobiles shown in this embodiment are not limited to those described, but can be applied in any field. It is possible.

[0169] The configuration shown in this embodiment may be used in appropriate combination with the configurations shown in other embodiments. It is possible.

[0170] (Embodiment 6) In this embodiment, a light-emitting device, or a light-emitting device that is a part thereof, is an embodiment of the present invention. The configuration of the lighting device manufactured using this method will be explained with reference to Figure 14.

[0171] Figures 14(A) and (B) show examples of cross-sectional views of a lighting device. Note that Figure 14(A) shows the substrate side. This is a bottom-emission type lighting device that extracts light from the encapsulated substrate side, and Figure 14(B) shows the encapsulated substrate side. This is a top-emission type lighting device that extracts light.

[0172] The lighting device 4000 shown in Figure 14(A) has a light-emitting device 4002 on a substrate 4001. Furthermore, the substrate 4003 has irregularities on the outside of the substrate 4001. Light-emitting device 40 02 has a first electrode 4004, an EL layer 4005, and a second electrode 4006.

[0173] The first electrode 4004 is electrically connected to electrode 4007, and the second electrode 4006 is connected to electrode 4 It is electrically connected to 008. It is also an auxiliary wiring that is electrically connected to the first electrode 4004. 4009 may be provided. Furthermore, an insulating layer 4010 is formed on the auxiliary wiring 4009. Yes, they are.

[0174] Furthermore, substrate 4001 and encapsulating substrate 4011 are bonded together with sealing material 4012. A desiccant 4013 is provided between the encapsulating substrate 4011 and the light-emitting device 4002. This is preferable. Note that the substrate 4003 has an uneven surface as shown in Figure 14(A), so the light-emitting device This can improve the efficiency of extracting light generated by the Vice 4002.

[0175] The lighting device 4200 in Figure 14(B) has a light-emitting device 4202 on a substrate 4201. The light-emitting device 4202 comprises a first electrode 4204, an EL layer 4205, and a second electrode 4206. It has the following characteristics.

[0176] The first electrode 4204 is electrically connected to electrode 4207, and the second electrode 4206 is connected to electrode 4 It is electrically connected to 208. Also, auxiliary wiring 4 is electrically connected to the second electrode 4206. 209 may be provided. Also, an insulating layer 4210 may be provided below the auxiliary wiring 4209. stomach.

[0177] The substrate 4201 and the uneven sealing substrate 4211 are bonded together with a sealing material 4212. Furthermore, a barrier film 4213 and a planarization film 4 are placed between the sealing substrate 4211 and the light-emitting device 4202. 214 may be provided. Note that the sealing substrate 4211 has irregularities as shown in Figure 14(B). Therefore, the efficiency of extracting light generated by the light-emitting device 4202 can be improved.

[0178] Furthermore, an example of the application of these lighting devices is ceiling lights used for indoor lighting. Ceiling lights come in various types, such as surface-mounted and recessed. A lighting device is constructed by combining a light-emitting device with a housing or cover.

[0179] Other applications include footlights that illuminate the floor surface to enhance safety underfoot. It is also possible. Footlights are effective for use in places such as bedrooms, stairwells, and hallways. In this case, the size and shape can be changed as appropriate depending on the size and structure of the room. It is also possible to create a stationary lighting device by combining the device and a support base. .

[0180] Furthermore, it can also be applied as a sheet-shaped lighting device (sheet-shaped lighting). Because the lighting fixtures are mounted on the wall, they don't take up much space and can be used for a wide range of applications. Furthermore, it can be easily scaled up to cover a large area. It can also be used on curved walls and enclosures.

[0181] In addition to the above, a light-emitting device according to one aspect of the present invention may be installed in some of the furniture in the room, Applying a light-emitting device, which is part of it, to create a lighting device that also functions as furniture. It is possible.

[0182] As described above, various lighting devices can be obtained by applying light-emitting devices. This is included in one aspect of the present invention.

[0183] Furthermore, the configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments. It is possible. [Examples]

[0184] In this embodiment, multiple light-emitting devices were fabricated using host materials with different T1 levels, and the light-emitting data The T1 level of the host material used in the luminescent layer of the vice, and the excitation energy of the luminescent material (phosphorescent material) This paper presents the results of an investigation into the impact on reliability in relation to energy.

[0185] The configuration of each light-emitting device fabricated in this embodiment is shown in Table 1 below.

[0186] [Table 1]

[0187] Furthermore, the host material and guest material (phosphorescent material) used in each light-emitting device shown in Table 1. The molecular structure is shown below.

[0188] [ka]

[0189] In this example, in order to compare the T1 levels of each host material, the short-wavelength side of the phosphorescence spectrum is used. From the light edge (spectral onset) to T H(edge) They sought it.

[0190] The emission edge of the phosphorescence spectrum is located near the half-value of the shortest wavelength peak on the short-wavelength ridge. Draw a tangent line, and the wavelength at the point where that tangent line intersects the horizontal axis is obtained from this value T H(edge) of It can be determined. For example, in the case of the phosphorescence spectrum shown in Figure 3, the shortest wavelength side PH Draw a tangent line near the half-power of the wavelength (483 nm), and define the emission end as the point where it intersects the horizontal axis (462 nm). Then, from this value, the T of the substance that exhibits the phosphorescence spectrum shown in Figure 3 H(edge) However, 2 The result is 0.684 eV.

[0191] The phosphorescence spectrum in Figure 3 is the phosphorescence spectrum of the material used in the light-emitting layer of the light-emitting device 3 shown in Table 1. This is the spectrum. The light-emitting layer of light-emitting device 3 is the host material, 5-[3-(4,6 -Diphenyl-1,3,5-triazine-2-yl)phenyl]-7,7-dimethyl-5 H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), and ges The phosphorescent material is [2-(4-phenyl-2-pyridinyl-κN)phenyl [ru-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (Abbreviation: [Ir(ppy)2(4dppy)]) is present.

[0192] Therefore, the phosphorescence spectra of mINc(II)PTzn and PCCP were measured, respectively. Figure 4 shows the phosphorescence spectrum of mINc(II)PTzn, and Figure 5 shows the phosphorescence spectrum of PCCP. Each was shown.

[0193] From the phosphorescence spectrum in Figure 4, the emission edge on the short wavelength side of mINc(II)PTzn (spectrum) The onset of this light is 462 nm, which translates to an energy of 2.684 eV. Furthermore, from the results in Figure 5, the emission edge (onset of the spectrum) on the short-wavelength side of PCCP is 456 This corresponds to a value of nm, which translates to an energy of 2.719 eV.

[0194] Therefore, in the light-emitting layer of the light-emitting device 3, mINc(II) corresponds to the first organic compound. ) Of the T1 levels of PTzn and the T1 levels of PCCP, which corresponds to the second organic compound, The lower energy level, the T1 level (the T1 level of mINc(II)PTzn), is 2.684. It is eV, and therefore T in light-emitting device 3 H(edge) The value is determined to be 2.684 eV. It is possible to change the triplet excitation energy in the luminescent layer from the host material to the guest material. Energy transfer to the material (luminescent substance) is PCCP, mINc(I) in the absence of reverse intersystem crossing. I) When PTzn is generated from the one with the lower T1 level, i.e., mINc(II)PTzn Yes, I can.

[0195] Furthermore, the host material used in each light-emitting device shown in Table 1 is the same as for light-emitting device 3. The results of the measurements were obtained from the phosphorescence spectra of the first and second organic compounds. Maru T H(edge) However, the T of the materials shown as host materials included in the light-emitting layer in Table 1 H( edge) This was consistent (i.e., in all host materials, the T1 level was higher than that of PCCP). (It was low). Therefore, in the light-emitting layer of each light-emitting device, the triplet excitation energy was T shown in Table 2 below H(edge) Energy is transferred from a host material to a guest material (luminescent material). It can be said that energy travel occurs.

[0196] [Table 2]

[0197] Next, the guest materials used in the light-emitting layer of each light-emitting device shown in Table 1 ([Ir(ppy)2(4 dppy)])'s T D(edge) T D(edge) is, [Ir(ppy)2 It can be determined from the absorption edge of the absorption spectrum of (4dppy).

[0198] The absorption edge of an absorption spectrum is the edge on the longest wavelength side of the absorption spectrum, where the longest wavelength is reached. Draw a tangent line near the halfway point of the side peak or shoulder peak, and the intersection of that tangent line and the horizontal axis... This is the wavelength of the point, and from this value T D(edge) This can be calculated. For example, as shown in Figure 6. In the case of an absorption spectrum, the half-value of the shoulder peak on the longest wavelength side (around 490 nm) Draw a tangent line in the vicinity, and define the absorption edge as the point where it intersects the horizontal axis (516 nm). Then, from this value... T of guest material ([Ir(ppy)2(4dppy)]) D(edge) However, 2.403 It is calculated as eV.

[0199] Therefore, the T of the host material in each light-emitting device H(edge) and guest material T D(e dge) Energy difference (T H(edge) -T D(edge) The result was calculated. As shown in 3.

