Light-emitting device, electronic device, and lighting device

Abstract

To provide a novel light-emitting device that is highly convenient, useful, and reliable.SOLUTION: A light-emitting device includes a second electrode on a first electrode with an EL layer sandwiched therebetween, the EL layer includes an emitting layer and an oxidation-resistant layer on the emitting layer, the EL layer has side surfaces and a blocking layer in contact with the top surface and side surfaces of the EL layer, the second electrode is in contact with the side surfaces of the EL layer via the blocking layer, and the oxidation-resistant layer includes one or more selected from oxides of metals belonging to Groups 4 to 8 of the periodic table and organic compounds having an electron-withdrawing group.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] One embodiment of the present invention relates to a light-emitting device, a light-emitting apparatus, an electronic device, and a lighting apparatus.

[0002] Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one embodiment of the invention disclosed in this specification relates to an object, a method, or a manufacturing method. Alternatively, one embodiment of the present invention relates to a process, a machine, a manufacture, or a composition of matter. Therefore, more specifically, examples of the technical field of one embodiment of the present invention disclosed in this specification include a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, a driving method thereof, or a manufacturing method thereof. [Background technology]

[0003] A method for manufacturing an organic EL display that can form an emissive layer without using a fine metal mask is known. One example of such a method includes the steps of depositing a first luminescent organic material containing a mixture of a host material and a dopant material above an electrode array including first and second pixel electrodes formed above an insulating substrate to form a first luminescent layer as a continuous film extending across a display area including the electrode array, irradiating a portion of the first luminescent layer located above the second pixel electrode with ultraviolet light without irradiating a portion of the first luminescent layer located above the first pixel electrode with ultraviolet light, depositing a second luminescent organic material containing a mixture of a host material and a dopant material different from the first luminescent organic material on the first luminescent layer to form a second luminescent layer as a continuous film extending across the display area, and forming a counter electrode above the second luminescent layer (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-160473 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of one embodiment of the present invention is to provide a novel light-emitting device with excellent convenience, usefulness, or reliability.Another object of one embodiment of the present invention is to provide a novel light-emitting device with excellent convenience, usefulness, or reliability.Another object of one embodiment of the present invention is to provide a novel electronic device with excellent convenience, usefulness, or reliability.Another object of one embodiment of the present invention is to provide a novel lighting device with excellent convenience, usefulness, or reliability.

[0006] Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these will become apparent from the description of the specification, drawings, claims, etc., and it is possible to extract other problems from the description of the specification, drawings, claims, etc. [Means for solving the problem]

[0007] One embodiment of the present invention is a light-emitting device having a second electrode on a first electrode with an EL layer sandwiched therebetween, the EL layer having an emitting layer and an oxidation-resistant layer on the emitting layer, the EL layer having side surfaces and a blocking layer in contact with the top surface and side surfaces of the EL layer, and the second electrode in contact with the side surfaces of the EL layer via the blocking layer, the blocking layer having a hole-transporting material.

[0008] This makes it possible to protect the EL layer. For example, even if the EL layer is exposed to the atmosphere during the manufacturing process of the light-emitting device, the oxidation-resistant layer can suppress oxidation of the EL layer. Furthermore, the blocking layer can protect the side surfaces (or edges) of the EL layer. Furthermore, even in a configuration in which the second electrode is in contact with the side surfaces (or edges) of the EL layer, the presence of the blocking layer can prevent conduction between the first electrode and the second electrode, so that various structures can be applied to the light-emitting device.

[0009] In the light-emitting devices having the above configurations, the oxidation-resistant layer may contain one or more selected from oxides of metals belonging to groups 4 to 8 of the periodic table and organic compounds having electron-withdrawing groups.

[0010] In addition, in the light-emitting devices having the above configurations, the oxidation-resistant layer may contain one or more selected from the group consisting of molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane, 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane, chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane, and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile.

[0011] As a result, when a voltage is applied to the light-emitting device, holes are injected from the oxidation-resistant layer into the second electrode, and electrons are injected into the electron injection / transport layer. Therefore, in a light-emitting device according to one embodiment of the present invention, electrons are not injected from the electrode into the organic-based layer, but rather from one organic-based layer to another. The process of electron injection from the electrode into the organic-based layer may increase the driving voltage of the light-emitting device. However, since this process does not exist in a light-emitting device according to one embodiment of the present invention, the device can have a low driving voltage. Furthermore, since experiments have shown that light-emitting devices with high driving voltages also increase their driving voltage significantly over time, a light-emitting device according to one embodiment of the present invention with a low driving voltage can also have a low increase in driving voltage over time.

[0012] The light-emitting device having the above configuration may further include a blocking layer, the blocking layer having a region sandwiched between the second electrode and the oxidation-resistant layer, the EL layer having a sidewall, and the blocking layer being in contact with the sidewall.

[0013] This allows the edges of the EL layer to be protected. Furthermore, even if the second electrode surrounds the EL layer, electrical continuity between the first electrode and the second electrode can be prevented, allowing various structures to be applied to the light-emitting device. For example, when arranging multiple light-emitting devices, the second electrodes of adjacent light-emitting devices can be connected to each other.

[0014] Another embodiment of the present invention is a light-emitting device including the light-emitting device having any of the above structures and a transistor or a substrate.

[0015] Another embodiment of the present invention is a light-emitting device including a first light-emitting device, a second light-emitting device, and a partition wall. The first light-emitting device has a second electrode over a first electrode with a first EL layer sandwiched therebetween, the first EL layer having a first light-emitting layer and a first oxidation-resistant layer over the first light-emitting layer. The second light-emitting device has a second electrode over a third electrode with the second EL layer sandwiched therebetween, and the second EL layer has a second light-emitting layer and a second oxidation-resistant layer over the second light-emitting layer. The second EL layer has a gap between the second EL layer and the first EL layer, the gap having a region overlapping with the partition wall and the second electrode and a region overlapping with the partition wall, and the gap interrupts electrical conduction between the first EL layer and the second EL layer.

[0016] In high-resolution light-emitting devices (display panels) exceeding 1000 ppi, if electrical conduction is found between multiple EL layers, crosstalk occurs, narrowing the color gamut that can be displayed by the light-emitting device. By providing gaps in high-resolution light-emitting devices, it is possible to provide light-emitting devices that can display vivid colors.

[0017] In the light-emitting device having any of the above configurations, the first oxidation-resistant layer may contain one or more selected from oxides of metals belonging to groups 4 to 8 of the periodic table and organic compounds having an electron-withdrawing group.

[0018] In the light-emitting devices having the above configurations, the first oxidation-resistant layer may contain one or more selected from molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, rhenium oxide, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane, 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane, chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane, and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile.

[0019] In the light-emitting device having each of the above configurations, the first EL layer may have a first side surface, the second EL layer may have a second side surface, a blocking layer may be provided in contact with the top surfaces of the first EL layer and the second EL layer and the side surfaces of the first EL layer and the second EL layer, and the second electrode may be in contact with the side surfaces of the first EL layer and the second EL layer via the blocking layer.

[0020] By forming the blocking layer, it is possible to protect the side surfaces (or edges) of each EL layer and also to prevent a short circuit between the electrode formed on each EL layer and a part of each EL layer.

[0021] Another embodiment of the present invention is an electronic device including a light-emitting device having any of the above structures, a sensor, an operation button, a speaker, or a microphone.

[0022] Another embodiment of the present invention is a lighting device including a light-emitting device having any of the above structures and a housing.

[0023] In the drawings accompanying this specification, components are classified by function and shown as block diagrams that are independent of each other, but in reality, it is difficult to completely separate components by function, and one component may be involved in multiple functions.

[0024] In this specification, the names of the source and drain of a transistor are interchangeable depending on the polarity of the transistor and the level of the potential applied to each terminal. Generally, in an n-channel transistor, the terminal to which a low potential is applied is called the source, and the terminal to which a high potential is applied is called the drain. In addition, in a p-channel transistor, the terminal to which a low potential is applied is called the drain, and the terminal to which a high potential is applied is called the source. In this specification, for convenience, the connection relationship of a transistor may be described assuming that the source and drain are fixed, but in reality, the names of the source and drain are interchangeable depending on the above-mentioned potential relationship.

[0025] In this specification, the source of a transistor refers to a source region that is part of a semiconductor film that functions as an active layer, or a source electrode connected to the semiconductor film. Similarly, the drain of a transistor refers to a drain region that is part of the semiconductor film, or a drain electrode connected to the semiconductor film. Furthermore, the gate refers to a gate electrode.

[0026] In this specification, a state in which transistors are connected in series means, for example, a state in which only one of the source or drain of a first transistor is connected to only one of the source or drain of a second transistor, and a state in which transistors are connected in parallel means a state in which one of the source or drain of a first transistor is connected to one of the source or drain of a second transistor, and the other of the source or drain of the first transistor is connected to the other of the source or drain of the second transistor.

[0027] In this specification, "connection" means an electrical connection, and corresponds to a state in which a current, voltage, or potential can be supplied or transmitted. Therefore, a connected state does not necessarily refer to a direct connection, but also includes a state in which a current, voltage, or potential can be supplied or transmitted via a circuit element such as a wiring, resistor, diode, or transistor.

[0028] In this specification, even when components that appear independent on a circuit diagram are connected to each other, in reality, one conductive film may have the functions of multiple components, for example, when part of a wiring functions as an electrode. In this specification, the term "connection" also includes such cases where one conductive film has the functions of multiple components.

[0029] In this specification, one of a first electrode and a second electrode of a transistor refers to a source electrode, and the other refers to a drain electrode. [Effects of the Invention]

[0030] According to one embodiment of the present invention, a novel light-emitting device with excellent convenience, usefulness, or reliability can be provided. According to one embodiment of the present invention, a novel light-emitting device with excellent convenience, usefulness, or reliability can be provided. According to one embodiment of the present invention, a novel electronic device with excellent convenience, usefulness, or reliability can be provided. According to one embodiment of the present invention, a novel lighting device with excellent convenience, usefulness, or reliability can be provided.

[0031] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these will become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract other effects from the description in the specification, drawings, claims, etc. [Brief explanation of the drawings]

[0032] [Figure 1] 1A and 1B are diagrams illustrating the configuration of a light-emitting device according to an embodiment. [Figure 2] 2A to 2E are diagrams illustrating the configuration of a light-emitting device according to an embodiment. [Figure 3] 3A and 3B are diagrams illustrating the configuration of a light emitting device according to an embodiment. [Figure 4] 4A and 4B are diagrams illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 5] 5A to 5C are diagrams illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 6] 6A to 6C are diagrams illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 7] 7A and 7B are diagrams illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 8] FIG. 8 is a diagram illustrating a light emitting device according to an embodiment. [Figure 9]9A and 9B are diagrams illustrating a light emitting device according to an embodiment. [Figure 10] FIG. 10 is a diagram illustrating a light emitting device according to an embodiment. [Figure 11] 11A to 11C are diagrams illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 12] 12A and 12B are diagrams illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 13] FIG. 13 is a diagram illustrating a light emitting device according to an embodiment. [Figure 14] 14A and 14B are diagrams illustrating a light emitting device according to an embodiment. [Figure 15] 15A and 15B are diagrams illustrating a light emitting device according to an embodiment. [Figure 16] 16A and 16B are diagrams illustrating a light emitting device according to an embodiment. [Figure 17] 17A and 17B are diagrams illustrating a light emitting device according to an embodiment. [Figure 18] 18A to 18E are diagrams illustrating electronic devices according to embodiments. [Figure 19] 19A to 19E are diagrams illustrating electronic devices according to embodiments. [Figure 20] 20A and 20B are diagrams illustrating an electronic device according to an embodiment. [Figure 21] 21A and 21B are diagrams illustrating an electronic device according to an embodiment. [Figure 22] FIG. 22 is a diagram illustrating an electronic device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0033] The embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various changes in form and details can be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the embodiments shown below. In the configuration of the invention described below, the same parts or parts having similar functions will be denoted by the same reference numerals in different drawings, and repeated explanations will be omitted.

[0034] (Embodiment 1) In this embodiment, structures of a light-emitting device and a display panel according to one embodiment of the present invention will be described with reference to FIGS.

[0035] 1A and 1B are cross-sectional views illustrating a light-emitting device 100 according to one embodiment of the present invention.

[0036] 1A and 1B, the light-emitting device 100 includes a first electrode 101, a second electrode 102, and an EL layer 103. The EL layer 103 includes an oxidation-resistant layer 105, a hole injection / transport layer 104, an electron injection / transport layer 108, and an emitting layer 113. The first electrode 101 has a region overlapping with the second electrode 102, and the EL layer 103 has a region sandwiched between the first electrode 101 and the second electrode 102.

[0037] The oxidation-resistant layer 105 is located on the uppermost layer of the EL layer 103. This can protect the EL layer 103. For example, even if the EL layer 103 is exposed to the atmosphere during the manufacturing process of the light-emitting device 100, the oxidation-resistant layer 105 can suppress oxidation of the EL layer 103.

[0038] The oxidation-resistant layer 105 is formed using an oxidation-resistant material. Specifically, in this embodiment, a composite material in which an electron acceptor material is added to a hole-transporting material, which is an organic compound, or a stacked structure of a hole-transporting material and an electron acceptor material, which will be described later, can be used as a material that can be used for the charge generation layer of the EL layer. In addition, a material that will be described later as an organic acceptor material used for the hole injection layer in this embodiment can be used as the electron acceptor material.

[0039] Specifically, it is preferable to use, as the electron acceptor material, an oxide of a metal belonging to Groups 4 to 8 in the periodic table, a quinodimethane derivative, or an organic compound having an electron-withdrawing group (a halogen group or a cyano group), such as a chloranil derivative or a hexaazatriphenylene derivative.

[0040] More specifically, examples of oxides of metals belonging to Groups 4 to 8 of the periodic table include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. The use of a metal oxide as the electron acceptor material can improve the oxidation resistance of the oxidation-resistant layer 105. Among these, molybdenum oxide is more preferable as a material for forming the oxidation-resistant layer 105 because it is stable in the air, has low hygroscopicity, and is easy to handle.

[0041] As organic compounds having an electron-withdrawing group such as quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives, more specifically, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane, chloranil, 2,3,6,7,10, Examples of usable materials include 11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ), and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile. In particular, compounds such as HAT-CN, in which an electron-withdrawing group is bonded to a fused aromatic ring having multiple heteroatoms, are more preferable as materials for forming the oxidation-resistant layer 105 because their film quality is stable against heat.

[0042] By configuring the oxidation-resistant layer 105 as described above, when a voltage is applied to the light-emitting device 100, holes are injected from the oxidation-resistant layer 105 into the second electrode 102, and electrons are injected into the electron injection / transport layer 108. Therefore, in the light-emitting device 100, electrons are not injected from the electrode into the organic-based layer, but rather from one organic-based layer to another organic-based layer. The injection of electrons from the electrode into the organic-based layer may increase the driving voltage of the light-emitting device. However, since the light-emitting device 100 does not undergo this process, the light-emitting device can have a low driving voltage. Furthermore, since experiments have shown that light-emitting devices with high driving voltages also experience a large increase in driving voltage over time, the light-emitting device 100 of one embodiment of the present invention, which has a low driving voltage, can also have a low increase in driving voltage over time.

[0043] As shown in FIG. 1A, when a voltage is applied to the light-emitting device 100, the first electrode 101 functions as an anode and the second electrode 102 functions as a cathode.

[0044] 1B, the light-emitting device 100 may also have a blocking layer 107. The blocking layer 107 has a region sandwiched between the second electrode 102 and the oxidation-resistant layer 105. The blocking layer 107 also has regions in contact with the upper surface (or upper portion) and side surfaces (or end portions) of the EL layer 103. The second electrode 102 also has a region in contact with the side surfaces (or end portions) of the EL layer 103 via the blocking layer 107.

[0045] This makes it possible to protect the side surfaces (or edges) of the EL layer 103. Furthermore, even in a configuration in which the second electrode 102 contacts the side surfaces (or edges) of the EL layer 103 as shown in FIG. 1B, the provision of the blocking layer 107 can prevent conduction between the first electrode 101 and the second electrode 102, and therefore various structures can be applied to the light-emitting device 100. For example, when a plurality of light-emitting devices 100 are arranged side by side, a structure in which the second electrodes 102 of adjacent light-emitting devices 100 are connected to each other can be used.

[0046] A hole-transporting material is preferably used as a material for forming the blocking layer 107. Specific examples of the hole-transporting material will be described later in this embodiment. The blocking layer 107 may function as an EL layer. The blocking layer 107 may also have a function as an EL layer.

[0047] The hole injection / transport layer 104 can be formed from the materials described later in this embodiment as materials for the hole injection layer and the hole transport layer. The hole injection / transport layer 104 may be formed as a single layer or multiple layers. Alternatively, the hole injection layer and the hole transport layer may be formed separately. Alternatively, the hole injection / transport layer 104 may be formed as only one of the hole injection layer and the hole transport layer.

[0048] The materials for the electron injection / transport layer 108 may be the materials for the electron injection layer and the hole transport layer described later in this embodiment. The electron injection / transport layer 108 may be formed as a single layer or multiple layers. The electron injection layer and the electron transport layer may be formed separately. The electron injection / transport layer 108 may be either an electron injection layer or an electron transport layer.

[0049] Note that the structure of the light-emitting device of one embodiment of the present invention is not limited to the structure shown in Fig. 1. The basic structure of the light-emitting device will be described with reference to Fig. 2.

[0050] <Basic structure of light-emitting devices> The basic structure of a light-emitting device will be described. Fig. 2A shows a light-emitting device having an EL layer including a light-emitting layer between a pair of electrodes. Specifically, the device has a structure in which an EL layer 103 is sandwiched between a first electrode 101 and a second electrode 102. The EL layer 103 has an oxidation-resistant layer 105.