[0200] [Table 3]

[0201] Furthermore, the external quantum efficiency of each light-emitting device was measured, and the value of the reference device was used as a reference based on the measurement results. The normalized external quantum efficiency was calculated (see Table 4). As can be seen from Figure 2, The normalized external quantum efficiency is the T of the host material. H(edge) and guest material T D(edge) Energy difference (T H(edge) -T D(edge) Regardless of the value of ), they are roughly the same. The result was obtained that, in the light-emitting device 6, H(edge) -T D(edg e) The value is negative, and the triplet excitation energy is an endothermic energy transfer. This suggests that, however, this level of difference does not affect the luminescence efficiency. Regarding light efficiency, T H(edge) The impact of its position is small. However, regarding reliability... The inventors have found that this has a significant impact.

[0202] Regarding the lifespan of each light-emitting device, here we define it as the time until the brightness decreases to 70% of the initial brightness. The interval (LT70) is measured, and the normalized lifetime is determined from the measurement results based on the value of the reference device. (See Table 4.) The results are shown in Figure 1.

[0203] [Table 4]

[0204] First, regarding the light-emitting device 6, it was found that although efficiency was improved, its lifespan was significantly reduced. In other words, the endothermic energy transfer of triplet excitation energy can be performed with a certain degree of efficiency. However, it can be said that this significantly shortens the lifespan. Even more importantly, the light-emitting device 1 and the light-emitting device This is the behavior of device 2. In these devices, the triplet excitation energy is released exothermally. Energy is moving (that is, T H(edge) -T D(edge) It has turned positive. (This should be the case, but it still shortens the lifespan.) In other words, this region is related to heat energy - This is a mobile region, and generally the energy of the host material is sufficiently high (from an efficiency standpoint). This can be considered a region, but it suggests that it is insufficient from the perspective of lifetime. On the other hand, the luminescence device In chair 4 and light-emitting device 5, the lifespan improved dramatically, becoming better than that of the reference device. In this way, T H(edge) -T D(edge) It is not greater than or equal to 0, but a certain constant One of the key components of this invention is that the lifespan cannot be ensured unless it takes a positive value of a certain degree. Therefore, as a necessary condition, T H(edge) -T D(edge) The value It can be concluded that the voltage is 0.07 eV or higher.

[0205] Meanwhile, T H(edge) -T D(edge) Even if the value is 0.07eV or higher, the reference data The vice, light-emitting device 3, and light-emitting device 7 are connected to light-emitting device 4 and light-emitting device 5. The lifespan is also getting shorter. Regarding this point, T H(edge) -T D(edge) of The effects of the upper bound and / or inverse interterm crossing must be taken into consideration. As will be discussed later... The reference device, light-emitting device 3, and light-emitting device 7 are affected by reverse intersystem crossover. However, the reduction in lifetime is greater than that of the inverse interterm crossing. H(edge) -T D(edge) The upper limit If we consider that it is controlled by, then more preferably, T H(edge) -T D(ed ge) The upper limit is 0.17 eV (reference device, light-emitting device 3, and light-emitting device S7 T H(edge) -T D(edge) These are 0.175eV and 0.281eV, respectively. (V, 0.298eV).

[0206] Next, we will explain the effect of reverse intersystem crossing. The light-emitting devices fabricated in this embodiment are all Excited complexes are formed by multiple host materials (the first organic compound and the second organic compound). The system is configured such that phosphorescence is obtained as a result of energy transfer to the guest (phosphorescent material). In such light-emitting devices, inverse intersystem crossing hardly occurs in the light-emitting layer. Therefore, in principle, 25% of the singlet excitons generated by carrier recombination and 75 Energy transfer occurs from each of the % triplet excitons to the guest (phosphorescent material). The same applies when the first organic compound and the second organic compound do not form an excited complex. This is the main point of this application. However, the S1 level of the host material (where an excited complex is formed) If the excited complex reaches the S1 level, then T H(edge) In a field where the energy difference is within 0.2 eV In the composite, reverse intersystem crossing in the host material becomes dominant, so the host material Energy transfer to the material is predominantly via a pathway from the singlet excited state. One aspect of the present invention In this case, as described above, the energy transfer from the triplet excited state is dominant initially. This situation is undesirable because it produces an effect.

[0207] In other words, the T of the host material H(edge) and guest material T D(edge) Energy Difference (T H(edge) -T D(edge)In addition to the above, the reverse interterm crossing does not occur. Under certain conditions, that is, 75% of the generated triplet excitons are directly transferred to the guest material. It can be said that this is effective when energy is being transferred. Here, the light-emitting device fabricated in this embodiment Of these, the reference device, light-emitting device 3, and light-emitting device 7 yielded the results shown in Figure 1. Therefore, the result was obtained that the normalized lifetime was shorter compared to light-emitting devices 4 and 5. In the host materials of the reference device and light-emitting device 3 and light-emitting device 7, the inverse term The conditions under which crossing occurs are shown below.

[0208] First, the mINc(II)PTzn and PCCP contained in the light-emitting layer of the light-emitting device 3 are mixed. The fluorescence spectrum of the combined materials (or the excited complex, if one is formed) is on the shorter wavelength side. The S1 level derived from the light-emitting end is obtained by mixing mINc(II)PTzn and PCCP. Material S' H(edge) This was the request.

[0209] The emission edge of the fluorescence spectrum is located near the half-value of the shortest wavelength peak on the short-wavelength side of the ridge. Draw a tangent line, and the wavelength at the point where that tangent line intersects the horizontal axis is S'. H(edge) This can be determined. For example, in the case of the fluorescence spectrum shown in Figure 7, the shortest wavelength side P1 is obtained. Draw a tangent line near the half-value of the light source (513nm), and the point where it intersects the horizontal axis (448nm) is the emission edge. Then, from this value, the S' of the substance that exhibits the fluorescence spectrum shown in Figure 7. H(edge) but , which is found to be 2.768 eV. Therefore, ΔE s’t =S' H(edge) -T H(edge ) = 0.084eV is obtained. Similarly, ΔE for the reference device is also calculated. s’t To seek The reference device showed a voltage of 0.171 eV.

[0210] Here, T H(edge) -T D(edge) Reference device with a voltage of 0.07 eV or higher Regarding light-emitting devices 3-5 and light-emitting device 7, T H(edge) -T D(edg e) and ΔE s’t =S' H(edge) -T H(edge) The figures are summarized in Table 5. .

[0211] [Table 5]

[0212] The reference device is T H(edge) -T D(edge) 0.07 eV to 0.27 eV The following conditions are met, but ΔE s’t Since it is less than 0.2eV, inverse interterm crossing occurs. It can be seen that this is a condition. Also, T H(edge) -T D(edge) is 0.07 eV or less The condition of being below 0.17 eV is not met. Light-emitting devices 3 and 7 are T H(edge) -T D(edge) It also satisfies the condition of being between 0.07 eV and 0.27 eV. It has not been done, and ΔE s’t It is also less than 0.2 eV. Therefore, these devices emit It has a shorter lifespan than optical devices 4 and 5.

[0213] On the other hand, light-emitting devices 4 and 5 are T H(edge) -T D(edge) 0.07 eV In addition to satisfying the condition of being 0.27eV or less, ΔE s’t All of them were in the 0.3eV range. Yes, and inverse intersystem crossing is not dominant. As a result, the longest-lived device in this embodiment. Furthermore, in these devices, T H(edge) -T D(edge ) It also satisfies the condition of being between 0.07 eV and 0.17 eV.

[0214] Note that ΔE s’t Regarding this, if it is too large, the excitation energy will be excessively high compared to the guest material. As the size increases, degradation due to singlet excited states is more likely to occur. Therefore, ΔE s’t It is preferable that the voltage is 0.5 eV or less.

[0215] Based on the results of this embodiment, one aspect of the present invention is a light-emitting device that uses the above-mentioned host material T H(edge) and guest material T D(edge) Energy difference (T H(edg e) -T D(edge) The value of ) is 0.07eV or more and 0.27eV or less, preferably 0. In addition to the condition that the S' of the host material is in the range of 0.7 eV to 0.17 eV, H( edge) and host material T H(edge) Energy difference (S' H(edge) -T H(edge) The value of ) is in the range of 0.2eV to 0.5eV, and the emission is long-lasting. It was found that a device could be obtained.

[0216] The above conditions can be expressed by the following equations (1) and (2). However, T H( edge) -T D(edge) If you place more emphasis on the upper limit, then consider equation (1). The condition in equation (3) is more preferable.

[0217]

number

[0218] Regarding the reference device and light-emitting devices 1 to 7 used in this embodiment, Next, the manufacturing method and device characteristics will be explained in Example 2. [Examples]

[0219] In this embodiment, multiple light-emitting devices (light-emitting device 1 to 902) with different stacking structures of the EL layer 902 are used. A light-emitting device 7) was fabricated, and the obtained device characteristics are shown. Furthermore, a comparative light-emitting device... As a component, the light-emitting layer 913 contains 9-[3-(4,6-diphenyl-1,3,5-triazine- 2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: m Multiple comparison light-emitting devices (comparative light-emitting devices) having at least PCCzPTzn-02 Set a1 to a5) to match the light-emitting devices (light-emitting device 1 to light-emitting device 7) respectively The devices were fabricated and compared with each other. Note that the light-emitting devices fabricated in this example (light-emitting devices) The light-emitting devices 1 to 7, and the comparative light-emitting devices a1 to a5, all have a light-emitting layer 91 3. Common luminescent substance (bis[2-(2-pyridinyl-κN)phenyl-κC][2-(4 -phenyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation:[ Ir(ppy)²(4dppy)])) was used.

[0220] The following describes the specific device structure and fabrication method for the light-emitting device mentioned above. The device structure of the light-emitting device described in this embodiment is as shown in Figure 15. Furthermore, the chemical formulas of the materials used in this embodiment are shown below. Note that the abbreviations attached to the chemical formulas are The numbers will be the same as those used in Example 1.

[0221] [ka]

[0222] [ka]

[0223] First, among the light-emitting devices created in this embodiment, light-emitting device 1 and a comparative one were fabricated. The method for fabricating the comparative light-emitting device a1 will be explained. The specific details of each light-emitting device will be described below. The configuration is as shown in Table 6 below.

[0224] [Table 6]

[0225] Fabrication of light-emitting devices <Fabrication of light-emitting device 1 and comparative light-emitting device a1> The light-emitting device shown in this embodiment is formed on a substrate 900 as shown in Figure 15, and On the pole 901, there is a hole injection layer 911, a hole transport layer 912, an emissive layer 913, and an electron transport layer 914. Electron injection layers 915 are sequentially stacked, and a second electrode 903 is stacked on top of the electron injection layers 915. It has a structure.

[0226] First, a first electrode 901 was formed on the substrate 900. The electrode area was 4 mm². 2 (2mm x 2 The thickness was set to mm. A glass substrate was used for the substrate 900. The first electrode 901 was Indium tin oxide (ITSO) containing silicon dioxide is sputtered to 70 nm It was formed by depositing a film with the specified thickness.

[0227] Here, as a pretreatment, the surface of the substrate is washed with water, then fired at 200°C for 1 hour, followed by UV spectroscopy. The zon treatment was performed for 370 seconds. After that, 1 × 10 -4 Vacuum steaming with internal pressure reduced to approximately Pa The substrate is placed in the deposition apparatus and vacuum baked at 170°C for 30 minutes in the heating chamber of the vacuum deposition apparatus. After the process was completed, the circuit board was allowed to cool for about 30 minutes.

[0228] Next, a hole injection layer 911 was formed on the first electrode 901. The hole injection layer 911 was formed using vacuum vapor 1 × 10 inside the attachment device -4 After reducing the pressure to Pa, DBT3P-II and molybdenum oxide are mixed in D The ratio of BT3P-II to molybdenum oxide is set to 2:1 (mass ratio), and the film thickness is set to 50 nm. Each was formed by co-deposition.

[0229] Next, a hole transport layer 912 was formed on the hole injection layer 911. The hole transport layer 912 is a PCB The film was formed by depositing Bi1BP to a thickness of 20 nm.

[0230] Next, a light-emitting layer 913 was formed on the hole transport layer 912.

[0231] In the case of light-emitting device 1, the light-emitting layer 913 is 2-[3'-(dibenzothiophene-4-I [biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPD) Bq-II) and 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PC) In addition to CP, [2-(4-phenyl-2-pyric acid) is used as a guest material (phosphorescent substance). [2-(2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC] Using iridium(III) (abbreviation: [Ir(ppy)2(4dppy)]), the weight ratio is mINc(II)PTzn:PCCP:[Ir(ppy)2(4dppy)]=0.6: Co-deposition was performed with a ratio of 0.4:0.1. The film thickness was set to 40 nm.

[0232] In the case of comparative light-emitting device a1, 9-[3-(4,6-diphenyl-1,3,5-tria [Zin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviated) Name: mPCCzPTzn-02) and PCCP, plus guest materials (phosphorescent materials) As such, [Ir(ppy)2(4dppy)] is used, and the weight ratio is mPCCzPTzn-0 2:PCCP:[Ir(ppy)2(4dppy)]=0.6:0.4:0.1 Co-deposition was performed using sea urchin. The film thickness was set to 40 nm.

[0233] Next, an electron transport layer 914 was formed on the light-emitting layer 913.

[0234] In the case of the light-emitting device 1, the electron transport layer 914 has a film thickness of 2 mDBTBPDBq-II. The layers were formed by sequentially depositing 0 nm and Bphen to achieve a film thickness of 15 nm. In the case of optical device a1, the film thickness of mPCCzPTzn-02 is 20 nm, and the Bphen film is 20 nm thick. The layers were formed by sequentially depositing them to a thickness of 15 nm.

[0235] Next, an electron injection layer 915 was formed on the electron transport layer 914. The electron injection layer 915 is fluorinated It was formed by depositing lithium (LiF) to a film thickness of 1 nm.

[0236] Next, a second electrode 903 was formed on the electron injection layer 915. The second electrode 903 was made of aluminum. A layer of nium was formed by vapor deposition to a thickness of 200 nm. The second electrode 903 functions as the cathode.

[0237] Through the above process, a light-emitting device is formed on the substrate 900, with an EL layer sandwiched between a pair of electrodes. The hole injection layer 911, hole transport layer 912, and light-emitting layer 913 described in the above process were completed. The electron transport layer 914 and the electron injection layer 915 constitute the EL layer in one aspect of the present invention. It is a functional layer. Furthermore, in the deposition process in the above-described manufacturing method, all deposition is carried out by the resistance heating method. They used the law.

[0238] Furthermore, the light-emitting device fabricated as described above is sealed with another substrate (not shown). Furthermore, when sealing using a different substrate (not shown), the glove box should be kept in a nitrogen atmosphere. In this process, another substrate (not shown) coated with a sealant that hardens when exposed to ultraviolet light is placed on substrate 900. The base is fixed on top, and the sealant adheres to the periphery of the light-emitting device formed on the substrate 900. The plates were bonded together. During sealing, 365nm ultraviolet light at 6J / cm² was applied. 2 Irradiate to solidify the sealant. The sealant was stabilized by heating it at 80°C for one hour.

[0239] <<Operating Characteristics of Light-Emitting Devices 1>> The operating characteristics of each fabricated light-emitting device were measured. The measurements were taken at room temperature (maintained at 25°C). The experiment was conducted in a relaxed atmosphere. Furthermore, the operating characteristics of light-emitting device 1 and comparative light-emitting device a1 were also examined. As a result, the current density-luminance characteristics are shown in Figure 16, the voltage-luminance characteristics in Figure 17, and the luminance-current efficiency characteristics. Figure 18 shows the voltage characteristics, and Figure 19 shows the voltage-current characteristics, respectively.

[0240] Also, 1000 cd / m² 2 The main initial characteristics of each light-emitting device in the vicinity are shown in Table 7 below. show.

[0241] [Table 7]

[0242] Additionally, each light-emitting device has a current of 2.5 mA / cm². 2 The emission spectrum when current is passed through at this current density. The details are shown in Figure 20. As shown in Figure 20, the emission spectra of each light-emitting device are all It has a peak around 561 nm and is contained in the light-emitting layer 913, [Ir(ppy)2( It is suggested that this originates from the luminescence of (4dppy).

[0243] Next, reliability tests were conducted on each light-emitting device. The results of the reliability tests are shown in Figure 21. In Figure 21, the vertical axis represents the normalized luminance (%) when the initial luminance is set to 100%, and the horizontal axis represents This indicates the device's operating time (h). The reliability test was a constant current drive test at 2mA. They did that.

[0244] Next, we have a light-emitting device with a different structure from the light-emitting devices described above (light-emitting device 2 and ratio The following describes the light-emitting device a2). Note that these light-emitting devices are also the same as the light-emitting devices described above. It can be manufactured using a similar method. The specific configuration is shown in Table 8 below.

[0245] [Table 8]

[0246] Note that the abbreviation 2mPCCzPDBq-02 in Table 8 stands for 2-{3-[2-(N-phenyl [9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}dibenn Zo[f,h] represents quinoxaline.

[0247] <<Operating Characteristics of Light-Emitting Devices 2>> The operating characteristics of the fabricated light-emitting device 2 and the comparative light-emitting device a2 were measured. The measurements were taken at room temperature. The results are shown in Figures 22 to 25.

[0248] Also, 1000 cd / m² 2 The main initial characteristics of each light-emitting device in the vicinity are shown in Table 9 below. show.

[0249] [Table 9]

[0250] Additionally, each light-emitting device has a current of 2.5 mA / cm². 2 The emission spectrum when current is passed through at this current density. The details are shown in Figure 26. As shown in Figure 26, the emission spectra of each light-emitting device are all It has a peak around 560 nm and is contained in the light-emitting layer 913, [Ir(ppy)2( It is suggested that this originates from the luminescence of (4dppy).

[0251] Next, reliability tests were conducted on each light-emitting device. The results of the reliability tests are shown in Figure 27. In Figure 27, the vertical axis represents the normalized luminance (%) when the initial luminance is set to 100%, and the horizontal axis represents This indicates the device's operating time (h). The reliability test was a constant current drive test at 2mA. They did that.

[0252] Next, we have a light-emitting device with a different structure from the light-emitting devices described above (light-emitting device 3, light-emitting device Vice 4 and comparative light-emitting device a3) are shown. Note that these light-emitting devices are also shown above. It can be fabricated using the same method as the light-emitting device described below. The specific configuration is as follows: This is shown in Table 10.