[0051] 2B shows a light-emitting device with a stacked structure (tandem structure) having multiple (two in FIG. 2B) EL layers (103a, 103b) between a pair of electrodes, with a charge generation layer 106 between the EL layers. A light-emitting device with a tandem structure can be realized as a light-emitting device that can be driven at a low voltage and consumes low power. The EL layer 103b has an oxidation-resistant layer 105.

[0052] The charge generation layer 106 has the function of injecting electrons into one EL layer (103a or 103b) and injecting holes into the other EL layer (103b or 103a) when a potential difference is generated between the first electrode 101 and the second electrode 102. Therefore, in Fig. 2B, when a voltage is applied to the first electrode 101 so that the potential is higher than that of the second electrode 102, electrons are injected from the charge generation layer 106 into the EL layer 103a and holes are injected into the EL layer 103b.

[0053] From the viewpoint of light extraction efficiency, the charge generation layer 106 preferably has transparency to visible light (specifically, the visible light transmittance of the charge generation layer 106 is 40% or more). The charge generation layer 106 functions even if it has lower conductivity than the first electrode 101 or the second electrode 102.

[0054] FIG. 2C also shows a stacked structure of the EL layer 103 of the light-emitting device according to one embodiment of the present invention. In this case, the first electrode 101 functions as an anode, and the second electrode 102 functions as a cathode. The EL layer 103 has a structure in which a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, an electron transport layer 114, an electron injection layer 115, and an oxidation-resistant layer 105 are sequentially stacked on the first electrode 101. The light-emitting layer 113 may have a structure in which a plurality of light-emitting layers emitting different colors are stacked. For example, a light-emitting layer containing a red light-emitting substance, a light-emitting layer containing a green light-emitting substance, and a light-emitting layer containing a blue light-emitting substance are stacked, or a layer containing a carrier-transporting material is interposed between the light-emitting layers. Alternatively, a light-emitting layer containing a yellow light-emitting substance and a light-emitting layer containing a blue light-emitting substance may be combined. However, the stacked structure of the light-emitting layer 113 is not limited to the above. For example, the light-emitting layer 113 may be configured by stacking multiple light-emitting layers emitting the same light. For example, a first light-emitting layer containing a blue light-emitting material and a second light-emitting layer containing a blue light-emitting material may be stacked, or a layer containing a carrier transport material may be interposed between the layers. A configuration in which multiple light-emitting layers emitting the same light may be stacked may provide higher reliability than a single-layer configuration. Even in a tandem structure such as that shown in FIG. 2B , in which multiple EL layers are included, each EL layer is stacked sequentially from the anode side as described above. Furthermore, when the first electrode 101 is a cathode and the second electrode 102 is an anode, the stacking order of the EL layer 103 is reversed. Specifically, the structure is such that 111 on the first electrode 101, which is the cathode, is an electron injection layer, 112 is an electron transport layer, 113 is a light-emitting layer, 114 is a hole transport layer, and 115 is a hole injection layer.

[0055] The light-emitting layers 113 included in the EL layers (103, 103a, 103b) each contain a light-emitting substance or a combination of multiple substances, and can be configured to emit fluorescent or phosphorescent light of a desired emission color. The light-emitting layer 113 may also have a stacked structure with different emission colors. In this case, different light-emitting substances or other substances may be used for each stacked light-emitting layer. Alternatively, a structure in which different emission colors are emitted from the multiple EL layers (103a, 103b) shown in FIG. 2B may also be used. In this case, different light-emitting substances or other substances may be used for each light-emitting layer.

[0056] Furthermore, in a light-emitting device according to one embodiment of the present invention, for example, the first electrode 101 shown in FIG. 2C may be a reflective electrode, the second electrode 102 may be a semi-transmissive and semi-reflective electrode, and a micro-optical resonator (microcavity) structure may be formed. This allows the light emitted from the light-emitting layer 113 included in the EL layer 103 to resonate between the two electrodes, thereby enhancing the light emitted from the second electrode 102.

[0057] When the first electrode 101 of the light-emitting device is a reflective electrode having a laminated structure of a reflective conductive material and a light-transmitting conductive material (transparent conductive film), optical adjustment can be performed by controlling the film thickness of the transparent conductive film. Specifically, it is preferable to adjust the optical distance (product of film thickness and refractive index) between the first electrode 101 and the second electrode 102 to mλ / 2 (where m is a natural number equal to or greater than 1) for the wavelength λ of light obtained from the light-emitting layer 113.

[0058] Furthermore, in order to amplify the desired light (wavelength: λ) obtained from the light-emitting layer 113, it is preferable to adjust the optical distance from the first electrode 101 to the region (light-emitting region) in the light-emitting layer 113 where the desired light is obtained and the optical distance from the second electrode 102 to the region (light-emitting region) in the light-emitting layer 113 where the desired light is obtained to be (2m'+1)λ / 4 (where m' is a natural number of 1 or more) or close to that. Note that the light-emitting region here refers to the recombination region of holes and electrons in the light-emitting layer 113.

[0059] By performing such optical adjustment, the spectrum of the specific monochromatic light obtained from the light-emitting layer 113 can be narrowed, and light emission with good color purity can be obtained.

[0060] In the above case, the optical distance between the first electrode 101 and the second electrode 102 can be strictly defined as the total thickness from the reflective region of the first electrode 101 to the reflective region of the second electrode 102. However, since it is difficult to precisely determine the reflective region of the first electrode 101 or the second electrode 102, the above-mentioned effect can be sufficiently achieved by assuming any position of the first electrode 101 or the second electrode 102 as the reflective region. Furthermore, the optical distance between the first electrode 101 and the light-emitting layer from which desired light is obtained can be strictly defined as the optical distance between the reflective region of the first electrode 101 and the light-emitting region of the light-emitting layer from which desired light is obtained. However, since it is difficult to precisely determine the reflective region of the first electrode 101 or the light-emitting region of the light-emitting layer from which desired light is obtained, the above-mentioned effect can be sufficiently achieved by assuming any position of the first electrode 101 as the reflective region and any position of the light-emitting layer from which desired light is obtained as the light-emitting region.

[0061] The light-emitting device shown in FIG. 2D is a light-emitting device with a tandem structure and a microcavity structure, which allows light of different wavelengths (monochromatic light) to be extracted from each EL layer (103a, 103b). Therefore, separate coloring (e.g., RGB) to obtain different emitted colors is not required. This makes it easy to achieve high resolution. It can also be combined with a colored layer (color filter). Furthermore, it is possible to increase the luminous intensity of a specific wavelength in the front direction, thereby reducing power consumption. The EL layer 103b has an oxidation-resistant layer 105.

[0062] The light-emitting device shown in FIG. 2E is an example of the tandem-structure light-emitting device shown in FIG. 2B. As shown in the figure, the light-emitting device has a structure in which three EL layers (103a, 103b, 103c) are stacked with charge-generating layers (106a, 106b) sandwiched between them. Each of the three EL layers (103a, 103b, 103c) has a light-emitting layer (113a, 113b, 113c), and the light-emitting colors of the light-emitting layers can be freely combined. For example, the light-emitting layer 113a can be blue, the light-emitting layer 113b can be red, green, or yellow, and the light-emitting layer 113c can be blue. Alternatively, the light-emitting layer 113a can be red, the light-emitting layer 113b can be blue, green, or yellow, and the light-emitting layer 113c can be red. The EL layer 103c has an oxidation-resistant layer 105.

[0063] In the light-emitting device according to one embodiment of the present invention, at least one of the first electrode 101 and the second electrode 102 is a light-transmitting electrode (such as a transparent electrode or a semi-transmitting / semi-reflective electrode). When the light-transmitting electrode is a transparent electrode, the visible light transmittance of the transparent electrode is 40% or more. In addition, when the semi-transmitting / semi-reflective electrode is used, the visible light reflectance of the semi-transmitting / semi-reflective electrode is 20% or more and 80% or less, preferably 40% or more and 70% or less. Furthermore, these electrodes have a resistivity of 1×10 -2 It is preferable to set it to Ωcm or less.

[0064] In the above-described light-emitting device according to one embodiment of the present invention, when one of the first electrode 101 and the second electrode 102 is a reflective electrode (a reflective electrode), the reflectivity of the reflective electrode for visible light is set to 40% to 100%, preferably 70% to 100%. -2 It is preferable to set it to Ωcm or less.

[0065] <Specific structure of the light-emitting device> Next, a specific structure of a light-emitting device according to one embodiment of the present invention will be described with reference to FIG. 2. Here, a description will be given using FIG. 2D, which has a tandem structure. The light-emitting devices shown in FIGS. 2A and 2C, which do not have a tandem structure, also have the same EL layer structure. When the light-emitting device shown in FIG. 2D has a microcavity structure, the first electrode 101 is formed as a reflective electrode, and the second electrode 102 is formed as a semi-transmissive and semi-reflective electrode. Therefore, the electrode materials can be used singly or in combination to form a single layer or a stack of layers. The second electrode 102 is formed by selecting a material in the same manner as described above after the EL layer 103b is formed.

[0066] <First Electrode and Second Electrode> The materials forming the first electrode 101 and the second electrode 102 can be any combination of the following materials, as long as they fulfill the functions of both electrodes described above. For example, metals, alloys, electrically conductive compounds, and mixtures thereof can be used. Specific examples include In-Sn oxide (also known as ITO), In-Si-Sn oxide (also known as ITSO), In-Zn oxide, and In-W-Zn oxide. Other metals that can be used include aluminum (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 (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), and neodymium (Nd), as well as alloys containing any combination of these metals. Other examples that can be used include elements belonging to Group 1 or 2 of the periodic table (e.g., lithium (Li), cesium (Cs), calcium (Ca), and strontium (Sr)), rare earth metals such as europium (Eu) and ytterbium (Yb), and alloys containing appropriate combinations of these elements, as well as graphene.

[0067] 2D, when the first electrode 101 is an anode, the hole injection layer 111a and the hole transport layer 112a of the EL layer 103a are sequentially formed by vacuum deposition on the first electrode 101. After the EL layer 103a and the charge generation layer 106 are formed, the hole injection layer 111b and the hole transport layer 112b of the EL layer 103b are similarly sequentially formed on the charge generation layer 106.

[0068] <Hole injection layer> The hole injection layer (111, 111a, 111b) is a layer that injects holes from the first electrode 101, which is an anode, or the charge generation layer (106, 106a, 106b) to the EL layer (103, 103a, 103b), and is a layer that contains either an organic acceptor material or a material with high hole injection properties, or both.

[0069] An organic acceptor material is a material that can generate holes in an organic compound by causing charge separation between the organic acceptor material and another organic compound whose LUMO level and HOMO level are close to each other. Therefore, compounds having an electron-withdrawing group (e.g., a halogen group or a cyano group), such as quinodimethane derivatives, chloranil derivatives, or hexaazatriphenylene derivatives, can be used as the organic acceptor material. For example, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane, chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile, and the like can be used. Among organic acceptor materials, compounds such as HAT-CN, in which an electron-withdrawing group is bonded to a fused aromatic ring containing multiple heteroatoms, are particularly suitable because of their high acceptor properties and thermally stable film quality. Radialene derivatives with electron-withdrawing groups (especially halogen groups such as fluoro groups or cyano groups) are also preferred because of their extremely high electron-accepting properties. Specific examples include α,α',α''-1,2,3-cyclopropanetriylidenetris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropanetriylidenetris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], and α,α',α''-1,2,3-cyclopropanetriylidenetris[2,3,4,5,6-pentafluorobenzeneacetonitrile].

[0070] Furthermore, as a material with high hole injection properties, oxides of metals belonging to Groups 4 to 8 of the periodic table (e.g., transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide) can be used. Specific examples include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is preferred because it is stable in the air, has low hygroscopicity, and is easy to handle. Other examples include phthalocyanine-based compounds such as phthalocyanine (abbreviated as HPc) and copper phthalocyanine (abbreviated as CuPc).

[0071] In addition to the above materials, we also have low molecular weight compounds such as 4,4',4''-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: MTDATA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD), and 1,3,5- Aromatic amine compounds such as tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), 3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), and 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1) can be used.

[0072] In addition, polymeric compounds (oligomers, dendrimers, polymers, etc.) such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD) can be used. Alternatively, polymeric compounds containing added acids, such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (abbreviation: PEDOT / PSS) and polyaniline / poly(styrenesulfonic acid) (PAni / PSS), can also be used.

[0073] Furthermore, a composite material containing a hole transport material and the above-mentioned organic acceptor material (electron accepting material) can also be used as a material with high hole injection properties. In this case, electrons are extracted from the hole transport material by the organic acceptor material, generating holes in the hole injection layer 111, and the holes are injected into the light-emitting layer 113 via the hole transport layer 112. Note that the hole injection layer 111 may be formed as a single layer made of a composite material containing a hole transport material and an organic acceptor material (electron accepting material), or may be formed by laminating the hole transport material and the organic acceptor material (electron accepting material) as separate layers.

[0074] As for hole transporting materials, the hole mobility at a square root of the electric field strength [V / cm] of 600 is 1×10 -6 cm 2 A substance having a hole mobility of 1 / Vs or more is preferred. Note that other substances can be used as long as they have a higher hole transporting property than an electron transporting property.

[0075] As the hole transporting material, a material with high hole transporting properties such as a π-electron rich heteroaromatic compound (for example, a carbazole derivative, a furan derivative, or a thiophene derivative) or an aromatic amine (a compound having an aromatic amine skeleton) is preferred.

[0076] Examples of the carbazole derivatives (compounds having a carbazole skeleton) include bicarbazole derivatives (for example, 3,3'-bicarbazole derivatives), aromatic amines having a carbazolyl group, and the like.

[0077] Specific examples of the bicarbazole derivatives (e.g., 3,3′-bicarbazole derivatives) include 3,3′-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 9,9′-bis(biphenyl-4-yl)-3,3′-bi-9H-carbazole (abbreviation: BisBPCz), bis-{9-(1,1′-biphenyl-3-yl)-9H,9′H-3,3′-bicarbazole} (abbreviation: BismBPCz), 9-(1,1′-biphenyl-3-yl)-9′-(1,1′-biphenyl-4-yl)-9H,9′H-3,3′-bicarbazole (abbreviation: mBPCCBP), and 9-(2-naphthyl)-9′-phenyl-9H,9′H-3,3′-bicarbazole (abbreviation: βNCCP).

[0078] Specific examples of the aromatic amine having a carbazolyl group include 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazol-3-amine (abbreviation: PCBiF), N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)]- 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-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), N,N'-bis(9-phenylcarbazol-3-yl)-N,N'-diphenylbenzene-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-phenyldiphenyl-(9-phenyl-9H-carbazol-3-yl)amine (abbreviation: PCA1BP), N,N'-bis(9-phenylcarbazol-3-yl)-N,N'-diphenylbenzene-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-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF), 3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1), 3-[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA1), 3,6-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA2), 3,6-bis[N-(4-diphenylaminophenyl)-N-(1 -naphthyl)amino]-9-phenylcarbazole (abbreviation: PCzTPN2), 2-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: PCASF), N-[4-(9H-carbazol-9-yl)phenyl]-N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), N,N'-bis[4-(carbazol-9-yl)phenyl]-N,N'-diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviation: YGA2F), 4,4',4''-tris(carbazol-9-yl)triphenylamine (abbreviation: TCTA), etc.

[0079] In addition to the above, examples of the carbazole derivatives include 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)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), and 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA).

[0080] Specific examples of the furan derivatives (compounds having a furan skeleton) include 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II).

[0081] Specific examples of the thiophene derivatives (compounds having a thiophene skeleton) include compounds having a thiophene skeleton, such as 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV).

[0082] Specific examples of the aromatic amine include 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'-bifluoren-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 (abbreviation: BPAFLP), and 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP). '-(9-Phenylfluoren-9-yl)triphenylamine (abbreviation: 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-fluoren-7-yl}phenylamine (abbreviation: DFLADFL), N-(9,9-dimethyl-2-diphenylamino-9H-fluoren-7-yl)diphenylamine (abbreviation: DPNF), 2-[N-(4-diphenylaminophenyl)-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: TDATA), 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino]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), DNTPD, 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4''-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8) ), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine amine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl)naphthalene 4,4'-Diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAPβNB-03), 4,4'-Diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-Diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-Diphenyl-4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-Diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4' '-Phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazol-9-yl)phenyl]tris(1, 1'-biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazol-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi(9H-fluorene)-2-amine (abbreviation: PCBNBSF), N,N-bis([1,1'-biphenyl-4-yl]amine) N-(1,1'-biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi(9H-fluorene)-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), N,N-bis(9,9-dimethyl-9H-fluorene-2- N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine, and the like are mentioned.

[0083] Other examples of hole-transporting materials that can be used include polymeric compounds (oligomers, dendrimers, polymers, etc.) such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD). Alternatively, polymeric compounds containing added acids, such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (abbreviation: PEDOT / PSS) and polyaniline / poly(styrenesulfonic acid) (PAni / PSS), can also be used.

[0084] However, the hole transporting material is not limited to the above, and one or more of various known materials may be used as the hole transporting material.

[0085] The hole injection layers (111, 111a, 111b) can be formed using various known film formation methods, for example, vacuum deposition.

[0086] <Hole transport layer> The hole transport layers (112, 112a, 112b) are layers that transport holes injected from the first electrode 101 by the hole injection layers (111, 111a, 111b) to the light-emitting layers (113, 113a, 113b). The hole transport layers (112, 112a, 112b) are layers that contain a hole transport material. Therefore, the hole transport layers (112, 112a, 112b) can use the same hole transport material that can be used for the hole injection layers (111, 111a, 111b).