[0253] [Table 10]

[0254] Note that the abbreviation mINc(II)PTzn in Table 10 refers to 5-[3-(4,6-diphenyl -1,3,5-triazine-2-yl)phenyl]-7,7-dimethyl-5H,7H-yl The abbreviation 8βN-4mDBtPBfpm represents ndeno[2,1-b]carbazole, which is 4 -[3-(dibenzothiophen-4-yl)phenyl]-8-(naphthalene-2-yl) -[1] Represents benzoflo[3,2-d]pyrimidine

[0255] <<Operating Characteristics of Light-Emitting Devices 3>> Regarding the operating characteristics of the fabricated light-emitting device 3, light-emitting device 4, and comparative light-emitting device a3: The measurements were taken at room temperature. The results are shown in Figures 28 to 31.

[0256] Also, 1000 cd / m² 2 Table 11 below shows the main initial characteristics of each light-emitting device in the vicinity. This will be shown.

[0257] [Table 11]

[0258] Additionally, each light-emitting device has a current of 2.5 mA / cm². 2 The emission spectrum when current is passed through at this current density. The details are shown in Figure 32. As shown in Figure 32, the emission spectra of each light-emitting device are all It has a peak around 564 nm and is included in the light-emitting layer 913, [Ir(ppy)2( It is suggested that this originates from the luminescence of (4dppy).

[0259] Next, reliability tests were conducted on each light-emitting device. The results of the reliability tests are shown in Figure 33. In Figure 33, the vertical axis represents the normalized luminance (%) when the initial luminance is set to 100%, and the horizontal axis represents This indicates the device's operating time (h). The reliability test was a constant current drive test at 2mA. They did that.

[0260] Next, we have a light-emitting device with a different structure from the light-emitting devices described above (light-emitting device 5 and ratio The following describes the light-emitting device a4). Note that these light-emitting devices are also the same as the light-emitting devices described above. It can be manufactured using a similar method. The specific configuration is shown in Table 12 below.

[0261] [Table 12]

[0262] Note that the abbreviation 8mDBtBPNfpm in Table 11 refers to 8-[3'-(dibenzothiophene (-4-yl)(1,1'-biphenyl-3-yl)]naphtho[1',2':4,5]floxacin [3,2-d] Represents pyrimidine.

[0263] ≪Operating Characteristics of Light-Emitting Devices 4≫ The operating characteristics of the fabricated light-emitting device 5 and the comparative light-emitting device a4 were measured. The measurements were taken at room temperature. The results are shown in Figures 34 to 37.

[0264] Also, 1000 cd / m² 2 Table 13 below shows the main initial characteristics of each light-emitting device in the vicinity. This will be shown.

[0265] [Table 13]

[0266] Additionally, each light-emitting device has a current of 2.5 mA / cm². 2 The emission spectrum when current is passed through at this current density. The details are shown in Figure 38. As shown in Figure 38, the emission spectra of each light-emitting device are all It has a peak around 559 nm and is contained in the light-emitting layer 913, [Ir(ppy)2( It is suggested that this originates from the luminescence of (4dppy).

[0267] Next, reliability tests were conducted on each light-emitting device. The results of the reliability tests are shown in Figure 39. In Figure 39, the vertical axis represents the normalized luminance (%) when the initial luminance is set to 100%, and the horizontal axis represents This indicates the device's operating time (h). The reliability test was a constant current drive test at 2mA. They did that.

[0268] Next, we have a light-emitting device with a different structure from the light-emitting devices described above (light-emitting device 6, light-emitting device Vice 7 and comparative light-emitting device a5) are shown. Note that these light-emitting devices are also shown above. It can be fabricated using the same method as the light-emitting device described below. The specific configuration is as follows: This is shown in Table 14.

[0269] [Table 14]

[0270] Note that the abbreviation 3,8mDBtP2Bfpr in Table 14 stands for 3,8-bis[3-(dibenzo This represents thiophene-4-yl)phenyl]benzofl[2,3-b]pyrazine, abbreviated as 4 ,8mDBtP2Bfpm is 4,8-bis[3-(dibenzothiophen-4-yl) This represents [enyl]-[1]benzofloflo[3,2-d]pyrimidine.

[0271] <5> Operating Characteristics of Light-Emitting Devices Regarding the operating characteristics of the fabricated light-emitting device 6, light-emitting device 7, and comparative light-emitting device a5: The measurements were taken at room temperature. The results are shown in Figures 40 to 43.

[0272] Also, 1000 cd / m² 2 Table 15 below shows the main initial characteristics of each light-emitting device in the vicinity. This will be shown.

[0273] [Table 15]

[0274] Additionally, each light-emitting device has a current of 2.5 mA / cm². 2 The emission spectrum when current is passed through at this current density. The details are shown in Figure 44. As shown in Figure 44, the emission spectra of each light-emitting device are all It has a peak around 560 nm and is contained in the light-emitting layer 913, [Ir(ppy)2( It is suggested that this originates from the luminescence of (4dppy).

[0275] Next, reliability tests were conducted on each light-emitting device. The results of the reliability tests are shown in Figure 45. In Figure 45, the vertical axis represents the normalized luminance (%) when the initial luminance is set to 100%, and the horizontal axis represents This indicates the device's operating time (h). The reliability test was a constant current drive test at 2mA. They did that. [Examples]

[0276] In this embodiment, the light-emitting device exhibits longer wavelength emission than those shown in Examples 1 and 2. This section describes the fabrication of a light-emitting device using guest materials in the light-emitting layer. The guest material used in the example was bis{4,6-dimethyl-2-[3-(3,5-dimethyl [phenyl)-5-phenyl-2-pyrazinyl-κN]phenyl-κC}(2,6-dimethyl Ru-3,5-heptandionato-κ 2 O,O') Iridium(III) (Abbreviation: [Ir( This is dmdppr-P)2(dibm)]). Also, the light-emitting device described in this embodiment The device structure is as shown in Figure 15, and the manufacturing method is the same as in Example 2.

[0277] The chemical formulas of the materials used in each light-emitting device in this embodiment are shown below. The specific configuration is shown in Table 16 below.

[0278] [ka]

[0279] [Table 16]

[0280] Note that the abbreviation BPAFLP in Table 16 stands for 4-phenyl-4'-(9-phenylfluore). It represents 9-9-yl)triphenylamine. Also, the abbreviation: 9mDBtBPNfpr represents 9 -[(3'-dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2 ':4,5]Flo[2,3-b]pyrazine is represented, and the abbreviation:2mDBTBPDBq-II is , 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f ,h] represents quinoxaline, abbreviated as 8mDBtBPNfpm, which is 8-[3'-(dibenzo Thiofen-4-yl)(1,1'-biphenyl-3-yl)]naphtho[1',2':4 ,5]Flo[3,2-d]pyrimidine, abbreviated as PCBBiF, is N-(1,1'-bife Nyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)pheny These represent fluorene-9H-fluorene-2-amine.

[0281] <<Operating characteristics of light-emitting devices>> Operating characteristics of the fabricated light-emitting device 8, comparative light-emitting device b1, and comparative light-emitting device b2 Sex was measured. The measurements were taken at room temperature. The results are shown in Figures 46 to 49.

[0282] Also, 1000 cd / m² 2 The main initial characteristics of each light-emitting device in the vicinity are shown in Table 17 below. This will be shown.

[0283] [Table 17]

[0284] Additionally, each light-emitting device has a current of 2.5 mA / cm². 2 The emission spectrum when current is passed through at this current density. The details are shown in Figure 50. As shown in Figure 50, the emission spectra of each light-emitting device are all It has a peak around 640 nm and is contained in the light-emitting layer 913, [Ir(dmdppr It is suggested that this originates from the emission of -P)2(dibm)].

[0285] Next, reliability tests were conducted on each light-emitting device. The results of the reliability tests are shown in Figure 51. In Figure 51, the vertical axis represents the normalized luminance (%) when the initial luminance is set to 100%, and the horizontal axis represents This indicates the device's operating time (h). The reliability test was a constant current drive test at 3mA. They did that.

[0286] Based on the above operating characteristics, the normalized external quantum efficiency and normalized lifetime (L) of each light-emitting device can be determined. T70) was calculated. The results are shown in Table 18. Note that when calculating using normalization, the comparative luminescence device The value of chair b1 was used as the basis for calculation.

[0287] [Table 18]

[0288] Furthermore, the PCBBiF contained in the light-emitting layer of each light-emitting device fabricated in this embodiment is shown in Table 18. The T of the material obtained by mixing the indicated host material (or the excited complex if one is formed) H(e dge) and S' H(edge) , guest material([Ir(ppy)2(4dppy)] )'s T D(edge) The results were obtained in the same manner as in Example 1. The results are shown in Table 19. Note that [Ir (dmdppr-P)2(dibm)] T D(edge) The voltage is 1.974 eV.

[0289] [Table 19]

[0290] Light-emitting device 8 is compared to comparative light-emitting devices b1 and b2, as shown in Table 18. The normalized lifetime shown is long. From the results in Table 19, only the light-emitting device 8 is in Embodiment 1. The conditions of both equations (1) and (2) shown, namely, T H(edge) -T D(ed ge) The value of is 0.07eV or greater and 0.27eV or less, and S' H(edge) -T H (edge) To satisfy the requirement that the value is between 0.2eV and 0.5eV, the lifespan is extended. It can be said that... [Examples]

[0291] In this embodiment, similar to the light-emitting device shown in Example 3, a guest material exhibiting long-wavelength emission is used. This section describes the case in which a light-emitting device is fabricated using the light-emitting layer. The guest material was bis[4,6-dimethyl-2-(2-quinolinyl-κN)phenyl-κ C](2,4-pentanedionato-κ) 2 O,O') Iridium(III) (Abbreviation: [Ir (dmpqn)2(acac)]). Also, the light-emitting device described in this embodiment The vise structure is as shown in Figure 15, and the manufacturing method is the same as in Example 2.

[0292] The chemical formulas of the materials used in each light-emitting device in this embodiment are shown below. The specific configuration is shown in Table 20 below.

[0293] [ka]

[0294] [Table 20]

[0295] Note that the abbreviation PCBBi1BP in Table 20 stands for 4,4'-diphenyl-4''-(9-f This represents phenyl-9H-carbazole-3-yl)triphenylamine, abbreviated as 8(βN2 )-4mDBtPBfpm is 8-[(2,2'-binaphthalene)-6-yl]-4-[ 3-(dibenzothiophen-4-yl)phenyl-[1]benzofl[3,2-d]pyri The term represents a methyln, and its abbreviation is 4,8mDBtP2Bfpm, which stands for 4,8-bis[3-(dibenzothi It represents offen-4-yl)phenyl]-[1]benzofloflo[3,2-d]pyrimidine, Abbreviation: 8βN-4mDBtBPBfpm is 4-[3'-(dibenzothiophene-4- [3,]biphenyl-3-yl]-8-(naphthalene-2-yl)-[1]benzofloxacin[3, [2-d] Represents pyrimidine.

[0296] <<Operating characteristics of light-emitting devices>> Operating characteristics of the fabricated light-emitting device 9, the comparative light-emitting device c1, and the comparative light-emitting device c2 Sex was measured. The measurements were taken at room temperature. The results are shown in Figures 52 to 55.

[0297] Also, 1000 cd / m² 2 The main initial characteristics of each light-emitting device in the vicinity are shown in Table 21 below. This will be shown.

[0298] [Table 21]

[0299] Additionally, each light-emitting device has a current of 2.5 mA / cm². 2 The emission spectrum when current is passed through at this current density. The details are shown in Figure 56. As shown in Figure 56, the emission spectra of each light-emitting device are all It has a peak around 626 nm and is contained in the light-emitting layer 913, [Ir(dmpqn) It is suggested that this originates from the emission of 2(acac)).

[0300] Next, reliability tests were conducted on each light-emitting device. The results of the reliability tests are shown in Figure 57. In Figure 57, the vertical axis represents the normalized luminance (%) when the initial luminance is set to 100%, and the horizontal axis represents This indicates the device's operating time (h). The reliability test was a constant current drive test at 3mA. They did that.

[0301] Based on the above operating characteristics, the normalized external quantum efficiency and normalized lifetime (L) of each light-emitting device can be determined. T70) was calculated. The results are shown in Table 22. Note that when calculating using normalization, the comparative luminescence device The value of c1 was used as the reference.

[0302] [Table 22]

[0303] Furthermore, the PCBBiF and Table 22 are included in the light-emitting layer of each light-emitting device fabricated in this embodiment. The T of the material obtained by mixing the indicated host material (or the excited complex if one is formed) H(e dge) and S' H(edge) , guest material([Ir(dmpqn)2(acac) ])'s T D(edge) The results were obtained in the same manner as in Example 1. The results are shown in Table 23. Note that [I T of r(dmpqn)2(acac)] D(edge) The value is 2.039 eV.

[0304] [Table 23]

[0305] Compared to comparative light-emitting devices c1 and c2, light-emitting device 9 is shown in Table 22. The normalized lifetime shown is large. In the light-emitting device 9, S' H(edge) -T H(e dge) Since the value is estimated to be around 0.4 eV, the results in Table 23 indicate that the emission Only device 9 satisfies both conditions of equation (1) and equation (2) shown in Embodiment 1, i.e. , T H(edge) -T D(edge) The value is between 0.07eV and 0.27eV. , and S' H(edge) -T H(edge) The value is between 0.2eV and 0.5eV. It can be said that the lifespan was extended in order to fulfill that requirement.

[0306] (Reference synthesis example 1) The organic compound used in Example 2 is 4-[3-(dibenzothiophen-4-yl)phenyl] -8-(naphthalene-2-yl)-[1]benzoflo[3,2-d]pyrimidine (abbreviation: The synthesis method for 8βN-4mDBtPBfpm) will be explained. The structural formula of tPBfpm is shown below.

[0307] [ka]

[0308] <4-[3-(dibenzothiophen-4-yl)phenyl]-8-(naphthalene-2-yl) (Lu)-[1]benzofloflo[3,2-d]pyrimidine (abbreviation: 8βN-4mDBtPBfp m) synthesis > First, 8-chloro-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]be 1.5g of rhizoflo[3,2-d]pyrimidine and 0.73g of 2-naphthaleneboronic acid, Add 1.5 g of cesium fluoride and 32 mL of mesitylene to a 100 mL three-necked flask. Nitrogen substitution was performed, and 2'-(dicyclohexylphosphinone)acetophenone ethylene ketal 7 0 mg and Tris(dibenzylideneacetone)dipalladium(0) (abbreviation: Pd2(db) a) 3) 89 mg was added and heated at 120°C for 5 hours under a nitrogen stream. The resulting reaction product Water was added and filtered, and the filtrate was washed with water and ethanol in sequence.

[0309] This filtration material was dissolved in toluene and packed in the order of Celite, alumina, and Celite as a filtration aid. The solution was filtered using an agent. The solvent of the resulting solution was concentrated and recrystallized to obtain the target product. A yellow solid was obtained in a yield of 1.5 g with a yield of 64%. The synthesis scheme is shown in the following formula (a-1).

[0310] [ka]

[0311] The resulting pale yellow solid (1.5 g) was purified by sublimation using the train sublimation method. The purification conditions were: pressure 2.0 Pa, argon gas flow rate 10 mL / min, and 2 The solid was heated at 90°C. After sublimation purification, 0.60 g of the target yellow solid was obtained with a recovery rate of 39%. I got it.

[0312] Nuclear magnetic resonance spectroscopy of the obtained yellow solid ( 1 The results of the analysis (using 1H-NMR) are shown below.

[0313] 1 H-NMR.δ(TCE-d2):7.45-7.50(m,4H), 7.57-7. 62(m,2H), 7.72-7.93(m,8H), 8.03(d,1H), 8.10 (s,1H), 8.17(d,2H), 8.60(s,1H), 8.66(d,1H), 8.98 (s, 1H), 9.28 (s, 1H).

[0314] (Reference synthesis example 2) The organic compound used in Example 2, 8-[3'-(dibenzothiophen-4-yl)(1, 1'-Biphenyl-3-yl)Naphtho[1',2':4,5]Flo[3,2-d]Pyri This document describes the synthesis method for 8mDBtBPNfpm. The structure of tBPNfpm is shown below.

[0315] [ka]

[0316] Step 1: Synthesis of ethyl 1-amino-naphtho[2,1-b]furan-2-carboxylate > First, 4.0g of 2-hydroxynaphthalene-1-carbonitride and 6.6g of potassium carbonate. Place the mixture in a flask, purge the flask with nitrogen, and add 30 mL of DMF and 4 ethyl bromoethyl acetate. 0.0g was added and heated at 80°C for 16 hours. The resulting reaction mixture was added to 100mL of ice water. The mixture was rapidly cooled, stirred for 1 hour, and then filtered. The resulting filtrate was washed with water and rehydrated with ethanol and water. Crystallization yielded 4.4 g of the target product (brown solid) in a yield of 72%. Step 1 synthesis Keem is shown in the following equation (b-1).

[0317] [ka]

[0318] <Step 2: Naphtho[1',2':4,5]Flo[3,2-d]Pyrimidine-8(9H )-On composition> Next, the 1-amino-naphtho[2,1-b]furan-2-carb synthesized in step 1 above 4.4g of ethyl phosphate, 1.8g of formamidine acetate, and 25mL of formamide are poured into a floss. Place in a container and heat at 160°C for 8 hours. Add 100 mL of water to the resulting reaction product and filter. By washing the filtration material with water, 3.9 g of the target substance (brown solid) was obtained in a yield of 96%. The synthesis scheme for step 2 is shown in equation (b-2) below.

[0319] [ka]

[0320] <Step 3: 8-Chloro-naphtho[1',2':4,5]fl[3,2-d]pyrimid Synthesis of n> Next, the naphtho[1',2':4,5]fl[3,2-d]pyriol synthesized in step 2 above. Place 3.9 g of midin-8(9H)-one and 15 mL of phosphoryl chloride in a flask and sterilize it. The mixture was heated at 100°C for 6 hours under a plain airflow. The resulting reaction product was added to 100 mL of ice water and rapidly heated. After cooling, 330 mL of 3M sodium hydroxide solution was added and stirred for 1 hour. This was then filtered. The filtered material was washed with ethanol to obtain 1.8 g of the target product (yellow solid) in 42% yield. The synthesis scheme for Step 3 is shown in equation (b-3) below.