[0087] In the light-emitting device of one embodiment of the present invention, the light-emitting layers (113, 113a, 113b) can be formed using the same organic compound as that used in the hole-transport layers (112, 112a, 112b). It is more preferable to use the same organic compound in the hole-transport layers (112, 112a, 112b) and the light-emitting layers (113, 113a, 113b) because holes can be efficiently transported from the hole-transport layers (112, 112a, 112b) to the light-emitting layers (113, 113a, 113b).

[0088] <Light-emitting layer> The light-emitting layers (113, 113a, 113b, 113c) are layers containing light-emitting substances. Light-emitting substances that can be used for the light-emitting layers (113, 113a, 113b, 113c) include substances that emit light of colors such as blue, purple, blue-purple, green, yellow-green, yellow, orange, and red. When multiple light-emitting layers are provided, different light-emitting substances can be used for each light-emitting layer to produce different light-emitting colors (for example, white light emission obtained by combining complementary light-emitting colors). Furthermore, a stacked structure in which each light-emitting layer contains different light-emitting substances may be used.

[0089] Furthermore, the light-emitting layers (113, 113a, 113b, 113c) may contain one or more organic compounds (host materials, etc.) in addition to the light-emitting substance (guest material).

[0090] When multiple host materials are used in the light-emitting layer (113, 113a, 113b, 113c), it is preferable to use a substance having a larger energy gap as the second host material than the energy gaps of the existing guest material and the first host material. Furthermore, it is preferable that the lowest singlet excitation energy level (S1 level) of the second host material is higher than the S1 level of the first host material, and the lowest triplet excitation energy level (T1 level) of the second host material is higher than the T1 level of the guest material. Furthermore, it is preferable that the lowest triplet excitation energy level (T1 level) of the second host material is higher than the T1 level of the first host material. This structure allows the formation of an exciplex using two types of host materials. To efficiently form an exciplex, it is particularly preferable to combine a compound that easily accepts holes (hole-transporting material) with a compound that easily accepts electrons (electron-transporting material). This structure also allows the simultaneous realization of high efficiency, low voltage, and long life.

[0091] The organic compounds used as the host materials (including the first host material and the second host material) may be hole-transporting materials usable in the hole-transporting layers (112, 112a, and 112b) described above or electron-transporting materials usable in the electron-transporting layers (114, 114a, and 114b) described below, as long as they satisfy the requirements for a host material used in an emitting layer. These organic compounds may also be exciplexes composed of multiple organic compounds (the first host material and the second host material described above). An exciplex (also referred to as an exciplex) formed by multiple organic compounds in an excited state has an extremely small difference between the S1 and T1 levels and functions as a TADF material capable of converting triplet excitation energy into singlet excitation energy. A combination of multiple organic compounds that form an exciplex is preferably one in which one of the compounds has a π-electron-deficient heteroaromatic ring and the other has a π-electron-rich heteroaromatic ring. As a combination for forming an exciplex, one of the compounds may be a phosphorescent material such as an iridium, rhodium, or platinum-based organometallic complex or a metal complex.

[0092] There are no particular limitations on the light-emitting substance that can be used in the light-emitting layer (113, 113a, 113b, 113c), and light-emitting substances that convert singlet excitation energy into light emission in the visible light range, or light-emitting substances that convert triplet excitation energy into light emission in the visible light range, can be used.

[0093] <Light-emitting material that converts singlet excitation energy into light> Examples of light-emitting materials that convert singlet excitation energy into light emission and that can be used in the light-emitting layer 113 include the following fluorescent materials (fluorescent materials): pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives. Pyrene derivatives are particularly preferred because of their high light emission quantum yield. Specific examples of pyrene derivatives include N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), (N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)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-amine] (abbreviation: 1,6BnfAPrn-02), N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), and the like.

[0094] In addition, 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)phenyl N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), 4-(10-phenyl-9-anthryl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), 4-(10-phenyl-9-anthryl)-4'- (9-Phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), 4-[4-(10-phenyl-9-anthryl)phenyl]-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPBA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenyl) N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), and the like can be used.

[0095] In addition, N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(1,1'-biphenyl- 2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), Coumarin 545T, N,N'-diphenylquinacridone, (abbreviation: DPQd), rubrene, 5,12-bis(1,1'-biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-yl N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhTD), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2), N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p -mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB),6-Bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), 1,6BnfAP rn-03, 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviated as 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviated as 3,10FrA2Nbf(IV)-02), etc. In particular, pyrene diamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 can be used.

[0096] <Light-emitting material that converts triplet excitation energy into light> Next, examples of luminescent materials that can be used in the luminescent layer 113 and convert triplet excitation energy into luminescence include phosphorescent materials and thermally activated delayed fluorescence (TADF) materials that exhibit thermally activated delayed fluorescence.

[0097] A phosphorescent material is a compound that exhibits phosphorescence but does not exhibit fluorescence at a temperature range from low temperatures (e.g., 77 K) to room temperature (i.e., 77 K to 313 K). The phosphorescent material preferably contains a metal element with a large spin-orbit interaction, such as an organometallic complex, a metal complex (platinum complex), or a rare-earth metal complex. Specifically, a transition metal element is preferred, and a platinum group element (ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), or platinum (Pt)) is particularly preferred. Among these, iridium is preferred because it can increase the transition probability associated with the direct transition between the singlet ground state and the triplet excited state.

[0098] <Phosphorescent material (450nm to 570nm: blue or green)> Examples of phosphorescent materials that exhibit blue or green light and have an emission spectrum with a peak wavelength of 450 nm or more and 570 nm or less include the following materials.

[0099] For example, tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]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-4H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPrptz-3b)3]), tris[3-(5-biphenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPr5btz)3]), and other organometallic complexes with a 4H-triazole skeleton, such as tris[3-methyl-1-(2 organometallic complexes with a 1H-triazole skeleton, such as fac-tris[1-(2,6-diisopropylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz1-mp)3]), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me)3]); organometallic complexes with an imidazole skeleton, such as tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(iPrpmi)3]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me)3]), and bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ]iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ]iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C 2’}iridium(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’] Organometallic complexes with phenylpyridine derivatives having electron-withdrawing groups as ligands, such as iridium(III) acetylacetonate (abbreviation: FIr(acac)), are also included.

[0100] <Phosphorescent material (495nm to 590nm: green or yellow)> Examples of phosphorescent materials that exhibit green or yellow color and have an emission spectrum with a peak wavelength of 495 nm or more and 590 nm or less include the following materials.

[0101] For example, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)3]), tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)2(acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)2(acac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(tBuppm)2(acac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm)2(acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm) 2(acac)]), (acetylacetonato)bis{4,6-dimethyl-2-[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN3]phenyl-κC}iridium(III) (abbreviation: [Ir(dmppm-dmp)2(acac)]), and (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)]). iridium complexes, organometallic iridium complexes with a pyrazine skeleton such as (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac)]) and (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]), tris(2-phenylpyridinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinato-N,C 2’) Iridium(III) acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [Ir(bzq)2(acac)]), tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq)3]), tris(2-phenylquinolinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinolinato-N,C 2’ Organometallic iridium complexes with pyridine skeletons such as iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(acac)]), bis[2-(2-pyridinyl-κN)phenyl-κC][2-(5-phenyl-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], and bis(2,4-diphenyl-1,3-oxazolato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(dpo)2(acac)]), bis{2-[4'-(perfluorophenyl)phenyl]pyridinato-N,C 2’}Iridium(III) acetylacetonate (abbreviation: [Ir(p-PF-ph)2(acac)]), bis(2-phenylbenzothiazolato-N,C 2’ ) iridium(III) acetylacetonate (abbreviated as [Ir(bt)2(acac)]), as well as rare earth metal complexes such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviated as [Tb(acac)3(Phen)]).

[0102] <Phosphorescent materials (570nm to 750nm: yellow or red)> Examples of phosphorescent materials that exhibit yellow or red color and have an emission spectrum with a peak wavelength of 570 nm or more and 750 nm or less include the following materials.

[0103] For example, pyrimidinato]iridium(III) such as (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), and (dipivaloylmethanato)bis[4,6-di(naphthalen-1-yl)pyrimidinato]iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]). Organometallic complexes with an imidine skeleton, (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridium(III) (abbreviation: [Ir(tppr)2(dpm)]), and bis{4,6-dimethyl-2-[3-(3,5-dimethylphenyl)-5-phenyl-2-pyrazinyl-κN]phenyl-κC}(2,6-dimethyl-3,5-heptanedionato-κN). 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-pyrazinyl-κN]phenyl-κC}(2,2,6,6-tetramethyl-3,5-heptanedionato-κ) 2 O,O')iridium(III) (abbreviation: [Ir(dmdppr-dmCP)2(dpm)]), bis[2-(5-(2,6-dimethylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN)-4,6-dimethylphenyl-κC](2,2',6,6'-tetramethyl-3,5-heptadionato-κ20,0')iridium(III) (abbreviation: [Ir(dmdppr-dmp)2(dpm)]), (acetylacetonato)bis[2-methyl-3-phenylquinoxalinato-N,C 2’ ]iridium(III) (abbreviation: [Ir(mpq)2(acac)]), (acetylacetonato)bis(2,3-diphenylquinoxalinato-N,C 2’)iridium(III) (abbreviation: [Ir(dpq)2(acac)]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq)2(acac)]), or organometallic complexes with a pyrazine skeleton such as tris(1-phenylisoquinolinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(piq)3]), bis(1-phenylisoquinolinato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(piq)2(acac)]), bis[4,6-dimethyl-2-(2-quinolinyl-κN)phenyl-κC](2,4-pentanedionato-κ 2 These include organometallic complexes with a pyridine skeleton, such as (O,O')iridium(III) (abbreviation: [Ir(dmpqn)2(acac)]), platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrinplatinum(II) (abbreviation: [PtOEP]), and rare earth metal complexes such as tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: [Eu(DBM)3(Phen)]) and tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: [Eu(TTA)3(Phen)]).

[0104] ≪TADF material≫ The following materials can be used as TADF materials. TADF materials are materials that have a small difference between the S1 level and the T1 level (preferably 0.2 eV or less), can upconvert a triplet excited state to a singlet excited state with a small amount of thermal energy (reverse intersystem crossing), and efficiently emit light (fluorescence) from the singlet excited state. Conditions for efficiently obtaining thermally activated delayed fluorescence include an energy difference between the triplet excited energy level and the singlet excited energy level of 0 eV or more and 0.2 eV or less, preferably 0 eV or more and 0.1 eV or less. Delayed fluorescence in TADF materials refers to light emission that has a spectrum similar to that of normal fluorescence but has a significantly long lifetime. Its lifetime is 1×10 -6 seconds or more, preferably 1 x 10 -3 More than a second.

[0105] Examples of TADF materials include fullerene or its derivatives, acridine derivatives such as proflavine, eosin, etc. Also included are metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd). Examples of metal-containing porphyrins include protoporphyrin-tin fluoride complex (abbreviation: SnF2(Proto IX)), mesoporphyrin-tin fluoride complex (abbreviation: SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (abbreviation: SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (abbreviation: SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complex (abbreviation: SnF2(OEP)), etioporphyrin-tin fluoride complex (abbreviation: SnF2(Etio I)), and octaethylporphyrin-platinum chloride complex (abbreviation: PtCl2OEP).

[0106] [ka]

[0107] Other examples include 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenyl 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[4 -(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracen]-10'-one (abbreviation: ACRSA), 4-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)benzofuro[3,2-d]pyrimidine (abbreviation: 4PCCzBfpm), 4-[4-(9'-phenyl Heterocyclic compounds having a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring, such as 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9′-phenyl-2,3′-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), may also be used.

[0108] In addition, a substance in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded is particularly preferable because the donor property of the π-electron-rich heteroaromatic ring and the acceptor property of the π-electron-deficient heteroaromatic ring are both strengthened, and the energy difference between the singlet excited state and the triplet excited state is reduced.

[0109] [ka]

[0110] In addition to the above, examples of materials capable of converting triplet excitation energy into luminescence include nanostructures of transition metal compounds having a perovskite structure. Nanostructures of metal halide perovskites are particularly preferred. Nanoparticles and nanorods are preferred as such nanostructures.

[0111] In the light-emitting layers (113, 113a, 113b, 113c), one or more substances having an energy gap larger than the energy gap of the light-emitting substance (guest material) may be selected and used as the organic compound (host material, etc.) used in combination with the above-mentioned light-emitting substance (guest material).

[0112] <Fluorescent host material> When the light-emitting substance used in the light-emitting layers (113, 113a, 113b, and 113c) is a fluorescent light-emitting substance, it is preferable to use, as the organic compound (host material) to be combined, an organic compound having a high energy level in a singlet excited state and a low energy level in a triplet excited state, or an organic compound having a high fluorescence quantum yield. Therefore, as long as the organic compound satisfies these conditions, a hole-transporting material (described above) or an electron-transporting material (described below) shown in this embodiment can be used.

[0113] Although some of the examples overlap with those described above, examples of the organic compound (host material) that can be preferably combined with the light-emitting substance (fluorescent light-emitting substance) include condensed polycyclic aromatic compounds such as anthracene derivatives, tetracene derivatives, phenanthrene derivatives, pyrene derivatives, chrysene derivatives, and dibenzo[g,p]chrysene derivatives.

[0114] Specific examples of organic compounds (host materials) that are preferably used in combination with fluorescent materials include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-anthryl)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 -(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: CzA1PA), 4-(10-phenyl-9-anthryl)triphenylamine (abbreviation: DPhPA), YGAPA, PCAPA, N,9-diphenyl-N-{4-[4-(10-phenyl-9-anthryl)phenyl]phenyl}-9H-carbazol-3-amine (abbreviation: PCAPBA), N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCAPA), 6,12-dimethoxy-5,1 1-Diphenylchrysene, N,N,N',N',N'',N'',N''',N'''-octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]-benzo[b]naphtho[1,2-d]furan (abbreviation: :2mBnfPPA), 9-phenyl-10-{4-(9-phenyl-9H-fluoren-9-yl)-biphenyl-4'-yl}-anthracene (abbreviation: FLPPA), 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 9,9'-bianthryl (abbreviation: BANT), 9,9'-(stilbene-3,3'-diyl)diphenanthrene (abbreviation: DPNS), 9,Examples include 9'-(stilbene-4,4'-diyl)diphenanthrene (abbreviated as DPNS2), 1,3,5-tri(1-pyrenyl)benzene (abbreviated as TPB3), 5,12-diphenyltetracene, and 5,12-bis(biphenyl-2-yl)tetracene.

[0115] <Phosphorescent host material> Furthermore, when the light-emitting substance used in the light-emitting layers (113, 113a, 113b, 113c) is a phosphorescent light-emitting substance, an organic compound having a triplet excitation energy greater than the triplet excitation energy (energy difference between the ground state and the triplet excited state) of the light-emitting substance can be selected as the organic compound (host material) to be combined. Note that when multiple organic compounds (for example, a first host material and a second host material (or assist material)) are used in combination with the light-emitting substance to form an exciplex, it is preferable to use these multiple organic compounds in combination with the phosphorescent light-emitting substance.

[0116] With this structure, it is possible to efficiently obtain light emission using Exciplex-Triplet Energy Transfer (ExTET), which is an energy transfer from an exciplex to a light-emitting substance. As a combination of multiple organic compounds, it is preferable to use one that easily forms an exciplex, and it is particularly preferable to combine a compound that easily accepts holes (hole transport material) with a compound that easily accepts electrons (electron transport material).

[0117] Although some of the examples overlap with those described above, examples of the organic compound (host material, assist material) from the viewpoint of a preferable combination with the light-emitting substance (phosphorescent light-emitting substance) include aromatic amines, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, zinc or aluminum-based metal complexes, oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyrimidine derivatives, triazine derivatives, pyridine derivatives, bipyridine derivatives, and phenanthroline derivatives.

[0118] Among the organic compounds, specific examples of aromatic amines and carbazole derivatives, which are organic compounds with high hole-transporting properties, include the same as the specific examples of the hole-transporting material described above, and any of these is preferable as the host material.

[0119] Specific examples of the dibenzothiophene derivatives and dibenzofuran derivatives, which are organic compounds with high hole transport properties among the above organic compounds, include 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), DBT3P-II, 2,8-dipheny Examples of suitable host materials include 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), and 4-[3-(triphenylen-2-yl)phenyl]dibenzothiophene (abbreviation: mDBTPTp-II).

[0120] Among the above, specific examples of metal complexes that are organic compounds (electron-transporting materials) with high electron-transporting properties include zinc- or aluminum-based metal complexes such as tris(8-quinolinolato)aluminum(III) (abbreviation: Alq), tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), and bis(8-quinolinolato)zinc(II) (abbreviation: Znq), as well as metal complexes having a quinoline skeleton or a benzoquinoline skeleton, all of which are preferable as the host material.

[0121] Other preferred host materials include metal complexes having oxazole- or thiazole-based ligands, such as bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO) and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ).

[0122] Specific examples of the organic compounds having high electron transport properties (electron transport materials) among the above organic compounds, such as oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, and phenanthroline derivatives, include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4- (5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (abbreviation: TAZ), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4 '-Bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOS), bathophenanthroline (abbreviation: Bphen), bathocuproine (abbreviation: BCP), 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: The compounds were synthesized from 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 7mDBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 7mDBTPDBq-II).h]quinoxaline (abbreviation: 6mDBTPDBq-II), and the like, all of which are preferred as host materials.

[0123] Specific examples of the heterocyclic compounds having a diazine skeleton, the heterocyclic compounds having a triazine skeleton, and the heterocyclic compounds having a pyridine skeleton, which are organic compounds with high electron transport properties (electron transport materials), include 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 2-{4-[3-(N-phenyl-9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), Examples of suitable host materials include 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), and 9-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02).

[0124] Other preferred host materials include polymer compounds such as poly(2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviation: PF-BPy).

[0125] Furthermore, bipolar 9-phenyl-9'-(4-phenyl-2-quinazolinyl)-3,3'-bi-9H-carbazole (abbreviation: PCCzQz), which is an organic compound having high hole-transporting properties and high electron-transporting properties, can also be used as a host material.

[0126] <Electron transport layer> The electron transport layers (114, 114a, 114b) are layers that transport electrons injected from the second electrode 102 or the charge generation layers (106, 106a, 106b) by the electron injection layers (115, 115a, 115b) described below to the light-emitting layers (113, 113a, 113b). The electron transport layers (114, 114a, 114b) are layers that contain an electron transport material. The electron transport material used in the electron transport layers (114, 114a, 114b) has an electron mobility of 1×10 or less at a square root of an electric field strength [V / cm] of 600. -6 cm 2 A substance having an electron mobility of 1 / Vs or higher is preferred. Note that other substances can be used as long as they have a higher electron transporting property than hole transporting property. The electron transport layers (114, 114a, 114b) function as single layers, but can also have a stacked structure of two or more layers as needed to improve device characteristics.

[0127] ≪Electron transport material≫ Examples of electron-transporting materials that can be used for the electron-transporting layer (114, 114a, 114b) include organic compounds having a structure in which an aromatic ring is condensed to a furan ring of a furodiazine skeleton, metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, and metal complexes having a thiazole skeleton, as well as materials with high electron-transporting properties (electron-transporting materials) such as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and π-electron-deficient heteroaromatic compounds including other nitrogen-containing heteroaromatic compounds.

[0128] Specific examples of the electron transport material include 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-{3-[3-(dibenzothiophene- 4-(4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), 4-[3-(dibenzothiophen-4-yl)phenyl]-8-(naphthalen-2-yl)-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8βN-4mDBtPBfpm), 3,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzofuro[2,3-b]pyrazine (abbreviation: 3,8mDBtP2B fpr), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviated as 4,8mDBtP2Bfpm), 9-[(3'-dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviated as 9mDBtBPNfpr), 8-[3'-(dibenzothiophen-4-yl)(1,1'-biphenyl-3-yl)]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviated as 9mDBtBPNfpr), 8-[(2,2'-binaphthalen)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 8-[(2,2'-binaphthalen)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 8-(1,1'-biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,Examples of suitable metal complexes include those having a quinoline or benzoquinoline skeleton, such as 2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), tris(8-quinolinolato)aluminum(III) (abbreviation: Alq3), Almq3, BeBq2, bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), and bis(8-quinolinolato)zinc(II) (abbreviation: Znq), and those having an oxazole or thiazole skeleton, such as bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO) and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ).

[0129] In addition to metal complexes, oxadiazole derivatives such as PBD, OXD-7, and CO11, triazole derivatives such as TAZ and p-EtTAZ, imidazole derivatives (including benzimidazole derivatives) such as TPBI and mDBTBIm-II, or oxazole derivatives such as BzOs, phenanthroline derivatives such as Bphen, BCP, and NBphen, quinoxaline derivatives such as 2mDBTPDBq-II, 2mDBTBPDBq-II, 2mCzBPDBq, 2CzPDBq-III, 7mDBTPDBq-II, and 6mDBTPDBq-II, or dibenzoquinoxaline derivatives, pyridine derivatives such as 35DCzPPy and TmPyPB, pyrimidine derivatives such as 4,6mPnP2Pm, 4,6mDBTP2Pm-II, and 4,6mCzP2Pm, and triazine derivatives such as PCCzPTzn and mPCCzPTzn-02 can be used as electron-transporting materials.

[0130] In addition, polymer compounds such as poly(2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviation: PF-BPy) can also be used as electron transport materials.

[0131] The electron transport layer (114, 114a, 114b) may not only be a single layer, but also have a structure in which two or more layers made of the above-mentioned substances are stacked.

[0132] <Electron injection layer> The electron injection layers (115, 115a, 115b) are layers containing a substance with high electron injection properties. The electron injection layers (115, 115a, 115b) are layers for increasing the efficiency of electron injection from the second electrode 102, and it is preferable to use a material for the second electrode 102 having a work function whose difference in LUMO level is small (0.5 eV or less) compared with that of the material for the electron injection layers (115, 115a, 115b). Therefore, the electron injection layer (115, 115a, 115b) may contain lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), 8-(quinolinolato)lithium (abbreviated as Liq), 2-(2-pyridyl)phenolatolithium (abbreviated as LiPP), 2-(2-pyridyl)-3-pyridinolatolithium (abbreviated as LiPPy), 4-phenyl-2-(2-pyridyl)phenolatolithium (abbreviated as LiPPP), lithium oxide (LiO x Alkali metals, alkaline earth metals, such as cesium carbonate, or compounds thereof can be used. Rare earth metal compounds, such as erbium fluoride (ErF3), can also be used. Electrides can also be used for the electron injection layers (115, 115a, 115b). Examples of electrides include a substance in which a high concentration of electrons is added to a mixed oxide of calcium and aluminum. The substances constituting the electron transport layers (114, 114a, 114b) described above can also be used.

[0133] The electron injection layer (115, 115a, 115b) may also be a composite material obtained by mixing an organic compound and an electron donor (donor). Such composite materials have excellent electron injection and electron transport properties because electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material that is excellent at transporting the generated electrons. Specifically, the electron transport materials (metal complexes, heteroaromatic compounds, etc.) used in the electron transport layer (114, 114a, 114b) described above can be used. The electron donor may be any substance that exhibits electron donating properties to the organic compound. Specific examples include alkali metals, alkaline earth metals, and rare earth metals, such as lithium, cesium, magnesium, calcium, erbium, and ytterbium. Alkali metal oxides or alkaline earth metal oxides are also preferred, such as lithium oxide, calcium oxide, and barium oxide. Lewis bases, such as magnesium oxide, can also be used. In addition, organic compounds such as tetrathiafulvalene (abbreviation: TTF) can also be used.

[0134] Alternatively, the electron injection layer (115, 115a, 115b) may be made of a composite material obtained by mixing an organic compound and a transition metal. The organic compound used here preferably has a LUMO (Lowest Unoccupied Molecular Orbital) level of -3.6 eV or more and -2.3 eV or less. A material having an unshared electron pair is also preferred.

[0135] Therefore, the organic compound is preferably a material having an unshared electron pair, such as a heterocyclic compound having a pyridine skeleton, a diazine skeleton (pyrimidine or pyrazine), or a triazine skeleton.

[0136] Examples of heterocyclic compounds having a pyridine skeleton include 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), bathocuproine (abbreviation: BCP), 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), and bathophenanthroline (abbreviation: Bphen).

[0137] Furthermore, examples of heterocyclic compounds having a diazine skeleton include 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), and 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h ]quinoxaline (abbreviation: 7mDBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 4-{3-[3'-(9H-carbazol-9-yl)]biphenyl-3-yl}benzofuro[3,2-d]pyrimidine (abbreviation: 4mCzBPBfpm), and the like.

[0138] Examples of heterocyclic compounds having a triazine skeleton include 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), and 2,4,6-tris(2-pyridyl)-1,3,5-triazine (abbreviation: 2Py3Tz).

[0139] As the transition metal, it is preferable to use a material belonging to Group 5, 7, 9 or 11 in the periodic table, such as Ag or Cu. In this case, the organic compound forms a single occupied molecular orbital (SOMO) with the transition metal.

[0140] For example, when light obtained from the light-emitting layer 113b is to be amplified, the optical distance between the second electrode 102 and the light-emitting layer 113b is preferably set to be less than ¼ of the wavelength λ of the light emitted by the light-emitting layer 113b. In this case, the optical distance can be adjusted by changing the film thickness of the electron-transporting layer 114b or the electron-injecting layer 115b.

[0141] Furthermore, as in the light-emitting device shown in FIG. 2D, by providing a charge generation layer 106 between two EL layers (103a, 103b), a structure in which multiple EL layers are stacked between a pair of electrodes (also called a tandem structure) can be formed.

[0142] <Charge generation layer> The charge generation layer 106 has a function of injecting electrons into the EL layer 103a and injecting holes into the EL layer 103b when a voltage is applied between the first electrode (anode) 101 and the second electrode (cathode) 102. The charge generation layer 106 may be a structure in which an electron acceptor is added to a hole transport material (also referred to as a P-type layer), or a structure in which an electron donor is added to an electron transport material (also referred to as an electron injection buffer layer). Alternatively, both of these structures may be stacked. Furthermore, an electron relay layer may be provided between the P-type layer and the electron injection buffer layer. By forming the charge generation layer 106 using the above-mentioned materials, it is possible to suppress an increase in driving voltage when EL layers are stacked.

[0143] When the charge generation layer 106 has a structure (P-type layer) in which an electron acceptor material is added to a hole-transporting material that is an organic compound, the material described in this embodiment can be used as the hole-transporting material. Examples of the electron acceptor material include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ) and chloranil. Examples of the electron acceptor material include oxides of metals belonging to Groups 4 to 8 of the periodic table. Specific examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide. The above-described electron acceptor materials may also be used. Materials for the P-type layer may be mixed together to form a mixed film, or single films containing each material may be stacked.

[0144] Furthermore, when the charge generation layer 106 has a structure in which an electron donor is added to an electron transporting material (electron injection buffer layer), the material described in this embodiment can be used as the electron transporting material. Furthermore, alkali metals, alkaline earth metals, rare earth metals, or metals belonging to Groups 2 and 13 of the periodic table, as well as oxides and carbonates thereof, can be used as the electron donor. Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide (LiO), cesium carbonate, or the like can be preferably used. Furthermore, an organic compound such as tetrathianaphthacene can also be used as the electron donor.

[0145] When an electron relay layer is provided between the P-type layer and the electron injection buffer layer in the charge generation layer 106, the electron relay layer contains at least a substance having electron transport properties and has the function of preventing interaction between the electron injection buffer layer and the P-type layer and smoothly transferring electrons. The LUMO level of the substance having electron transport properties contained in the electron relay layer is preferably between the LUMO level of the acceptor substance in the P-type layer and the LUMO level of the substance having electron transport properties contained in the electron transport layer in contact with the charge generation layer 106. The specific energy level of the LUMO level of the substance having electron transport properties used in the electron relay layer is −5.0 eV or higher, preferably −5.0 eV or higher and −3.0 eV or lower. Note that the substance having electron transport properties used in the electron relay layer is preferably a phthalocyanine-based material or a metal complex having a metal-oxygen bond and an aromatic ligand.

[0146] Although FIG. 2D shows a configuration in which two EL layers 103 are stacked, a stack structure of three or more EL layers may be formed by providing a charge generating layer between different EL layers.

[0147] <Substrate> The light-emitting device described in this embodiment mode can be formed on various substrates. Note that the type of substrate is not limited to a specific one. Examples of the substrate include a semiconductor substrate (for example, a single crystal substrate or a silicon substrate), an SOI substrate, a glass substrate, a quartz substrate, a plastic substrate, a metal substrate, a stainless steel substrate, a substrate having stainless steel foil, a tungsten substrate, a substrate having tungsten foil, a flexible substrate, a laminated film, paper containing a fibrous material, or a base film.

[0148] Examples of glass substrates include barium borosilicate glass, aluminoborosilicate glass, soda lime glass, etc. Examples of flexible substrates, laminated films, base films, etc. include plastics such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyethersulfone (PES), synthetic resins such as acrylic, polypropylene, polyester, polyvinyl fluoride, polyvinyl chloride, polyamide, polyimide, aramid, epoxy, inorganic vapor deposition films, and paper.

[0149] The light-emitting device described in this embodiment can be manufactured by a vacuum process such as evaporation, a spin coating method, or a solution process such as an ink-jet method. When an evaporation method is used, a physical vapor deposition (PVD) method such as sputtering, ion plating, ion beam evaporation, molecular beam evaporation, or vacuum evaporation, or a chemical vapor deposition (CVD) method can be used. In particular, the functional layers (hole injection layers (111, 111a, 111b), hole transport layers (112, 112a, 112b), light-emitting layers (113, 113a, 113b, 113c), electron transport layers (114, 114a, 114b), electron injection layers (115, 115a, 115b)) and charge generation layers (106, 106a, 106b) included in the EL layer of the light-emitting device can be formed by a deposition method (vacuum deposition method, etc.), a coating method (dip coating method, die coating method, bar coating method, spin coating method, spray coating method, etc.), a printing method (inkjet method, screen (stencil printing) method, offset (lithographic printing) method, flexography (relief printing) method, gravure method, microcontact method, etc.), etc.

[0150] When applying the above-mentioned coating method, printing method, or other film formation method, it is possible to use high molecular weight compounds (oligomers, dendrimers, polymers, etc.), medium molecular weight compounds (compounds in the intermediate range between low molecular weight and high molecular weight: molecular weight of 400 to 4000), inorganic compounds (quantum dot materials, etc.), etc. As quantum dot materials, colloidal quantum dot materials, alloy-type quantum dot materials, core-shell type quantum dot materials, core-type quantum dot materials, etc. can be used.

[0151] The functional layers constituting the EL layer (103, 103a, 103b, 103c) of the light-emitting device shown in this embodiment (hole injection layer (111, 111a, 111b), hole transport layer (112, 112a, 112b), light-emitting layer (113, 113a, 113b, 113c), electron transport layer (114, 114a, 114b), electron injection layer (115, 115a, 115b)) or charge generation layer (106, 106a, 106b) are not limited to the materials shown in this embodiment, and other materials can be used in combination as long as they can fulfill the function of each layer.

[0152] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0153] (Embodiment 2) In this embodiment, a specific structural example of a light-emitting device (also referred to as a display panel) which is one embodiment of the present invention and a manufacturing method thereof will be described.

[0154] <Configuration Example 1 of Light-Emitting Device 700> 3A includes a light-emitting device 550B, a light-emitting device 550G, a light-emitting device 550R, and a partition wall 528. The light-emitting device 550B, the light-emitting device 550G, the light-emitting device 550R, and the partition wall 528 are formed on a functional layer 520 provided on a first substrate 510. The functional layer 520 includes a driving circuit GD, a driving circuit SD, a pixel circuit, and the like, each of which is composed of a plurality of transistors, as well as wiring and the like that electrically connects these components. These driving circuits are electrically connected to the light-emitting device 550B, the light-emitting device 550G, and the light-emitting device 550R, respectively, and can drive these components.

[0155] Light-emitting device 550B, light-emitting device 550G, and light-emitting device 550R have the device structure shown in Embodiment 1. In particular, the EL layer 103 in the structure shown in FIG.

[0156] Light-emitting device 550B includes electrode 551B, electrode 552, EL layer 103B, oxidation-resistant layer 105B, and blocking layer 107. The specific configuration of each layer is as described in embodiment 1. EL layer 103B has a stacked structure composed of multiple layers with different functions, including light-emitting layer 113B. The oxidation-resistant layer 105B is included in EL layer 103B. While FIG. 3A illustrates only the hole injection / transport layer 104B and the oxidation-resistant layer 105B among the layers included in EL layer 103B, including light-emitting layer 113B, the present invention is not limited thereto. Hole injection / transport layer 104B represents a layer having the functions of the hole injection layer and hole transport layer described in embodiment 1 and may have a stacked structure. Throughout this specification, the term "hole injection / transport layer" can be interpreted in this way in any light-emitting device. Similarly, the electron injection / transport layer also functions as an electron injection layer and an electron transport layer and may have a stacked structure.

[0157] The blocking layer 107 is formed to cover the EL layer 103B formed over the electrode 551B. As shown in FIG. 3A, the EL layer 103B has side surfaces (or end surfaces). Therefore, the blocking layer 107 is formed in contact with the side surfaces (or end surfaces) of the EL layer 103B. This can prevent oxygen, moisture, or these constituent elements from entering the EL layer 103B from the side surfaces. The hole-transporting material described in Embodiment 1 can be used for the blocking layer 107.

[0158] Furthermore, the electrode 552 is formed on the block layer 107. The electrodes 551B and 552 overlap each other in an overlapping region. The EL layer 103B is provided between the electrodes 551B and 552. Therefore, the electrode 552 is in contact with the side surface (or end portion) of the EL layer 103B via the block layer 107. This prevents an electrical short circuit between the EL layer 103B and the electrode 552, more specifically, between the hole injection / transport layer 104B of the EL layer 103B and the electrode 552.

[0159] 3A has the same configuration as the EL layers 103, 103a, 103b, and 103c described in Embodiment 1. Furthermore, the EL layer 103B can emit, for example, blue light.

[0160] Light-emitting device 550G includes electrode 551G, electrode 552, EL layer 103G, oxidation-resistant layer 105G, and blocking layer 107. The specific configuration of each layer is as described in embodiment 1. EL layer 103G has a stacked structure including multiple layers with different functions, including light-emitting layer 113G. EL layer 103G also includes oxidation-resistant layer 105G. While FIG. 3A illustrates only the hole injection / transport layer 104G and oxidation-resistant layer 105G among the layers included in EL layer 103G including light-emitting layer 113G, the present invention is not limited thereto. Hole injection / transport layer 104G functions as the hole injection layer and hole transport layer described in embodiment 1, and may have a stacked structure.