[0321] [ka]

[0322] <Step 4: Synthesis of 8mDBtBPNfpm> Next, the 8-chloro-naphtho[1',2':4,5]floxacin synthesized in step 3 above [3, 2-d] Pyrimidine 1.8g, 3-(dibenzothiophen-4-yl)phenylboronic acid 2.9g, 15mL of 2M potassium carbonate aqueous solution, 150mL of toluene, and 15mL L of ethanol was added, and the flask was purged with nitrogen. Tetrakis(trife) was added to this mixture. Add 0.29g of palladium(0) (nylphosphine) and incubate at 95°C for 12 hours under a nitrogen atmosphere. The mixture was heated. The resulting reaction product was filtered, and the resulting filtrate was sequentially washed with water and ethanol. Ta.

[0323] Next, the resulting filtrate was dissolved in toluene, and then layers of Celite, alumina, and Celite were stacked in that order. After purification using a filtration aid, the target substance is recrystallized with toluene, resulting in a pale yellow solid. The body was obtained in a yield of 3.6 g and 95%. The synthesis scheme for Step 4 is given by the following formula (b-4). show.

[0324] [ka]

[0325] The resulting pale yellow solid (3.6 g) was purified by sublimation using the train sublimation method. Purification was performed at a pressure of 2.7 Pa and an argon flow rate of 5 mL / min, and the pale yellow solid was purified at 310°C. The process was carried out by heating. After sublimation purification, 2.7 g of a pale yellow solid was obtained with a recovery rate of 73%.

[0326] Nuclear magnetic resonance spectroscopy of the obtained pale yellow solid ( 1 The results of the analysis (using 1H-NMR) are shown below.

[0327] 1 H-NMR.δ(TCE-d2):7.45-7.52(m,2H), 7.60-7. 71(m,4H), 7.74-7.86(m,6H), 7.92(d,1H), 8.05 (d,1H), 8.12(d,1H), 8.16(s,1H), 8.19-8.22(m ,2H), 8.64(d,1H), 8.96(s,1H), 9.23(d,1H), 9. 32 (s, 1H).

[0328] (Reference synthesis example 3) The organic compound used in Example 3, 9-[(3'-dibenzothiophen-4-yl)biphen [Lu-3-il]naphth[1',2':4,5]fl[2,3-b]pyrazine (abbreviation: 9m The synthesis method for DBtBPNfpr will be explained. Note that the structure of 9mDBtBPNfpr The construction is shown below.

[0329] [ka]

[0330] <Step 1; 6-Chloro-3-(2-methoxynaphthalene-1-yl)pyrazine-2- Amine synthesis > First, 4.37g of 3-bromo-6-chloropyrazine-2-amine and 2-methoxynaphthalene 4.23g of 1-boronic acid, 4.14g of potassium fluoride, 75g of anhydrous tetrahydrofuran The mL was placed in a three-necked flask fitted with a reflux condenser, and the inside was purged with nitrogen. The inside of the flask was then subjected to reduced pressure. After degassing by stirring, Tris(dibenzylideneacetone)dipalladium(0)( Abbreviation: Pd2(dba)3) 0.57g, tri-tert-butylphosphine (Abbreviation: P (tBu)3)4.5 mL was added and the mixture was stirred at 80°C for 54 hours to allow the reaction to proceed.

[0331] After a predetermined time had elapsed, the resulting mixture was filtered by suction, and the filtrate was concentrated. Subsequently, toluene:vinegar was added. Purification was performed by silica gel column chromatography using ethyl acid = 9:1 as the developing solvent. The desired pyrazine derivative was obtained (yellowish-white powder, yield 2.19 g, yield 36%). Step 1 The synthesis scheme is shown in equation (c-1) below.

[0332] [ka]

[0333] <Step 2; 9-Chloronaphtho[1',2':4,5]Flo[2,3-b]pyrazine Synthesis> Next, the 6-chloro-3-(2-methoxynaphthalene-1-yl) py obtained in step 1 above. 2.18 g of radin-2-amine, 63 mL of anhydrous tetrahydrofuran, and 84 mL of glacial acetic acid are mixed together. The solution was placed in a mouthed flask and the inside was purged with nitrogen. After the flask was cooled to -10°C, nitrite te 2.8 mL of rt-butyl was added dropwise, and the mixture was stirred at -10°C for 30 minutes and then at 0°C for 3 hours. After the procedure, 250 mL of water is added to the resulting suspension and filtered by suction to obtain the desired pyrazi A derivative was obtained (yellowish-white powder, yield 1.48 g, yield 77%). Step 2 synthesis ski The term "Mu" is shown below (c-2).

[0334] [ka]

[0335] <Step 3; 9-[(3'-dibenzothiophen-4-yl)biphenyl-3-yl] Naphtho[1',2':4,5]flof[2,3-b]pyrazine (abbreviation: 9mDBtBPNf) pr) synthesis > Furthermore, the 9-chloronaphtho[1',2':4,5]floxacin[2,3- obtained in step 2 above b) Pyrazine 1.48g, 3'-(4-dibenzothiophene)-1,1'-biphenyl- 3.41 g of 3-boronic acid, 8.8 mL of 2 M potassium carbonate aqueous solution, 100 mL of toluene, 10 mL of tanol was placed in a three-necked flask, and the inside was purged with nitrogen. The inside of the flask was stirred under reduced pressure. After degassing by mixing, bis(triphenylphosphine)palladium(II) dichloride Add 0.84g of Pd(PPh3)2Cl2 and stir at 80°C for 18 hours. They responded.

[0336] After a predetermined time had elapsed, the obtained suspension was filtered by suction and washed with water and ethanol. The body is dissolved in toluene and passed through a filtration aid consisting of layers of Celite, alumina, and Celite. After filtering, the target product was obtained by recrystallization in a mixed solvent of toluene and hexane. Pale yellow solid, yield 2.66g, 82% yield.

[0337] The resulting pale yellow solid (2.64 g) was purified by sublimation using the train sublimation method. The purification conditions were: pressure 2.6 Pa, argon gas flow rate 15 mL / min, and 3 The solid was heated at 15°C. After sublimation purification, the target product was obtained as a pale yellow solid in a yield of 2.34 g and 89%. It was obtained in %. The synthesis scheme for Step 3 is shown below (c-3).

[0338] [ka]

[0339] Furthermore, nuclear magnetic resonance spectroscopy of the pale yellow solid obtained in step 3 above ( 1 (H-NMR) The analysis results are shown below.

[0340] 1 H-NMR.δ(CD2Cl2):7.47-7.51(m,2H),7.60-7. 69(m,5H),7.79-7.89(m,6H),8.05(d,1H),8.10 -8.11(m,2H),8.18-8.23(m,3H),8.53(s,1H),9 .16(d,1H), 9.32(s,1H). [Examples]

[0341] In this embodiment, similar to the light-emitting device shown in Example 3, a guest material exhibiting long-wavelength emission is used. This section describes the case in which a light-emitting device is fabricated using the light-emitting layer. The guest material is bis{4,6-dimethyl-2-[5-(4-cyano-2-methylphenicol (L)-3-(3,5-dimethylphenyl)-2-pyradinyl-κN]phenyl-κC}( 2,2,6,6-tetramethyl-3,5-heptanedionato-κ 2 O,O') Iridium (III) (abbreviation: [Ir(dmdppr-mCP)2(dpm)]). Also, this The device structure of the light-emitting device described in the example is shown in Figure 15, and the manufacturing method is as follows: This is the same as in Example 2.

[0342] The chemical formulas of the materials used in each light-emitting device in this embodiment are shown below. The specific configuration is shown in Table 24 below.

[0343] [ka]

[0344] [Table 24]

[0345] Note that the abbreviation PCBBi1BP in Table 24 refers to 4,4'-diphenyl-4''-(9-f This represents phenyl-9H-carbazole-3-yl)triphenylamine, abbreviated as 9mDBt BNfpr is 9-[(3'-dibenzothiophen-4-yl)biphenyl-3-yl] This represents naphtho[1',2':4,5]flof[2,3-b]pyrazine.

[0346] <<Operating characteristics of light-emitting devices>> The operating characteristics of the fabricated light-emitting devices 10 and 11 were measured. The measurements were taken at room temperature. The results are shown in Figures 58 to 61.

[0347] Also, 1000 cd / m² 2 Table 25 below shows the main initial characteristics of each light-emitting device in the vicinity. This will be shown.

[0348] [Table 25]

[0349] Additionally, each light-emitting device has a current of 2.5 mA / cm². 2 The emission spectrum when current is passed through at this current density. The diagram is shown in Figure 62. As shown in Figure 62, the light-emitting devices 10 and 11 emit light The light spectra have peaks around 654 nm and 652 nm, respectively. The emission originates from [Ir(dmdppr-mCP)2(dpm)] contained in the light-emitting layer 913. This suggests that they are doing so. Furthermore, the measurement results of the external quantum efficiency indicate that both are highly efficient luminescence. It is a device.

[0350] Next, reliability tests were conducted on each light-emitting device. The results of the reliability tests are shown in Figure 63. In Figure 63, the vertical axis represents the normalized luminance (%) when the initial luminance is set to 100%, and the horizontal axis represents This indicates the device's operating time (h). Note that the reliability test was conducted at 3mA (75mA / cm²). 2 ) A constant current drive test was conducted.