[0161] The blocking layer 107 is formed to cover the EL layer 103G formed over the electrode 551G. As shown in FIG. 3A, the EL layer 103G has side surfaces (or end surfaces). Therefore, the blocking layer 107 is formed in contact with the side surfaces (or end surfaces) of the EL layer 103G as well. This can prevent oxygen, moisture, or these constituent elements from entering the EL layer 103G from the side surfaces. The hole-transporting material described in Embodiment 1 can be used for the blocking layer 107.

[0162] Furthermore, the electrode 552 is formed on the block layer 107. The electrodes 551G and 552 overlap each other in an overlapping region. The EL layer 103G is provided between the electrodes 551G and 552. Therefore, the electrode 552 is in contact with the side surface of the EL layer 103G via the block layer 107. This prevents an electrical short circuit between the EL layer 103G and the electrode 552, more specifically, between the hole injection / transport layer 104G of the EL layer 103G and the electrode 552.

[0163] 3A has the same configuration as the EL layers 103, 103a, 103b, and 103c described in Embodiment 1. The EL layer 103G can emit, for example, green light.

[0164] Light-emitting device 550R includes electrode 551R, electrode 552, EL layer 103R, oxidation-resistant layer 105R, and blocking layer 107. The specific configuration of each layer is as described in embodiment 1. EL layer 103R has a stacked structure including multiple layers with different functions, including light-emitting layer 113R. EL layer 103R also includes oxidation-resistant layer 105R. While FIG. 3A illustrates only the hole injection / transport layer 104R and oxidation-resistant layer 105R among the layers included in EL layer 103R including light-emitting layer 113R, the present invention is not limited thereto. Hole injection / transport layer 104R functions as the hole injection layer and hole transport layer described in embodiment 1, and may have a stacked structure.

[0165] The blocking layer 107 is formed to cover the EL layer 103R formed on the electrode 551R. As shown in FIG. 3A, the EL layer 103R has side surfaces (or end surfaces). Therefore, the blocking layer 107 is formed in contact with the side surfaces (or end surfaces) of the EL layer 103R as well. This can prevent oxygen, moisture, or these constituent elements from penetrating into the EL layer 103R from the side surfaces. The hole-transporting material described in Embodiment 1 can be used for the blocking layer 107.

[0166] Furthermore, the electrode 552 is formed on the block layer 107. The electrodes 551R and 552 overlap each other in an overlapping region. The EL layer 103R is provided between the electrodes 551R and 552. Therefore, the electrode 552 is in contact with the side surface of the EL layer 103R via the block layer 107. This prevents an electrical short circuit between the EL layer 103R and the electrode 552, more specifically, between the hole injection / transport layer 104R of the EL layer 103R and the electrode 552.

[0167] 3A has the same configuration as the EL layers 103, 103a, 103b, and 103c described in Embodiment 1. Furthermore, the EL layer 103R can emit, for example, red light.

[0168] A gap 580 is provided between each of the EL layers 103B, 103G, and 103R. In each EL layer, the hole injection layer included in the hole transport region located between the anode and the light-emitting layer, in particular, often has high conductivity, and therefore may cause crosstalk if formed as a layer common to adjacent light-emitting devices. Therefore, by providing a gap 580 between each EL layer as shown in this configuration example, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0169] In a high-resolution light-emitting device (display panel) exceeding 1000 ppi, if electrical conduction is found between EL layer 103B, EL layer 103G, and EL layer 103R, crosstalk occurs, narrowing the color gamut that can be displayed by the light-emitting device. By providing gap 580 in a high-resolution display panel exceeding 1000 ppi, preferably a high-resolution display panel exceeding 2000 ppi, and more preferably an ultra-high-resolution display panel exceeding 5000 ppi, it is possible to provide a display panel that can display vivid colors.

[0170] Fig. 3B is a top view in the XY direction of the light-emitting device shown in Fig. 3A, and a cross-sectional view taken along line Y1-Y2 corresponds to Fig. 3A. As shown in Fig. 3B, partition wall 528 has openings 528B, 528G, and 528R. Note that, as shown in Fig. 3A, opening 528B overlaps with electrode 551B, opening 528G overlaps with electrode 551G, and opening 528R overlaps with electrode 551R.

[0171] In addition, since pattern formation is performed by photolithography in the separation process of these EL layers (EL layer 103B, EL layer 103G, and EL layer 103R), a high-definition light-emitting device (display panel) can be manufactured. Furthermore, the ends of the EL layers (side surfaces of the laminated structure constituting the EL layers) processed by pattern formation by photolithography have a shape that has approximately the same surface (or is located on approximately the same plane). Furthermore, in this case, the width of the gap 580 provided between each EL layer is preferably 5 μm or less, and more preferably 1 μm or less.

[0172] In the EL layer, the hole injection layer included in the hole transport region located between the anode and the light-emitting layer, in particular, often has high conductivity, and therefore, if it is formed as a layer common to adjacent light-emitting devices, it may cause crosstalk. Therefore, by separating the EL layer by pattern formation using photolithography as shown in this configuration example, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0173] <Example 1 of manufacturing method of light emitting device> 4A, an electrode 551B, an electrode 551G, and an electrode 551R are formed. For example, a conductive film is formed on the functional layer 520 formed on the first substrate 510, and processed into a predetermined shape using photolithography.

[0174] The conductive film can be formed by sputtering, chemical vapor deposition (CVD), vacuum evaporation, pulsed laser deposition (PLD), atomic layer deposition (ALD), etc. CVD methods include plasma enhanced chemical vapor deposition (PECVD) and thermal CVD. Metal organic chemical vapor deposition (MOCVD) is another type of thermal CVD.

[0175] In addition to the photolithography method described above, the conductive film may be processed using nanoimprinting, sandblasting, lift-off, or other methods. Furthermore, island-shaped thin films may be directly formed using a film formation method that uses a shielding mask such as a metal mask. Here, "island-shaped" refers to a state in which the thin film is separated from layers made of the same material and formed in the same process, as viewed from above.

[0176] There are two typical photolithography methods: one is to form a resist mask on the thin film to be processed, process the thin film by etching or the like, and then remove the resist mask; the other is to form a photosensitive thin film, and then process the thin film into the desired shape by exposure and development.

[0177] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other light sources that can be used include ultraviolet light, KrF laser light, and ArF laser light. Exposure can also be performed using immersion exposure technology. Extreme ultraviolet (EUV) light or X-rays can also be used as the light used for exposure. Instead of light used for exposure, an electron beam can also be used. Extreme ultraviolet light, X-rays, or an electron beam are preferred because they enable extremely fine processing. When exposure is performed by scanning a beam such as an electron beam, a photomask is not required.

[0178] For etching the thin film using a resist mask, dry etching, wet etching, sandblasting, or the like can be used.

[0179] 4B , a partition wall 528 is formed between the electrode 551B and the electrode 551G. For example, an insulating film is formed to cover the electrode 551B, the electrode 551G, and the electrode 551R, and openings are formed by photolithography to expose parts of the electrode 551B, the electrode 551G, and the electrode 551R, thereby forming the partition wall 528. Examples of materials that can be used for the partition wall 528 include inorganic materials, organic materials, and composite materials of inorganic and organic materials. Specifically, the partition wall 528 can be formed using an inorganic oxide film, an inorganic nitride film, an inorganic oxynitride film, or the like, or a laminate structure in which a plurality of films selected from these are stacked. More specifically, the partition wall 528 can be formed using a silicon oxide film, a film containing acrylic, a film containing polyimide, or the like, or a laminate structure in which a plurality of films selected from these are stacked.

[0180] 5A , an EL layer 103B is formed on the electrodes 551B, 551G, 551R, and the partition walls 528. In this configuration example, the EL layer 103B includes a light-emitting layer 113B, a hole injection / transport layer 104B, and an oxidation-resistant layer 105B. For example, the EL layer 103B is formed by vacuum deposition on the electrodes 551B, 551G, 551R, and the partition walls 528 so as to cover them.

[0181] The oxidation-resistant layer 105B is formed using an oxidation-resistant material. Specifically, a composite material in which an electron acceptor material is added to a hole-transporting material, which is an organic compound, as described in Embodiment 1 as a material that can be used for the charge generation layer of the EL layer, or a stacked structure of a hole-transporting material and an electron acceptor material can be used. Furthermore, the materials described in Embodiment 1 as organic acceptor materials used for the hole injection layer can be used as the electron acceptor material. By using a metal oxide as the electron acceptor material, oxidation resistance can be improved.

[0182] Examples of metal oxides include oxides of metals belonging to Groups 4 to 8 of the periodic table. Specific examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide. Furthermore, materials listed as hole-transporting materials can be used as organic compounds.

[0183] By adjusting the composition of the metal oxide and organic compound contained in oxidation-resistant layer 105B to a predetermined value, it is possible to prevent the oxidation-resistant layer 105B from dissolving when a resist is formed on oxidation-resistant layer 105B in a subsequent process. Regarding the composition of the metal oxide and organic compound used in oxidation-resistant layer 105B, taking into consideration the film thickness and transmittance of oxidation-resistant layer 105B, it is preferable that the weight of the organic compound is 1 / 100 to 100 times, and more preferably 1 / 20 to 20 times, the weight of the metal oxide.

[0184] Next, as shown in FIG. 5B, the EL layer 103B on the electrode 551B is processed into a predetermined shape. For example, a resist is formed using photolithography, and the EL layer 103B on the electrode 551G and the EL layer 103B on the electrode 551R are removed by etching to process into a shape with sides (or with exposed sides) or a strip-like shape extending in a direction intersecting the paper surface. Specifically, dry etching is performed using a resist REG formed on the EL layer 103B overlapping the electrode 551B (see FIG. 5B). The partition wall 528 can be used as an etching stopper.

[0185] 5C , with the resist REG still formed, the EL layer 103G (including the light-emitting layer 113G, the hole injection / transport layer 104G, and the oxidation-resistant layer 105G) is formed on the resist REG, the electrode 551G, the electrode 551R, and the partition wall 528. For example, the EL layer 103G is formed by vacuum deposition on the resist REG, the electrode 551G, the electrode 551R, and the partition wall 528 so as to cover them. Note that the oxidation-resistant layer 105G is formed using a composite material containing a metal oxide and an organic compound (hole transport material), similar to the oxidation-resistant layer 105B.

[0186] Next, as shown in FIG. 6A, the EL layer 103G on the electrode 551G is processed into a predetermined shape. For example, a resist is formed on the EL layer 103G on the electrode 551G using photolithography, and the EL layer 103G on the electrode 551B and the EL layer 103G on the electrode 551R are removed by etching to process into a shape with sides (or with exposed sides) or a strip-like shape extending in a direction intersecting the paper surface. Specifically, dry etching is performed using a resist REG formed on the EL layer 103G overlapping the electrode 551G. The partition wall 528 can be used as an etching stopper.

[0187] 6B, with the resist REG formed on the electrode 551B and the electrode 551G, the EL layer 103R (including the light-emitting layer 113R, the hole injection / transport layer 104R, and the oxidation-resistant layer 105R) is formed on the resist REG, the electrode 551R, and the partition wall 528. For example, the EL layer 103R is formed by vacuum deposition on the electrode 551R, the resist REG, and the partition wall 528 so as to cover them. Note that the oxidation-resistant layer 105R is formed using a composite material containing a metal oxide and an organic compound (hole transport material), similar to the oxidation-resistant layer 105B.

[0188] Next, as shown in FIG. 6C, the EL layer 103R on the electrode 551R is processed into a predetermined shape. For example, a resist is formed on the EL layer 103R on the electrode 551R using photolithography, and the EL layer 103R on the electrode 551B and the EL layer 103R on the electrode 551G are removed by etching to process into a shape with sides (or with exposed sides) or a strip-like shape extending in a direction intersecting the paper surface. Specifically, dry etching is performed using a resist REG formed on the EL layer 103R overlapping the electrode 551R. The partition wall 528 can be used as an etching stopper.

[0189] As shown in Figures 5A, 5B, 5C, 6A, 6B, and 6C, it is preferable to first form the hole injection / transport layer 104B, the light-emitting layer 113B, and the oxidation-resistant layer 105B on the electrode 551B, then form the hole injection / transport layer 104G, the light-emitting layer 113G, and the oxidation-resistant layer 105G on the electrode 551G, and finally form the hole injection / transport layer 104R, the light-emitting layer 113R, and the oxidation-resistant layer 105R on the electrode 551R.

[0190] In the above-described process, when the hole injection / transport layer 104B, the light-emitting layer 113B, and the oxidation-resistant layer 105B on the electrode 551G and the hole injection / transport layer 104B, the light-emitting layer 113B, and the oxidation-resistant layer 105B on the electrode 551R are removed by etching, the surfaces of the electrodes 551G and 551R are exposed to etching. Furthermore, when the hole injection / transport layer 104G, the light-emitting layer 113G, and the oxidation-resistant layer 105G on the electrode 551G are removed by etching, the surface of the electrode 551R is exposed to etching. Therefore, the surface of the electrode 551B is not exposed to etching, but the surface of the electrode 551G is exposed to etching once, and the surface of the electrode 551R is exposed to etching twice.

[0191] Exposure of the electrode surface to etching may cause damage to the electrode surface. Furthermore, forming a light-emitting device using an electrode with surface damage may deteriorate the characteristics of the light-emitting device. The degree to which the surface condition of the electrode affects the characteristics of the light-emitting device depends on the structure of the light-emitting device, the materials used, etc. Comparing light-emitting device 550B, light-emitting device 550G, and light-emitting device 550R, the surface condition of the electrode may be most likely to affect the characteristics of light-emitting device 550B.

[0192] In this case, by first forming the hole injection / transport layer 104B, the light-emitting layer 113B, and the oxidation-resistant layer 105B on the electrode 551B, the surface of the electrode 551B can be prevented from being exposed to etching, and deterioration of the characteristics of the light-emitting device 550B, which is most susceptible to the surface condition of the electrode, can be prevented.

[0193] Next, as shown in FIG. 7A, a block layer 107 is formed on the oxidation-resistant layer 105B, the oxidation-resistant layer 105G, the oxidation-resistant layer 105R, and the partition wall 528. For example, by using a vacuum deposition method, the block layer 107 is formed on the oxidation-resistant layer 105B, the oxidation-resistant layer 105G, the oxidation-resistant layer 105R, and the partition wall 528 so as to cover them. In this case, the block layer 107 is formed in contact with the side surfaces of the EL layers (103B, 103G, and 103R) as shown in FIG. 7A. This makes it possible to prevent oxygen, moisture, or their constituent elements from penetrating into the interior of the EL layers (103B, 103G, and 103R) from the side surfaces. Note that the hole-transporting material described in Embodiment 1 can be used as the material for the block layer 107.

[0194] Next, as shown in FIG. 7B , an electrode 552 is formed on the block layer 107. The electrode 552 is formed by, for example, vacuum deposition. The electrode 552 is formed on the block layer 107. The electrode 552 has a structure in which the electrode 552 contacts the side surface of each EL layer (103B, 103G, 103R) via the block layer 107. This prevents electrical short-circuiting between each EL layer (103B, 103G, 103R) and the electrode 552, more specifically, between the hole injection / transport layers (104B, 104G, 104R) of each EL layer (103B, 103G, 103R) and the electrode 552.

[0195] Through the above steps, EL layers 103B, 103G, and 103R in light-emitting devices 550B, 550G, and 550R can be separated and processed, respectively.

[0196] In addition, since pattern formation is performed by photolithography in the separation processing of these EL layers (EL layer 103B, EL layer 103G, and EL layer 103R), a high-definition light-emitting device (display panel) can be manufactured. Furthermore, the edges of the EL layers (side surfaces of the laminated structure constituting the EL layers) processed by pattern formation by photolithography have a shape that has approximately the same surface (or is located on approximately the same plane).

[0197] In the EL layer, the hole injection layer included in the hole transport region located between the anode and the light-emitting layer, in particular, often has high conductivity, and therefore, if it is formed as a layer common to adjacent light-emitting devices, it may cause crosstalk. Therefore, by separating the EL layer by pattern formation using photolithography as shown in this configuration example, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0198] In this specification, etc., a device fabricated using a metal mask or FMM (fine metal mask, high-resolution metal mask) may be referred to as a device with an MM (metal mask) structure. Also, in this specification, etc., a device fabricated without using a metal mask or FMM may be referred to as a device with an MML (metal maskless) structure.

[0199] In this specification, a structure in which different light-emitting layers are formed or different light-emitting layers are painted for each color light-emitting device (here, blue (B), green (G), and red (R)) may be referred to as an SBS (Side By Side) structure. In this specification, a light-emitting device that can emit white light may be referred to as a white light-emitting device. In addition, a white light-emitting device can be made into a light-emitting device that displays full color by combining it with a colored layer (for example, a color filter).

[0200] Furthermore, light-emitting devices can be broadly divided into single-structure and tandem-structure devices. A single-structure device has one EL layer between a pair of electrodes, and the EL layer preferably includes one or more light-emitting layers. To obtain white light emission, two or more light-emitting layers may be selected so that the light emitted from each of the two or more light-emitting layers has a complementary color relationship. For example, by making the emission color of the first light-emitting layer and the emission color of the second light-emitting layer complementary, a configuration in which the entire light-emitting device emits white light can be obtained. The same applies to light-emitting devices having three or more light-emitting layers.

[0201] A tandem-structure device preferably has two or more EL layers between a pair of electrodes, and each EL layer preferably includes one or more light-emitting layers. To obtain white light emission, light from the light-emitting layers of multiple EL layers may be combined to obtain white light emission. The configuration for obtaining white light emission is the same as that of the single-structure device. In a tandem-structure device, it is preferable to provide an intermediate layer such as a charge-generating layer between the multiple EL layers.

[0202] Furthermore, when comparing the above-mentioned white light-emitting device (single structure or tandem structure) with a light-emitting device having an SBS structure, the light-emitting device having an SBS structure can reduce power consumption compared to the white light-emitting device. If you want to keep power consumption low, it is preferable to use a light-emitting device having an SBS structure. On the other hand, the manufacturing process of a white light-emitting device is simpler than that of a light-emitting device having an SBS structure, so it is preferable because it can reduce manufacturing costs or increase manufacturing yields.

[0203] <Configuration Example 2 of Light-Emitting Device 700> 8 includes a light-emitting device 550B, a light-emitting device 550G, a light-emitting device 550R, and a partition wall 528. The light-emitting device 550B, the light-emitting device 550G, the light-emitting device 550R, and the partition wall 528 are formed on a functional layer 520 provided on a first substrate 510. The functional layer 520 includes a driving circuit GD, a driving circuit SD, a pixel circuit, and the like, each of which is composed of a plurality of transistors, as well as wiring and the like that electrically connects these components. These driving circuits are electrically connected to the light-emitting device 550B, the light-emitting device 550G, and the light-emitting device 550R, respectively, and can drive these components.

[0204] Light-emitting device 550B, light-emitting device 550G, and light-emitting device 550R have the device structure shown in Embodiment 1. In particular, the EL layer 103 in the structure shown in FIG.

[0205] The specific configurations of the light emitting devices shown in FIG. 8 are the same as those of the light emitting device 550B, the light emitting device 550G, and the light emitting device 550R described with reference to FIG.

[0206] 8, there is a gap 580 between each light emitting device, for example, between light emitting device 550B and light emitting device 550G. Therefore, an insulating layer 540 is formed in this gap 580.

[0207] For example, the EL layer 103B (including the hole injection / transport layer 104B and the oxidation-resistant layer 105B), the EL layer 103G (including the hole injection / transport layer 104G and the oxidation-resistant layer 105G), and the EL layer 103R (including the hole injection / transport layer 104R and the oxidation-resistant layer 105R) can be separately formed by patterning using photolithography, and then the insulating layer 540 can be formed in the gap 580 on the partition wall 528 by patterning using photolithography. Furthermore, an electrode 552 can be formed on the EL layers (103B, 103G, 103R) and the insulating layer 540.

[0208] In this configuration, since the EL layers are separated by the insulating layer 540, the block layer (107 in FIG. 3A) shown in Configuration Example 1 is not necessary.

[0209] Furthermore, since each EL layer (EL layer 103B, EL layer 103G, and EL layer 103R) in this configuration is patterned using photolithography during separation processing, the ends of the processed EL layers (the side surfaces of the laminated structure that constitutes the EL layer) have a shape that has approximately the same surface (or is located on approximately the same plane).

[0210] In the EL layer, the hole injection layer included in the hole transport region located between the anode and the light-emitting layer, in particular, often has high conductivity, and therefore, if it is formed as a layer common to adjacent light-emitting devices, it may cause crosstalk. Therefore, by separating the EL layer by pattern formation using photolithography as shown in this configuration example, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0211] <Configuration Example 3 of Light-Emitting Device 700> 9A includes a light-emitting device 700 including a light-emitting device 550B, a light-emitting device 550G, a light-emitting device 550R, and a partition wall 528. The light-emitting device 550B, the light-emitting device 550G, the light-emitting device 550R, and the partition wall 528 are formed on a functional layer 520 provided on a first substrate 510. The functional layer 520 includes a driving circuit GD, a driving circuit SD, a pixel circuit, and the like, each of which is configured with a plurality of transistors, as well as wiring and the like that electrically connects these components. These driving circuits are electrically connected to the light-emitting device 550B, the light-emitting device 550G, and the light-emitting device 550R, respectively, and can drive these components.

[0212] Light-emitting device 550B, light-emitting device 550G, and light-emitting device 550R have the device structure shown in Embodiment 1. In particular, the light-emitting devices share EL layer 103 having the structure shown in FIG. 2B, a so-called tandem structure.

[0213] Light-emitting device 550B has electrode 551B, electrode 552, EL layers (103P, 103Q (including oxidation-resistant layer 105Q)), charge generation layer 106B, and blocking layer 107, and has the layered structure shown in FIG. 9A. The specific configuration of each layer is as described in embodiment 1. Electrode 551B and electrode 552 overlap. EL layer 103P and EL layer 103Q are layered with charge generation layer 106B sandwiched between them, and EL layer 103P, EL layer 103Q, and charge generation layer 106B are located between electrode 551B and electrode 552. EL layers 103P and 103Q have a layered structure consisting of multiple layers with different functions, including light-emitting layers (113P, 113Q), similar to EL layers 103, 103a, 103b, and 103c described in embodiment 1. The EL layer 103P can emit, for example, blue light, and the EL layer 103Q can emit, for example, yellow light.

[0214] 9A shows only the light-emitting layer 113P and the hole injection / transport layer 104P among the layers included in the EL layer 103P, and only the light-emitting layer 113Q, the hole injection / transport layer 104Q, and the oxidation-resistant layer 105Q among the layers included in the EL layer 103Q. Therefore, hereinafter, when it is possible to include the layers included in each EL layer, the explanation will be made using the EL layer (EL layer 103P, EL layer 103Q) for convenience.

[0215] The blocking layer 107 is formed to cover the EL layer 103P, the EL layer 103Q, and the charge generation layer 106B formed on the electrode 551B. As shown in FIG. 9A, the EL layer 103P, the EL layer 103Q, and the charge generation layer 106B have side surfaces (or ends). Therefore, the blocking layer 107 is formed in contact with the side surfaces (or ends) of the EL layer 103P, the EL layer 103Q, and the charge generation layer 106B. This can prevent oxygen, moisture, or their constituent elements from penetrating into the EL layer 103P, the EL layer 103Q, and the charge generation layer 106B from their respective side surfaces. The blocking layer 107 can be formed using the hole-transporting material described in Embodiment 1.

[0216] The electrode 552 is formed on the block layer 107. The electrodes 551B and 552 overlap each other. The EL layer 103P, the EL layer 103Q, and the charge generation layer 106B are disposed between the electrodes 551B and 552. Therefore, the electrode 552 is in contact with the side surfaces (or ends) of the EL layer 103P, the EL layer 103Q, and the charge generation layer 106B via the block layer 107. This prevents electrical short-circuiting between the EL layer 103P and the electrode 552, more specifically, between the hole injection / transport layer 104P and the electrode 552 of the EL layer 103P, or between the EL layer 103Q and the electrode 552, or more specifically, between the hole injection / transport layer 104Q and the electrode 552 of the EL layer 103Q, or between the charge generation layer 106B and the electrode 552.

[0217] Light-emitting device 550G has electrode 551G, electrode 552, EL layers (103P, 103Q (including oxidation-resistant layer 105Q)), charge generation layer 106G, and blocking layer 107, and has the layered structure shown in FIG. 9A. The specific configuration of each layer is as shown in embodiment 1. Electrode 551G and electrode 552 overlap. EL layer 103P and EL layer 103Q are layered with charge generation layer 106G sandwiched between them, and EL layer 103P, EL layer 103Q, and charge generation layer 106G are located between electrode 551G and electrode 552.

[0218] The blocking layer 107 is formed to cover the EL layer 103P, the EL layer 103Q, and the charge generation layer 106G formed on the electrode 551G. As shown in FIG. 9A, the EL layer 103P, the EL layer 103Q, and the charge generation layer 106G have side surfaces (or ends). Therefore, the blocking layer 107 is formed in contact with the side surfaces (or ends) of the EL layer 103P, the EL layer 103Q, and the charge generation layer 106G. This can prevent oxygen, moisture, or their constituent elements from penetrating into the EL layer 103P, the EL layer 103Q, and the charge generation layer 106G from the side surfaces. The hole-transporting material described in Embodiment 1 can be used for the blocking layer 107.

[0219] The electrode 552 is formed on the block layer 107. The electrodes 551G and 552 overlap each other. The EL layer 103P, the EL layer 103Q, and the charge generation layer 106G are disposed between the electrodes 551G and 552. Therefore, the electrode 552 is in contact with the side surfaces (or ends) of the EL layer 103P, the EL layer 103Q, and the charge generation layer 106G via the block layer 107. This prevents electrical short-circuiting between the EL layer 103P and the electrode 552, more specifically, between the hole injection / transport layer 104P and the electrode 552 of the EL layer 103P, or between the EL layer 103Q and the electrode 552, more specifically, between the hole injection / transport layer 104Q and the electrode 552 of the EL layer 103Q, or between the charge generation layer 106G and the electrode 552.

[0220] Light-emitting device 550R has electrode 551R, electrode 552, EL layers (103P, 103Q (including oxidation-resistant layer 105Q)), charge generation layer 106R, and blocking layer 107, and has the laminated structure shown in FIG. 9A. The specific configuration of each layer is as shown in embodiment 1. Electrode 551R and electrode 552 overlap. EL layer 103P and EL layer 103Q are laminated with charge generation layer 106R sandwiched therebetween, and EL layer 103P, EL layer 103Q, and charge generation layer 106R are located between electrode 551R and electrode 552.

[0221] The blocking layer 107 is formed to cover the EL layer 103P, the EL layer 103Q, and the charge generation layer 106R formed on the electrode 551R. As shown in FIG. 9A, the EL layer 103P, the EL layer 103Q, and the charge generation layer 106R have side surfaces (or ends). Therefore, the blocking layer 107 is formed in contact with the side surfaces (or ends) of the EL layer 103P, the EL layer 103Q, and the charge generation layer 106R. This can prevent oxygen, moisture, or their constituent elements from penetrating into the EL layer 103P, the EL layer 103Q, and the charge generation layer 106R from the side surfaces. The hole-transporting material described in Embodiment 1 can be used for the blocking layer 107.

[0222] The electrode 552 is formed on the block layer 107. The electrodes 551R and 552 overlap each other. The EL layers (103P, 103Q) and the charge generation layer 106R are disposed between the electrodes 551R and 552. The electrode 552 is configured to contact the side surfaces (or ends) of the EL layers (103P, 103Q) and the charge generation layer 106R via the block layer 107. This prevents electrical short-circuiting between the EL layer 103P and the electrode 552, more specifically, between the hole injection / transport layer 104P and the electrode 552 of the EL layer 103P, or between the EL layer 103Q and the electrode 552, more specifically, between the hole injection / transport layer 104Q and the electrode 552 of the EL layer 103Q, or between the charge generation layer 106R and the electrode 552.

[0223] When the EL layer (103P, 103Q) and the charge generating layer 106 of each light-emitting device are processed separately for each light-emitting device, pattern formation is performed using photolithography, so that the ends of the processed EL layer (the sides of the laminated structure that constitutes the EL layer) have a shape that has approximately the same surface (or is located on approximately the same plane).

[0224] The EL layers (103P, 103Q) and charge generation layers 106 of each light-emitting device have a gap 580 between adjacent light-emitting devices. The hole injection layers included in the hole transport regions of the EL layers (103P, 103Q) and the charge generation layer 106R often have high conductivity, and therefore, if they are formed as layers common to adjacent light-emitting devices, they may cause crosstalk. Therefore, by providing the gap 580 as shown in this configuration example, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0225] In a high-resolution light-emitting device (display panel) exceeding 1000 ppi, if electrical conduction is found between EL layer 103B, EL layer 103G, and EL layer 103R, crosstalk occurs, narrowing the color gamut that can be displayed by the light-emitting device. By providing gap 580 in a high-resolution display panel exceeding 1000 ppi, preferably a high-resolution display panel exceeding 2000 ppi, and more preferably an ultra-high-resolution display panel exceeding 5000 ppi, it is possible to provide a display panel that can display vivid colors.

[0226] In this configuration example, the light-emitting device 550B, the light-emitting device 550G, and the light-emitting device 550R all emit white light. Therefore, the second substrate 770 has colored layers CFB, CFG, and CFR. These colored layers may be partially overlapped as shown in FIG. 9A. By partially overlapping the layers, the overlapped portions can function as a light-shielding film. In this configuration example, for example, the colored layer CFB is made of a material that preferentially transmits blue light (B), the colored layer CFG is made of a material that preferentially transmits green light (G), and the colored layer CFR is made of a material that preferentially transmits red light (R).

[0227] 9B shows the configuration of light-emitting device 550B, where light-emitting device 550B, light-emitting device 550G, and light-emitting device 550R are light-emitting devices that emit white light. EL layer 103P and EL layer 103Q are stacked on electrode 551B with charge generation layer 106B sandwiched therebetween. EL layer 103P includes light-emitting layer 113B, which emits blue light EL(1), as light-emitting layer 113P, and EL layer 103Q includes light-emitting layer 113G, which emits green light EL(2), and light-emitting layer 113R, which emits red light EL(3), as light-emitting layer 113Q.

[0228] Instead of the colored layer, a color conversion layer can be used, for example, nanoparticles, quantum dots, or the like can be used for the color conversion layer.

[0229] For example, the coloring layer CFG can be replaced with a color conversion layer that converts blue light into green light. This allows the white light emitted by the light-emitting device 550G to be converted into green light. Also, the coloring layer CFR can be replaced with a color conversion layer that converts blue light into red light. This allows the white light emitted by the light-emitting device 550R to be converted into red light.

[0230] <Configuration Example 4 of Light-Emitting Device 700> 10A includes light-emitting device 550B, light-emitting device 550G, light-emitting device 550R, and partition wall 528. Light-emitting device 550B, light-emitting device 550G, light-emitting device 550R, and partition wall 528 are formed on functional layer 520 provided on first substrate 510. Functional layer 520 includes drive circuits GD and SD, each of which is composed of a plurality of transistors, as well as wiring and the like that electrically connects these components. These drive circuits are electrically connected to light-emitting device 550B, light-emitting device 550G, and light-emitting device 550R and can drive them.

[0231] Light-emitting device 550B, light-emitting device 550G, and light-emitting device 550R have the device structure shown in Embodiment 1. This device structure is particularly suitable for the case where each light-emitting device has in common the EL layers (103P, 103Q) having the structure shown in FIG. 2B, a so-called tandem structure.

[0232] The specific configuration of each light emitting device shown in FIG. 10 is the same as that of light emitting device 550B, light emitting device 550G, and light emitting device 550R described in FIG. 9, and all of them emit white light.

[0233] Note that the light-emitting device shown in this configuration example differs from the configuration of the light-emitting device shown in Figure 9 in that it has colored layers CFB, CFG, and CFR formed on each light-emitting device formed on the first substrate 510.

[0234] That is, a first insulating layer 573 is provided on the electrode 552 of each light-emitting device formed on the first substrate 510, and color layers CFB, CFG, and CFR are provided on the first insulating layer 573.

[0235] Furthermore, a second insulating layer 705 is provided on the colored layers CFB, CFG, and CFR. The second insulating layer 705 has an area sandwiched between the second substrate 770 and the first substrate 510 on the colored layer (CFB, CFG, CFR) side, which includes the functional layer 520, the light-emitting devices (550B, 550G, 550R), and the colored layers CFB, CFG, and CFR, and has a function of bonding the first substrate 510 and the second substrate 770 together.

[0236] Note that the first insulating layer 573 and the second insulating layer 705 can be formed using an inorganic material, an organic material, a composite material of an inorganic material and an organic material, or the like.

[0237] The inorganic material may be an inorganic oxide film, an inorganic nitride film, an inorganic oxynitride film, or a laminate structure of a plurality of layers selected from these. For example, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, an aluminum oxide film, or a film including a laminate structure of a plurality of layers selected from these may be used. Note that a silicon nitride film is a dense film and has an excellent function of suppressing the diffusion of impurities. Alternatively, an oxide semiconductor (e.g., an IGZO film) may be used, for example, a laminate structure of an aluminum oxide film and an IGZO film on the aluminum oxide film.

[0238] The organic material may be polyester, polyolefin, polyamide, polyimide, polycarbonate, polysiloxane, acrylic, or a laminate or composite material of multiple resins selected from these. Alternatively, organic materials such as a reaction-curing adhesive, a photo-curing adhesive, a thermosetting adhesive, and / or an anaerobic adhesive may be used.

[0239] <Example 2 of manufacturing method of light emitting device> Next, a method for manufacturing the light emitting device shown in FIG. 10 will be described with reference to FIGS.

[0240] As shown in FIG. 11A, on the electrodes (551B, 551G, 551R) and the partition wall 528 (see FIG. 4B) formed on the first substrate 510, the EL layer 103P (including the light-emitting layer 113P and the hole injection / transport layer 104P), the charge generation layer 106, and the EL layer 103Q (including the light-emitting layer 113Q, the hole injection / transport layer 104Q, and the oxidation-resistant layer 105Q) are formed so as to cover them.

[0241] The oxidation-resistant layer 105Q included in the EL layer 103Q is formed using an oxidation-resistant material. Specifically, a composite material in which an electron acceptor material is added to a hole-transporting material, which is an organic compound, as exemplified in Embodiment 1 as a material that can be used for the charge generation layer of the EL layer, or a stack of a hole-transporting material and an electron acceptor material can be used. Furthermore, the materials exemplified in Embodiment 1 as organic acceptor materials used for the hole-injection layer can be used as the electron acceptor material. The use of a metal oxide as the electron acceptor material can improve oxidation resistance.

[0242] Examples of metal oxides include oxides of metals belonging to Groups 4 to 8 of the periodic table. Specific examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide. Furthermore, materials listed as hole-transporting materials can be used as organic compounds.

[0243] By adjusting the composition of the metal oxide and organic compound contained in oxidation-resistant layer 105Q to a predetermined value, it is possible to prevent oxidation-resistant layer 105Q from dissolving when a resist is formed on oxidation-resistant layer 105Q in a subsequent process. Regarding the composition of the metal oxide and organic compound used in oxidation-resistant layer 105Q, taking into consideration the film thickness and transmittance of oxidation-resistant layer 105Q, it is preferable that the weight of the organic compound be 1 / 100 to 100 times, and more preferably 1 / 20 to 20 times, the weight of the metal oxide.