[0351] Based on the above operating characteristics, the lifespan (LT95) of the light-emitting devices 10 and 11 is determined to be LT95. The durations were 235 hours and 252 hours, respectively. 75 mA / cm² 2 At a certain current density Despite being in operation, it can be said to have an extremely long lifespan.

[0352] Furthermore, PCBBiF and 9mDB are included in the light-emitting layer of each light-emitting device fabricated in this embodiment. The T of the material mixed with tBPNfpr (or the excited complex if one is formed) H(e dge) and S' H(edge) , guest material([Ir(dmdppr-mCP)2( dpm)])'s T D(edge) The results were obtained in the same manner as in Example 1. The results are shown in Table 26. Oh, the T of [Ir(dmdppr-mCP)2(dpm)] D(edge) is 1.953 It is eV.

[0353] [Table 26]

[0354] Both light-emitting devices 10 and 11 have high luminous efficiency and long lifespan. (See Table 26 for details.) From the results, both the light-emitting devices 10 and 11 are based on formula (1) and shown in Embodiment 1. Both conditions of equation (2), namely, T H(edge) -T D(edge) The value is 0.07 eV or greater and 0.27eV or less, and S' H(edge) -T H(edge) The value is 0 Since it satisfies the requirement of being between 0.2eV and 0.5eV, it can be said to have a long lifespan.

[0355] (Reference synthesis example 4) The organometallic complex used in Example 5, bis{4,6-dimethyl-2-[5-(4-cyano-2 [methylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN]phen Nyl-κC}(2,2,6,6-tetramethyl-3,5-heptanedionato-κ) 2 O,O ') Iridium(III) (abbreviation: [Ir(dmdppr-mCP)2(dpm)]) The synthesis method will be explained. Note that the structure of [Ir(dmdppr-mCP)2(dpm)] The construction is shown below.

[0356] [ka]

[0357] <Step 1; 5-(4-cyano-2-methylphenyl)-2,3-bis(3,5-dimethylphenyl) Synthesis of tylphenyl)pyrazine (abbreviation: Hdmdppr-mCP) First, 5,6-bis(3,5-dimethylphenyl)pyrazine-2-yltrifluorometh 1.97g of sulfonic acid, 0.89g of 4-cyano-2-methylphenylboronic acid, phosphoric acid Place 3.48g of tripotassium, 37mL of toluene, and 3.7mL of water into a three-necked flask and... Nitrogen was purged. After degassing by stirring the flask under reduced pressure, Tris(dibenzylide) (Acetone) Dipalladium(0) 0.042g, Tris(2,6-dimethoxyphenyl) 0.082 g of phosphine was added and refluxed for 7 hours. After the predetermined time, extraction with toluene was performed. This was done. Subsequently, silica gel was developed using a hexane:ethyl acetate = 5:1 (volume ratio) solvent. Purified by column chromatography, the target pyrazine derivative Hdmdppr-mCP( (Abbreviated name) was obtained (white solid, yield 1.16 g, yield 65%). The synthesis scheme of Step 1 was As shown in (d-1) below.

[0358] [ka]

[0359] Step 2; di-μ-chlorotetrakis{4,6-dimethyl-2-[5-(4-shya (no-2-methylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN ]phenyl-κC}diiridium(III) (abbreviation: [Ir(dmdppr-mCP)2 Synthesis of Cl]2) Next, 15 mL of 2-ethoxyethanol and 5 mL of water, and the Hdmdpp obtained in step 1 above. r-mCP (abbreviation) 1.16g, Iridium chloride hydrate (IrCl3·H2O) (Furuya) Place 0.42g (manufactured by Kinzokusha) into a round-bottom flask fitted with a reflux tubing, and place the flask in an argon atmosphere. It was replaced. Afterwards, it was irradiated with microwaves (2.45GHz 100W) for 2 hours to induce a reaction. After a predetermined time has elapsed, the obtained residue is filtered by suction with methanol and washed to obtain the dinuclear complex [Ir(d mdppr-mCP)2Cl]2 (abbreviated) was obtained (orange-brown solid, yield 1.12g, yield) 76%). The synthesis scheme for Step 2 is shown below (d-2).

[0360] [ka]

[0361] <Step 3: Synthesis of [Ir(dmdppr-mCP)2(dpm)]> Furthermore, 20 mL of 2-ethoxyethanol and the dinuclear complex obtained in step 2 above [Ir(dm dppr-mCP)2Cl]2 (abbreviation) 1.11g, dipivaloylmethane (abbreviation: Hdp Place 0.29g of m and 0.56g of sodium carbonate into a round-bottom flask fitted with a reflux condenser. The inside of the lasco was purged with argon. Then, microwaves (2.45 GHz, 100 W) were applied for 2 hours. The mixture was irradiated and reacted. The solvent was removed by distillation, and the resulting residue was used as the developing solvent, with dichloromethane being used instead. After purification by silica gel column chromatography, dichloromethane and methanol were used. By recrystallizing in a mixed solvent, the organometallic complex [Ir(dmdppr-mCP)2 (dpm) was obtained as a dark red solid (yield: 0.60 g, yield: 48%).

[0362] The obtained dark red solid (0.60 g) was purified by sublimation using the train sublimation method. The purification conditions were a pressure of 2.6 Pa and an argon gas flow rate of 10.5 mL / min. The solid was heated at 315°C. After sublimation purification, the target product was obtained as a dark red solid in a yield of 0.48 g. 80% was obtained. The synthesis scheme for Step 3 is shown below (d-3).

[0363] [ka]

[0364] Furthermore, nuclear magnetic resonance spectroscopy of the dark red solid obtained in step 3 above ( 1 (H-NMR) The analysis results are shown below. Also, 1 The H-NMR chart is shown in Figure 64. From these results, the upper The organometallic complex represented by the structural formula (101) described above, [Ir(dmdppr-mCP)2(d It was found that pm) was obtained.

[0365] 1 H-NMR.δ(CD2Cl2):0.91(s,18H),1.41(s,6H), 1.94(s,6H),2.37(s,12H),2.45(s,6H),5.62(s ,1H),6.48(s,2H),6.82(s,2H),7.19(s,2H),7. 36(s,4H),7.49(d,2H),7.57(d,2H),7.60(s,2H ), 8.42(s,2H).

[0366] (Reference synthesis example 5) An organometallic complex, bis{4,6-}, which can be used in a light-emitting device according to one aspect of the present invention, is used in a light-emitting device. Dimethyl-2-[5-(3-cyano-2-methylphenyl)-3-(3,5-dimethylphenyl) [phenyl)-2-pyrazinyl-κN]phenyl-κC}(2,2,6,6-tetramethyl- 3,5-Heptanedionato-κ 2 O,O') Iridium(III) (Abbreviation: [Ir(dm The synthesis method for dppr-m3CP)2(dpm)]) will be explained. Note that [Ir(d The structure of mdppr-m3CP)2(dpm) is shown below.

[0367] [ka]

[0368] <Step 1; 5-(3-cyano-2-methylphenyl)-2,3-bis(3,5-dimethylphenyl) Synthesis of tylphenyl)pyrazine (abbreviation: Hdmdppr-m3CP) First, 5,6-bis(3,5-dimethylphenyl)pyrazine-2-yltrifluorometh 2.15g of sulfonic acid, 0.95g of 3-cyano-2-methylphenylboronic acid, phosphoric acid Place 3.76g of tripotassium, 40mL of toluene, and 4.0mL of water into a three-necked flask and... Nitrogen was purged. After degassing by stirring the flask under reduced pressure, Tris(dibenzylide) (Acetone) Dipalladium(0) 0.045g, Tris(2,6-dimethoxyphenyl) 0.087 g of phosphine was added and refluxed for 7.5 hours. After the predetermined time, extraction with toluene was performed. The process was carried out. Subsequently, silica was developed using a hexane:ethyl acetate = 5:1 (volume ratio) mixture as the developing solvent. The target pyrazine derivative Hdmdppr-m3C was purified by gel column chromatography. P (abbreviation) was obtained (white solid, yield 1.57 g, yield 80%). Synthetic ski of Step 1 The term "Mu" is shown below (e-1).

[0369] [ka]

[0370] <Step 2; di-μ-chlorotetrakis{4,6-dimethyl-2-[5-(3-shea (no-2-methylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN ]phenyl-κC}diiridium(III) (abbreviation: [Ir(dmdppr-m3CP) Synthesis of 2Cl[2] Next, 15 mL of 2-ethoxyethanol and 5 mL of water, and the Hdmdpp obtained in step 1 above. r-m3CP (abbreviation) 1.57g, Iridium chloride hydrate (IrCl3·H2O) (full 0.57g (manufactured by Ya Metal Co., Ltd.) is placed in a round-bottom flask fitted with a reflux tubing, and the flask is subjected to argon gas. The material was replaced. Then, microwaves (2.45 GHz, 100 W) were irradiated for 2 hours to induce a reaction. After a predetermined time has elapsed, the obtained residue is filtered by suction with methanol and washed to obtain the dinuclear complex [Ir( [dmdppr-m3CP)2Cl]2 (abbreviated) was obtained (red-orange solid, yield 1.44g). Yield 73%. The synthesis scheme for Step 2 is shown below (e-2).