[0244] Next, as shown in FIG. 11B, the EL layer 103P (including the light-emitting layer 113P and the hole injection / transport layer 104P), the charge generation layer 106, and the EL layer 103Q (including the light-emitting layer 113Q, the hole injection / transport layer 104Q, and the oxidation-resistant layer 105Q) on the electrodes (551B, 551G, 551R) are processed into a predetermined shape. For example, photolithography is used to form a resist REG on the EL layer 103Q (including the light-emitting layer 113Q, the hole injection / transport layer 104Q, and the oxidation-resistant layer 105Q) on the electrodes (551G, 551B, and 551R). Then, etching is performed to remove the EL layer 103P (including the light-emitting layer 113P and the hole injection / transport layer 104P), the charge generation layer 106, and the EL layer 103Q (including the light-emitting layer 113Q, the hole injection / transport layer 104Q, and the oxidation-resistant layer 105Q) on which the resist REG is not formed. This results in a shape with exposed sides or a strip-like shape extending in a direction transverse to the paper. Specifically, dry etching is performed using the resist REG formed on the EL layer 103Q (including the light-emitting layer 113Q, the hole injection / transport layer 104Q, and the oxidation-resistant layer 105Q) (see FIG. 11C). The partition wall 528 can be used as an etching stopper.

[0245] As a result, the EL layer 103P (including the light-emitting layer 113P and the hole injection / transport layer 104P), the charge generation layers (106B, 106G, 106R), and the EL layer 103Q (including the light-emitting layer 113Q, the hole injection / transport layer 104Q, and the oxidation-resistant layer 105Q) of the light-emitting devices 550B, 550G, and 550R can be formed separately by a single pattern formation using photolithography.

[0246] 12A , the blocking layer 107 and the electrode 552 are formed on the EL layer 103P (including the light-emitting layer 113P and the hole injection / transport layer 104P), the charge generation layers (106B, 106G, 106R), the EL layer 103Q (including the light-emitting layer 113Q, the hole injection / transport layer 104Q, and the oxidation-resistant layer 105Q), and the partition wall 528. For example, the blocking layer 107 and the electrode 552 are formed by vacuum deposition.

[0247] As a material used for the blocking layer 107, the hole transporting material described in Embodiment 1 can be used.

[0248] The blocking layer 107 is also formed on the side surfaces exposed when the EL layer 103P (including the light-emitting layer 113P and the hole injection / transport layer 104P), the charge generation layers (106B, 106G, 106R), and the EL layer 103Q (including the light-emitting layer 113Q, the hole injection / transport layer 104Q, and the oxidation-resistant layer 105Q) are etched.

[0249] The electrode 552 is formed on the blocking layer 107. The electrode 552 is configured to be in contact with the side surfaces of the EL layer 103P (including the light-emitting layer 113P and the hole injection / transport layer 104P), the charge generation layers (106B, 106G, 106R), and the EL layer 103Q (including the light-emitting layer 113Q, the hole injection / transport layer 104Q, and the oxidation-resistant layer 105Q) via the blocking layer 107. This prevents electrical short-circuiting between the EL layer 103P and the electrode 552, more specifically, between the hole injection / transport layer 104P and the electrode 552 in the EL layer 103P, or between the EL layer 103Q and the electrode 552, more specifically, between the hole injection / transport layer 104Q and the electrode 552 in the EL layer 103Q, or between the charge generation layers (106B, 106G, 106R) and the electrode 552.

[0250] When the EL layers (103P, 103Q) and charge generating layers 106 of each light-emitting device are processed separately for each light-emitting device, patterning is performed by photolithography, which allows the production of a high-definition light-emitting device (display panel). Furthermore, the edges of the EL layer (the side surfaces of the laminated structure constituting the EL layer) processed by patterning by photolithography have a shape that has approximately the same surface (or is located on approximately the same plane).

[0251] In addition, the hole injection layer and charge generation layer (106B, 106G, 106R) included in the hole transport region of the EL layer (103P, 103Q) often have high conductivity, and therefore, if they are formed as a layer common to adjacent light-emitting devices, they may cause crosstalk. Therefore, by separating the EL layer through pattern formation by photolithography as shown in this configuration example, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0252] The specific configuration of each light emitting device shown in FIG. 12(B) is the same as that of light emitting device 550B, light emitting device 550G, and light emitting device 550R described in FIG. 12(A).

[0253] Note that the light-emitting device shown in this configuration example differs from the configuration of the light-emitting device shown in Figure 12(A) in that it has colored layers CFB, CFG, and CFR formed on each light-emitting device formed on the first substrate 510.

[0254] That is, a first insulating layer 573 is provided on the electrode 552 of each light-emitting device formed on the first substrate 510, and color layers CFB, CFG, and CFR are provided on the first insulating layer 573.

[0255] Furthermore, a second insulating layer 705 is provided on the colored layers CFB, CFG, and CFR. The second insulating layer 705 is provided on the colored layer (CFB, CFG, CFR) side of the first substrate 510, which has the functional layer 520, each light-emitting device (550B, 550G, 550R), and the colored layers CFB, CFG, and CFR. Note that the first substrate 510 may have an area sandwiched between it and the second substrate, and may have a function of bonding the first substrate 510 and the second substrate together.

[0256] <Configuration Example 5 of Light-Emitting Device 700> 13A includes light-emitting device 550B, light-emitting device 550G, light-emitting device 550R, and partition wall 528. Light-emitting device 550B, light-emitting device 550G, light-emitting device 550R, and partition wall 528 are formed on functional layer 520 provided on first substrate 510. Functional layer 520 includes drive circuits GD and SD, each of which is composed of a plurality of transistors, as well as wiring and the like that electrically connects these components. These drive circuits are electrically connected to light-emitting device 550B, light-emitting device 550G, and light-emitting device 550R and can drive them.

[0257] Light-emitting device 550B, light-emitting device 550G, and light-emitting device 550R have the device structure described in embodiment 1. This device structure is particularly suitable for the case where each light-emitting device has in common EL layer 103 having the structure shown in FIG. 2B, a so-called tandem structure.

[0258] 13, there is a gap 580 between each light emitting device, for example, between light emitting device 550B and light emitting device 550G. Therefore, an insulating layer 540 is formed in this gap 580.

[0259] For example, EL layer 103P (including light-emitting layer 113P and hole injection / transport layer 104P), charge generation layers (106B, 106G, 106R), and EL layer 103Q (including light-emitting layer 113Q, hole injection / transport layer 104Q, and oxidation-resistant layer 105Q) can be separately formed by pattern formation using photolithography, and then insulating layer 540 can be formed in gap 580 on partition wall 528 using photolithography. Furthermore, electrode 552 can be formed on EL layer 103Q (including light-emitting layer 113Q, hole injection / transport layer 104Q, and oxidation-resistant layer 105Q) and insulating layer 540.

[0260] In this configuration, the EL layers are separated by the insulating layer 540, so the block layer (107 in FIG. 9) shown in Configuration Example 3 is not necessary.

[0261] When the EL layers (103P, 103Q) and charge generating layers 106 of each light-emitting device are processed separately for each light-emitting device, patterning is performed by photolithography, which allows the production of a high-definition light-emitting device (display panel). Furthermore, the edges of the EL layer (the side surfaces of the laminated structure constituting the EL layer) processed by patterning by photolithography have a shape that has approximately the same surface (or is located on approximately the same plane).

[0262] In addition, the hole injection layer and charge generation layer (106B, 106G, 106R) included in the hole transport region of the EL layer (103P, 103Q) often have high conductivity, and therefore, if they are formed as a layer common to adjacent light-emitting devices, they may cause crosstalk. Therefore, by separating the EL layer through pattern formation by photolithography as shown in this configuration example, it is possible to suppress the occurrence of crosstalk between adjacent light-emitting devices.

[0263] (Embodiment 3) In this embodiment, a light-emitting device according to one embodiment of the present invention will be described with reference to FIGS. 14 to 16. Note that a light-emitting device 700 shown in FIGS. 14 to 16 includes the light-emitting device described in Embodiment 1. The light-emitting device 700 described in this embodiment can be applied to a display portion of an electronic device or the like, and therefore can also be called a display panel.

[0264] 14A, light-emitting device 700 described in this embodiment includes display region 231, which has pixel 703(i,j). Also, as shown in FIG. 14B, light-emitting device 700 includes pixel 703(i+1,j) adjacent to pixel 703(i,j).

[0265] It should be noted that multiple pixels can be used for pixel 703(i,j). For example, multiple pixels that display colors with different hues can be used. Each of the multiple pixels can be referred to as a sub-pixel. Alternatively, a set of multiple sub-pixels can be referred to as a pixel.

[0266] This allows the colors displayed by the plurality of pixels to be mixed by additive or subtractive color mixing, or allows colors of hues that cannot be displayed by individual pixels to be displayed.

[0267] Specifically, pixel 702B(i,j) that displays blue, pixel 702G(i,j) that displays green, and pixel 702R(i,j) that displays red can be used as pixel 703(i,j). Furthermore, each of pixel 702B(i,j), pixel 702G(i,j), and pixel 702R(i,j) can be referred to as a sub-pixel.

[0268] Furthermore, a pixel that displays white or the like may be used as pixel 703(i,j) in addition to the above set. Also, a pixel that displays cyan, a pixel that displays magenta, and a pixel that displays yellow may be used as pixel 703(i,j).

[0269] In addition to the above pair, a pixel that emits infrared light may be used as pixel 703(i,j). Specifically, a pixel that emits light including light having a wavelength of 650 nm or more and 1000 nm or less may be used as pixel 703(i,j).

[0270] 14A, a driving circuit GD and a driving circuit SD are provided around the display area 231. Terminals 519 are also provided which are electrically connected to the driving circuits GD and SD. The terminals 519 can be electrically connected to, for example, a flexible printed circuit FPC1 (see FIG. 16).

[0271] The driver circuit GD has the function of supplying a first selection signal and a second selection signal. For example, the driver circuit GD is electrically connected to the conductive film G1(i) and supplies a first selection signal, and is electrically connected to the conductive film G2(i) and supplies a second selection signal. The driver circuit SD has the function of supplying an image signal and a control signal, and the control signal includes a first level and a second level. For example, the driver circuit SD is electrically connected to the conductive film S1g(j) and supplies an image signal, and is electrically connected to the conductive film S2g(j) and supplies a control signal.

[0272] 16A, the light-emitting device 700 has a functional layer 520 between the first substrate 510 and the second substrate 770. The functional layer 520 includes the above-mentioned drive circuit GD, drive circuit SD, and the like, as well as wiring and the like that electrically connects these together. In FIG. 16A, the functional layer 520 is shown to have a configuration including pixel circuits 530B(i,j) and 530G(i,j) and drive circuit GD, but is not limited to this.

[0273] Furthermore, each pixel circuit (e.g., pixel circuit 530B(i,j) and pixel circuit 530G(i,j) shown in FIG. 16A) included in functional layer 520 is electrically connected to each light-emitting device (e.g., light-emitting device 550B(i,j) and light-emitting device 550G(i,j) shown in FIG. 16A) formed on functional layer 520. Furthermore, a second insulating layer 705 is provided on functional layer 520 and each light-emitting device, and second insulating layer 705 has the function of bonding second substrate 770 and functional layer 520 together.

[0274] Note that a substrate provided with touch sensors arranged in a matrix can be used as the second substrate 770. For example, a substrate provided with a capacitive touch sensor or an optical touch sensor can be used as the second substrate 770. In this way, the light-emitting device of one embodiment of the present invention can be used as a touch panel.

[0275] FIG. 15A shows a specific configuration of pixel circuit 530G(i,j).

[0276] 15A, pixel circuit 530G(i,j) includes a switch SW21, a switch SW22, a transistor M21, a capacitor C21, and a node N21. Pixel circuit 530G(i,j) also includes a node N22, a capacitor C22, and a switch SW23.

[0277] The transistor M21 has a gate electrode electrically connected to the node N21, a first electrode electrically connected to the light-emitting device 550G(i,j), and a second electrode electrically connected to the conductive film ANO.

[0278] The switch SW21 has a first terminal electrically connected to the node N21 and a second terminal electrically connected to the conductive film S1g(j), and has the function of controlling the conductive state or non-conductive state based on the potential of the conductive film G1(i).

[0279] The switch SW22 has a first terminal electrically connected to the conductive film S2g(j), and has a function of controlling the conductive state or non-conductive state based on the potential of the conductive film G2(i).

[0280] The capacitor C21 has a conductive film electrically connected to the node N21 and a conductive film electrically connected to the second electrode of the switch SW22.

[0281] This allows an image signal to be stored in node N21. Alternatively, the potential of node N21 can be changed using switch SW22. Alternatively, the intensity of light emitted by light-emitting device 550G(i,j) can be controlled using the potential of node N21.

[0282] 15B shows an example of a specific structure of the transistor M21 described with reference to Fig. 15A. Note that a bottom-gate transistor, a top-gate transistor, or the like can be used as the transistor M21 as appropriate.

[0283] 15B includes a semiconductor film 508, a conductive film 504, a conductive film 512A, and a conductive film 512B. The transistor is formed over, for example, an insulating film 501C.

[0284] The semiconductor film 508 has a region 508A electrically connected to the conductive film 512A and a region 508B electrically connected to the conductive film 512B. The semiconductor film 508 has a region 508C between the region 508A and the region 508B.

[0285] The conductive film 504 has a region overlapping with the region 508C, and functions as a gate electrode.

[0286] The insulating film 506 has a region sandwiched between the semiconductor film 508 and the conductive film 504. The insulating film 506 functions as a gate insulating film.

[0287] The conductive film 512A has either a function as a source electrode or a function as a drain electrode, and the conductive film 512B has the other function as a source electrode or a drain electrode.

[0288] The conductive film 524 can also be used for a transistor. The conductive film 524 has a region where the semiconductor film 508 is sandwiched between the conductive film 524 and the conductive film 504. The conductive film 524 functions as a second gate electrode. The insulating film 501D is sandwiched between the semiconductor film 508 and the conductive film 524 and functions as a second gate insulating film.

[0289] Note that a semiconductor film to be used for a transistor in a pixel circuit can be formed in the same process as a semiconductor film to be used for a transistor in a driver circuit. For example, a semiconductor film having the same composition as that of a semiconductor film to be used for a transistor in a pixel circuit can be used for the driver circuit.

[0290] A semiconductor containing an element of Group 14 can be used for the semiconductor film 508. Specifically, a semiconductor containing silicon can be used for the semiconductor film 508.

[0291] Furthermore, hydrogenated amorphous silicon can be used for the semiconductor film 508. Alternatively, microcrystalline silicon or the like can be used for the semiconductor film 508. This makes it possible to provide a light-emitting device with less display unevenness than, for example, a light-emitting device (or display panel) using polysilicon for the semiconductor film 508. Alternatively, it is easy to increase the size of the light-emitting device.

[0292] Furthermore, polysilicon can be used for the semiconductor film 508. This allows the field-effect mobility of the transistor to be higher than that of a transistor using hydrogenated amorphous silicon for the semiconductor film 508, for example. Also, the driving capability can be improved compared to that of a transistor using hydrogenated amorphous silicon for the semiconductor film 508, for example. Alternatively, the aperture ratio of a pixel can be improved compared to that of a transistor using hydrogenated amorphous silicon for the semiconductor film 508, for example.

[0293] Alternatively, the reliability of the transistor can be improved compared to a transistor using hydrogenated amorphous silicon for the semiconductor film 508, for example.

[0294] Alternatively, the temperature required to manufacture the transistor can be lower than that of a transistor using single crystal silicon, for example.

[0295] Alternatively, a semiconductor film used for a transistor in a driver circuit can be formed in the same process as a semiconductor film used for a transistor in a pixel circuit. Alternatively, the driver circuit can be formed over the same substrate as the substrate on which the pixel circuit is formed. Alternatively, the number of components constituting an electronic device can be reduced.

[0296] Furthermore, single crystal silicon can be used for the semiconductor film 508. This allows for higher definition than, for example, a light-emitting device (or display panel) using hydrogenated amorphous silicon for the semiconductor film 508. Alternatively, for example, a light-emitting device with less display unevenness can be provided than, for example, a light-emitting device using polysilicon for the semiconductor film 508. Alternatively, for example, smart glasses or a head-mounted display can be provided.

[0297] Furthermore, metal oxide can be used for the semiconductor film 508. This allows the pixel circuit to retain an image signal for a longer period of time compared to a pixel circuit that uses a transistor with hydrogenated amorphous silicon as the semiconductor film. Specifically, the selection signal can be supplied at a frequency of less than 30 Hz, preferably less than 1 Hz, and more preferably less than once per minute, while suppressing the occurrence of flicker. As a result, fatigue accumulated in the user of the electronic device can be reduced. Furthermore, power consumption associated with driving can be reduced.

[0298] An oxide semiconductor can be used for the semiconductor film 508. Specifically, an oxide semiconductor containing indium, an oxide semiconductor containing indium, gallium, and zinc, or an oxide semiconductor containing indium, gallium, zinc, and tin can be used for the semiconductor film 508.

[0299] Note that by using an oxide semiconductor for the semiconductor film, a transistor having a smaller leakage current in an off state than a transistor using hydrogenated amorphous silicon for the semiconductor film can be obtained. Therefore, it is preferable to use a transistor using an oxide semiconductor for the semiconductor film as a switch or the like. Note that a circuit using a transistor using an oxide semiconductor for the semiconductor film as a switch can hold the potential of a floating node for a longer time than a circuit using a transistor using hydrogenated amorphous silicon for the semiconductor film as a switch.

[0300] 16A shows a light-emitting device having a structure (top emission type) in which light is extracted on the second substrate 770 side, but as shown in FIG. 16B, a light-emitting device having a structure (bottom emission type) in which light is extracted on the first substrate 510 side may also be used. In the case of a bottom emission type light-emitting device, the first electrode is formed to function as a semi-transmissive and semi-reflective electrode, and the second electrode is formed to function as a reflective electrode.

[0301] Although an active matrix light-emitting device has been described in FIGS. 16A and 16B, the structure of the light-emitting device shown in Embodiment 1 may be applied to a passive matrix light-emitting device shown in FIG.

[0302] FIG. 17A is a perspective view showing a passive matrix light-emitting device, and FIG. 17B is a cross-sectional view taken along the XY line in FIG. 17A. In FIG. 17, an EL layer 955 is provided between an electrode 952 and an electrode 956 on a substrate 951. An end of the electrode 952 is covered with an insulating layer 953. A partition layer 954 is provided on the insulating layer 953. The sidewalls of the partition layer 954 are inclined such that the distance between one sidewall and the other sidewall becomes narrower as the distance becomes closer to the substrate surface. In other words, the cross section of the partition layer 954 in the minor axis direction is trapezoidal, and the lower base (the side in contact with the insulating layer 953) is shorter than the upper base. In this way, providing the partition layer 954 can prevent defects in the light-emitting device caused by static electricity, etc.

[0303] Note that the structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0304] (Fourth embodiment) In this embodiment, the structure of an electronic device of one embodiment of the present invention will be described with reference to FIGS.

[0305] 18 to 20 illustrate the structure of an electronic device of one embodiment of the present invention. FIG. 18A is a block diagram of the electronic device, and FIGS. 18B to 18E are perspective views illustrating the structure of the electronic device. FIGS. 19A to 19E are perspective views illustrating the structure of the electronic device. FIGS. 20A and 20B are perspective views illustrating the structure of the electronic device.

[0306] An electronic device 5200B described in this embodiment includes an arithmetic device 5210 and an input / output device 5220 (see FIG. 18A).

[0307] The arithmetic unit 5210 has a function of receiving operation information and a function of supplying image information based on the operation information.

[0308] The input / output device 5220 has a display unit 5230, an input unit 5240, a detection unit 5250, a communication unit 5290, a function for supplying operation information, and a function for receiving image information. The input / output device 5220 also has a function for supplying detection information, a function for supplying communication information, and a function for receiving communication information.

[0309] The input unit 5240 has a function of supplying operation information. For example, the input unit 5240 supplies operation information based on an operation by the user of the electronic device 5200B.

[0310] Specifically, the input unit 5240 can use a keyboard, hardware buttons, a pointing device, a touch sensor, an illuminance sensor, an imaging device, a voice input device, a gaze input device, a posture detection device, or the like.

[0311] The display portion 5230 has a function of displaying a display panel and displaying image information. For example, the display panel described in Embodiment 2 can be used as the display portion 5230.

[0312] The detection unit 5250 has a function of supplying detection information, for example, a function of detecting the surrounding environment in which the electronic device is used and supplying the detected information.

[0313] Specifically, the detection unit 5250 can use an illuminance sensor, an imaging device, a posture detection device, a pressure sensor, a human sensor, or the like.

[0314] The communication unit 5290 has a function of receiving and supplying communication information. For example, it has a function of connecting to other electronic devices or communication networks by wireless communication or wired communication. Specifically, it has functions such as wireless local area communication, telephone communication, and short-range wireless communication.

[0315] FIG. 18B shows an electronic device having an outer shape that conforms to a cylindrical pillar or the like. One example is digital signage. The display panel according to one embodiment of the present invention can be applied to the display unit 5230. The display panel may have a function of changing the display method depending on the illuminance of the usage environment. It also has a function of detecting the presence of a person and changing the display content. This allows the display panel to be installed on a pillar of a building, for example. Alternatively, advertisements or information can be displayed. Alternatively, the display panel can be used for digital signage.

[0316] FIG. 18C shows an electronic device that has the function of generating image information based on the trajectory of a pointer used by a user. Examples include an electronic whiteboard, an electronic bulletin board, and an electronic signboard. Specifically, a display panel with a diagonal length of 20 inches or more, preferably 40 inches or more, and more preferably 55 inches or more can be used. Alternatively, multiple display panels can be arranged to form a single display area. Alternatively, multiple display panels can be arranged to form a multi-screen.

[0317] FIG. 18D shows an electronic device as a wristwatch-type mobile information terminal that can receive information from other devices and display it on the display unit 5230. One example is a smartwatch (registered trademark). Specifically, it can display several options, or the user can select several options and send a reply to the sender of the information. Alternatively, it can have a function to change the display method depending on the illuminance of the usage environment. This can reduce the power consumption of the smartwatch, for example. Alternatively, it can display images on the smartwatch so that it can be used effectively even in environments with strong external light, such as outdoors on a sunny day.

[0318] 18E shows an electronic device having a display unit 5230 with a curved surface that gently curves along the side of the housing. An example is a mobile phone. The display unit 5230 has a display panel, which has the function of displaying information on, for example, the front, side, top, and back of the mobile phone. This allows information to be displayed not only on the front of the mobile phone, but also on the side, top, and back.

[0319] FIG. 19A shows an electronic device that can receive information from the Internet and display it on the display unit 5230. An example of such an electronic device is a smartphone. For example, a created message can be checked on the display unit 5230. Alternatively, the created message can be sent to another device. Alternatively, the device has a function of changing the display method depending on the illuminance of the usage environment. This can reduce the power consumption of the smartphone. Alternatively, for example, an image can be displayed on the display unit 5230 so that the smartphone can be used suitably even in an environment with strong external light, such as outdoors on a sunny day.

[0320] FIG. 19B shows an electronic device that can use a remote controller as the input unit 5240. An example is a television system. Alternatively, information can be received from a broadcasting station or the Internet and displayed on the display unit 5230. Alternatively, a user can be photographed using the detection unit 5250. An image of the user can be transmitted. Alternatively, the user's viewing history can be acquired and provided to a cloud service. Alternatively, recommendation information can be acquired from a cloud service and displayed on the display unit 5230. Alternatively, programs or videos can be displayed based on the recommendation information. Alternatively, the electronic device can have a function to change the display method depending on the illuminance of the usage environment. This allows images to be displayed on the display unit 5230 so that it can be used appropriately even when strong external light shines indoors on a sunny day.

[0321] 19C shows an electronic device that can receive learning materials from the Internet and display them on the display unit 5230. An example is a tablet computer. Alternatively, a report can be entered using the input unit 5240 and sent to the Internet. Alternatively, corrections or evaluations of the report can be obtained from a cloud service and displayed on the display unit 5230. Alternatively, suitable learning materials can be selected and displayed based on the evaluations.

[0322] For example, an image signal can be received from another electronic device and displayed on the display unit 5230. Alternatively, the display unit 5230 can be used as a sub-display by placing the tablet computer on a stand or the like. This allows images to be displayed on the tablet computer so that the tablet computer can be used suitably even in an environment with strong external light, such as outdoors on a sunny day.

[0323] FIG. 19D shows an electronic device having multiple display units 5230. An example is a digital camera. For example, an image can be captured by the detection unit 5250 and displayed on the display unit 5230. Alternatively, the captured image can be displayed on the display unit 5230. Alternatively, the captured image can be decorated using the input unit 5240. Alternatively, a message can be attached to the captured image. Alternatively, the captured image can be sent to the Internet. Alternatively, the electronic device has a function to change the capture conditions depending on the illuminance of the usage environment. This allows the subject to be displayed on the display unit 5230 so that it can be viewed appropriately even in an environment with strong external light, such as outdoors on a sunny day.

[0324] FIG. 19E shows an electronic device that can control another electronic device using the electronic device of this embodiment as a master, with the other electronic device used as a slave. One example is a portable personal computer. For example, part of the image information can be displayed on the display unit 5230, and another part of the image information can be displayed on the display unit of the other electronic device. Alternatively, an image signal can be supplied. Alternatively, information to be written can be obtained from the input unit of the other electronic device using the communication unit 5290. This allows, for example, a portable personal computer to utilize a large display area.

[0325] FIG. 20A shows an electronic device having a detection unit 5250 that detects acceleration or orientation. An example is a goggle-type electronic device. Alternatively, the detection unit 5250 can provide information related to the user's position or the direction the user is facing. Alternatively, the electronic device can generate image information for the right eye and image information for the left eye based on the user's position or the direction the user is facing. Alternatively, the display unit 5230 has a display area for the right eye and a display area for the left eye. This allows, for example, an image of a virtual reality space that provides an immersive experience to be displayed on the display unit 5230.

[0326] FIG. 20B shows an electronic device having a detection unit 5250 that detects an imaging device, acceleration, or orientation. An example is a glasses-type electronic device. Alternatively, the detection unit 5250 can provide information related to the user's position or the direction the user is facing. Alternatively, the electronic device can generate image information based on the user's position or the direction the user is facing. This allows, for example, information to be attached to a real landscape and displayed. Alternatively, an image of an augmented reality space can be displayed on the glasses-type electronic device.

[0327] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0328] (Embodiment 5) In this embodiment, a structure in which the light-emitting device described in Embodiment 2 is used as a lighting device will be described with reference to Fig. 21. Fig. 21A is a cross-sectional view of the lighting device shown in Fig. 21B taken along line ef in a top view thereof.

[0329] In the lighting device of this embodiment, a first electrode 401 is formed over a light-transmitting substrate 400, which serves as a support. The first electrode 401 corresponds to the first electrode 101 in Embodiment 1. When light is extracted from the first electrode 401 side, the first electrode 401 is formed using a light-transmitting material.

[0330] A pad 412 for supplying a voltage to the second electrode 404 is formed on the substrate 400 .

[0331] An EL layer 403 is formed on the first electrode 401. The EL layer 403 corresponds to the structure of the EL layer 103 in Embodiment 1, or a combination of the EL layers 103a, 103b, and 103c and the charge generation layer 106 (106a and 106b). For details of these structures, see the description thereof.

[0332] A second electrode 404 is formed to cover the EL layer 403. The second electrode 404 corresponds to the second electrode 102 in Embodiment 1. When light is extracted from the first electrode 401 side, the second electrode 404 is formed of a material with high reflectivity. The second electrode 404 is connected to a pad 412 to supply a voltage.

[0333] As described above, the lighting device described in this embodiment has a light-emitting device including the first electrode 401, the EL layer 403, and the second electrode 404. Since the light-emitting device has high emission efficiency, the lighting device in this embodiment can be a lighting device with low power consumption.

[0334] The lighting device is completed by bonding and sealing substrate 407, on which the light-emitting device having the above configuration is formed, using sealants 405 and 406. Either sealant 405 or 406 can be used. Also, a desiccant can be mixed into inner sealant 406 (not shown in FIG. 21B), which can absorb moisture and improve reliability.

[0335] Furthermore, the pad 412 and a part of the first electrode 401 can be extended outside the sealing materials 405 and 406 to serve as an external input terminal. An IC chip 420 equipped with a converter or the like may also be provided thereon.

[0336] (Embodiment 6) In this embodiment, application examples of a lighting device manufactured using a light-emitting device which is one embodiment of the present invention or a light-emitting device which is a part of the light-emitting device will be described with reference to FIGS.

[0337] As an indoor lighting device, it can be applied as a ceiling light 8001. Ceiling lights 8001 are available in direct ceiling mount and recessed ceiling types. Such lighting devices are constructed by combining a light emitting device with a housing and a cover. It can also be applied to cord pendant types (hanging from the ceiling with a cord).

[0338] The foot lamp 8002 can also project light onto the floor, improving safety around the feet. For example, it is effective for use in bedrooms, stairs, and corridors. In this case, the size and shape can be changed appropriately depending on the size and structure of the room. It can also be used as a stationary lighting device consisting of a light-emitting device and a support base.

[0339] The sheet lighting 8003 is a thin sheet lighting device. It is attached to a wall surface and can be used for a wide range of purposes without taking up much space. It can also be easily made larger. It can also be used on curved walls and housings.

[0340] It is also possible to use a lighting device 8004 in which light from a light source is controlled to only a desired direction.

[0341] The desk lamp 8005 includes a light source 8006, and the light-emitting device according to one embodiment of the present invention or a light-emitting device that is a part of the light-emitting device can be used as the light source 8006.

[0342] In addition to the above, by applying the light-emitting device of one embodiment of the present invention or a light-emitting device that is a part of the light-emitting device to a part of furniture installed in a room, the lighting device can have the function of the furniture.

[0343] As described above, various lighting devices using the light-emitting device can be obtained. Note that these lighting devices are included in one embodiment of the present invention.

[0344] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments. [Explanation of symbols]

[0345] 100: light-emitting device, 101: first electrode, 102: second electrode, 103, 103a, 103b, 103c: EL layer, 103B, 103G, 103R: EL layer, 103P, 103Q: EL layer, 104, 104a, 104b: hole injection and transport layer, 104B, 104G, 104R: hole injection and transport layer, 104P, 104Q: hole injection and transport layer, 105, 105B, 105G, 105R: oxidation-resistant layer, 106, 106B, 106G, 106R: charge generation layer, 107: blocking layer, 108: electron injection and transport layer, 111, 111a, 111b: hole injection layer, 112, 112a, 112b: hole transport layer, 113, 113a, 113b, 113c: light emitting layer, 114, 114b: electron transport layer, 115, 115b: electron injection layer, 231: display region, 400: substrate, 401: first electrode, 403: EL layer, 404: second electrode, 405, 406: sealing material, 407: sealing substrate, 412: pad, 420: IC chip, 501C: insulating film, 501D: insulating film, 504: conductive film, 506: insulating film, 508: semiconductor film, 508A: region, 508B: region, 508C: region, 510: substrate, 512A: conductive film, 512B: conductive film, 519: terminal, 520: functional layer, 524: conductive film, 528: partition wall, 528B: opening, 528G: opening, 528R: opening, 530B: pixel circuit, 530G: pixel circuit, 540: insulating layer, 550B: light-emitting device, 550G: light-emitting device, 550R: light-emitting device, 551B: electrode, 551G: electrode, 551R: electrode, 552: electrode, 573: insulating layer, 580: gap, 700: light-emitting device , 702B: pixel, 702G: pixel, 702R: pixel, 703: pixel, 705: insulating layer, 770: substrate, 951: substrate, 952: electrode, 953: insulating layer, 954: partition layer, 955: EL layer, 956: electrode, 5200B: electronic device, 5210: computing unit, 5220: input / output device, 5230: display unit, 5240: input unit, 5250: detection unit, 5290: communication unit, 8001: ceiling light, 8002: foot light, 8003: sheet-type lighting, 8004: lighting device, 8005: desk lamp, 8006: light source

Claims

1. a first light-emitting device, a second light-emitting device, a partition wall, and an insulating layer; the first light-emitting device comprises a first electrode, a first hole injection layer, a first hole transport layer, a first light-emitting layer, a first electron transport layer, a first electron injection layer, a first oxidation-resistant layer, and a second electrode; the first hole injection layer is located between the first electrode and the first hole transport layer; the first hole transport layer is located between the first hole injection layer and the first light-emitting layer; the first light-emitting layer is located between the first hole transport layer and the first electron transport layer; the first electron transport layer is located between the first light-emitting layer and the first electron injection layer; the first electron injection layer is located between the first electron transport layer and the first oxidation-resistant layer; the first oxidation-resistant layer is located between the first electron injection layer and the second electrode; the second light-emitting device comprises a third electrode, a second hole injection layer, a second hole transport layer, a second light-emitting layer, a second electron transport layer, a second electron injection layer, a second oxidation-resistant layer, and the second electrode; the second hole injection layer is located between the third electrode and the second hole transport layer; the second hole transport layer is located between the second hole injection layer and the second light-emitting layer; the second light-emitting layer is located between the second hole transport layer and the second electron transport layer; the second electron transport layer is located between the second light-emitting layer and the second electron injection layer; the second electron injection layer is located between the second electron transport layer and the second oxidation-resistant layer; the second oxidation-resistant layer is located between the second electron injection layer and the second electrode; the partition wall covers an end of the first electrode and an end of the third electrode; the insulating layer is provided in contact with an upper surface of the partition wall, a side surface of the first hole injection layer, a side surface of the first hole transport layer, a side surface of the first light-emitting layer, a side surface of the first electron transport layer, a side surface of the first electron injection layer, a side surface of the first oxidation-resistant layer, a side surface of the second hole injection layer, a side surface of the second hole transport layer, a side surface of the second light-emitting layer, a side surface of the second electron transport layer, a side surface of the second electron injection layer, and a side surface of the second oxidation-resistant layer; the second electrode is provided in contact with an upper surface of the first oxidation-resistant layer, an upper surface of the second oxidation-resistant layer, and an upper surface of the insulating layer.

2. In claim 1, a light-emitting device, wherein the first oxidation-resistant layer and the second oxidation-resistant layer contain one or more selected from oxides of metals belonging to groups 4 to 8 of the periodic table and organic compounds having electron-withdrawing groups;

3. In claim 1 or claim 2, The first oxidation-resistant layer and the second oxidation-resistant layer may be formed of any of molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, rhenium oxide, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane, 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane, chloranil, 2,3,6, A light-emitting device comprising one or more selected from 7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane, and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile.

4. A light emitting device according to any one of claims 1 to 3; An electronic device having at least one of a sensor, an operation button, a speaker, and a microphone.

5. A lighting device comprising: the light-emitting device according to claim 1; and a housing.

Images