[0371] [ka]

[0372] Step 3; Bis{4,6-dimethyl-2-[5-(3-cyano-2-methylphenyl )-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN]phenyl-κC}(2 ,2,6,6-tetramethyl-3,5-heptanedionato-κ 2 O,O') Iridium ( III) Synthesis of [Ir(dmdppr-m3CP)2(dpm)] (abbreviation: [Ir(dmdppr-m3CP)2(dpm)]) Furthermore, 20 mL of 2-ethoxyethanol and the dinuclear complex obtained in step 2 above [Ir(dm dppr-m3CP)2Cl]2 (abbreviation) 1.44g, dipivaloylmethane (abbreviation: Hd Place 0.39g of (pm) and 0.74g of sodium carbonate into a round-bottom flask fitted with a reflux condenser. The flask was purged with argon. Then, microwaves (2.45 GHz, 100 W) were applied twice. The mixture was irradiated for a specified time and allowed to react. The solvent was removed by distillation, and the resulting residue was treated with dichloromethane as the developing solvent. After purification by silica gel column chromatography, dichloromethane and methanol were separated. By recrystallizing in a mixed solvent, [Ir(dmdppr-m3CP)2(dpm )] (abbreviation) was obtained as a dark red solid (yield 1.01g, yield 61%). 0.96 g of the solid was purified by sublimation using the train sublimation method. The sublimation purification conditions were as follows: At a pressure of 2.6 Pa, solidify at 305°C while flowing argon gas at a flow rate of 10.5 mL / min. The body was heated. After sublimation purification, the target substance was obtained as a dark red solid in a yield of 0.71 g and 74%. The synthesis scheme for Step 3 is shown below (e-3).

[0373] [ka]

[0374] Furthermore, nuclear magnetic resonance spectroscopy of the dark red solid obtained in step 3 above ( 1 (H-NMR) The analysis results are shown below. Also, 1 The H-NMR chart is shown in Figure 65. From this, In the synthesis example, the organometallic complex represented by the above structural formula (100) [Ir(dmdppr It was found that -m3CP)2(dpm)] was obtained.

[0375] 1 H-NMR.δ(CD2Cl2):0.92(s,18H),1.42(s,6H), 1.95(s,6H),2.37(s,12H),2.59(s,6H),5.64(s ,1H),6.49(s,2H),6.83(s,2H),7.19(s,2H),7. 34-7.40(m,6H),7.58(d,2H),7.70(d,2H),8.39 (s, 2H). [Explanation of Symbols]

[0376] 101 First electrode 102 Second electrode 103 EL layer 103a, 103b EL layer 104 Charge generation layer 111, 111a, 111b Hole injection layer 112, 112a, 112b Hole transport layer 113, 113a, 113b Emitting layer 114, 114a, 114b electron transport layer 115, 115a, 115b electron injection layer 200R, 200G, 200B optical distance 201 First substrate 202 Transistors (FETs) 203R, 203G, 203B, 203W Light-emitting devices 204 EL layer 205 Second substrate 206R, 206G, 206B color filters 206R', 206G', 206B' color filters 207 First electrode 208 Second electrode 209 Black Matrix 210R, 210G conductive layer 301 First substrate 302 pixel section 303 Drive circuit section (source line drive circuit) 304a, 304b Drive circuit section (gate line drive circuit) 305 sealant 306 Second substrate 307 Wiring 308 FPC 309 FET 310 FET 311 FET 312 FET 313 First electrode 314 Insulators 315 EL layer 316 Second electrode 317 Light-emitting devices 318 Space 900 circuit boards 901 First electrode 902 EL layer 903 Second electrode 911 Hole injection layer 912 Hole transport layer 913 Emitting layer 914 Electron transport layer 915 Electron injection layer 4000 Lighting devices 4001 circuit board 4002 Light-emitting devices 4003 circuit board 4004 First electrode 4005 EL layer 4006 Second electrode 4007 Electrode 4008 Electrode 4009 Auxiliary wiring 4010 Insulating layer 4011 Sealing substrate 4012 Sealant 4013 Desiccant 4200 Lighting equipment 4201 circuit board 4202 Light-emitting devices 4204 First electrode 4205 EL layer 4206 Second electrode 4207 Electrode 4208 Electrode 4209 Auxiliary wiring 4210 Insulating layer 4211 Sealing substrate 4212 Sealant 4213 Barrier film 4214 Planarization film 5101 Light 5102 Wheel 5103 Door 5104 Display section 5105 Handle 5106 Shift lever 5107 Seat 5108 Inner Rearview Mirror 5109 Windshield 7000 cabinets 7001 Display section 7002 2nd display section 7003 Speaker 7004 LED Lamp 7005 Operation Keys 7006 Connection terminal 7007 Recovery 7008 Microphone 7009 Switch 7010 Infrared Port 7011 Recording medium reading unit 7014 Antenna 7015 Shutter button 7016 Image receiving unit 7022, 7023 Operation Buttons 7024 Connection terminal 7025 Band 7026 Microphone 7029 Sensor 7030 speaker 7050 Icon Information 7051, 7052, 7053, 7054 7111 Remote Control Unit 9310 Mobile Information Terminal 9311 Display section 9312 Display area 9313 Hinge 9315 enclosure

Claims

1. A light-emitting layer is provided between a pair of electrodes. The light-emitting layer comprises a first organic compound, a second organic compound, and a phosphorescent material. Of the T1 levels of the first organic compound and the T1 levels of the second organic compound, the T1 level with the lower energy level (T Ｈ（ｅｄｇｅ） ) and the T1 level of the phosphorescent material (T Ｄ（ｅｄｇｅ） ) and the energy difference (T Ｈ（ｅｄｇｅ） -T Ｄ（ｅｄｇｅ） ) is between 0.07 eV and 0.27 eV, The S1 level (S') of the material obtained by mixing the first organic compound and the second organic compound Ｈ（ｅｄｇｅ） ) and T Ｈ（ｅｄｇｅ） Energy difference (S') Ｈ（ｅｄｇｅ） -T Ｈ（ｅｄｇｅ） ) is between 0.2 eV and 0.4 eV, The first organic compound has a pyridine ring, a diazine ring or a triazine ring structure, and a light-emitting device (however, T Ｈ（ｅｄｇｅ） refers to the T1 level with lower energy among the T1 levels derived from the emission end on the short wavelength side of the phosphorescence spectra of the first organic compound and the second organic compound. Also, T Ｄ（ｅｄｇｅ） refers to the T1 level derived from the absorption end of the absorption spectrum of the phosphorescent material. Also, S’ Ｈ（ｅｄｇｅ） refers to the S1 level derived from the emission end on the short wavelength side of the fluorescence spectrum of the material obtained by mixing the first organic compound and the second organic compound).

2. A light-emitting layer is provided between a pair of electrodes. The light-emitting layer comprises a first organic compound, a second organic compound, and a phosphorescent material. Of the T1 levels of the first organic compound and the T1 levels of the second organic compound, the T1 level with the lower energy level (T Ｈ（ｅｄｇｅ） ) and the T1 level of the phosphorescent material (T Ｄ（ｅｄｇｅ） ) and the energy difference (T Ｈ（ｅｄｇｅ） -T Ｄ（ｅｄｇｅ） ) is between 0.07 eV and 0.17 eV, The S1 level (S') of the material obtained by mixing the first organic compound and the second organic compound Ｈ（ｅｄｇｅ） ) and T Ｈ（ｅｄｇｅ） Energy difference (S') Ｈ（ｅｄｇｅ） -T Ｈ（ｅｄｇｅ） ) is between 0.2 eV and 0.4 eV, The first organic compound is a light-emitting device having a pyridine ring, diazine ring, or triazine ring structure (however, T Ｈ（ｅｄｇｅ） This refers to the T1 level with the lower energy among the T1 levels derived from the emission edge on the short-wavelength side of the phosphorescence spectra of the first organic compound and the second organic compound. Ｄ（ｅｄｇｅ） This refers to the T1 level derived from the absorption edge of the absorption spectrum of the phosphorescent material. Also, S' Ｈ（ｅｄｇｅ） This refers to the S1 level derived from the emission edge on the short-wavelength side of the fluorescence spectrum of a material obtained by mixing the first organic compound and the second organic compound.

3. In claim 1 or claim 2, The first organic compound and the second organic compound are a combination that forms an excited complex, and the S1 level (S' Ｈ（ｅｄｇｅ） ) is a light-emitting device derived from the emission edge on the short wavelength side of the fluorescence spectrum of the excited complex.

4. In any one of claims 1 to 3, The first organic compound is a π-electron-deficient heteroaromatic compound used in a light-emitting device.

5. In any one of claims 1 to 4, The second organic compound is a carbazole derivative, which is used in the light-emitting device.

6. A light-emitting device according to any one of claims 1 to 5, A light-emitting device having a transistor having an oxide semiconductor.

7. A light-emitting device according to any one of claims 1 to 5, A light-emitting device having a flexible substrate.

8. A light-emitting device according to any one of claims 1 to 5, A light-emitting device having an FPC.

9. A light-emitting device according to any one of claims 6 to 8, An electronic device having at least one of the following: a microphone, a camera, control buttons, an external connection port, or a speaker.

10. A light-emitting device according to any one of claims 1 to 5, A lighting device having at least one housing or cover.

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