WO2014020850A1

WO2014020850A1 - Light emitting device, display unit including the same, and electronic apparatus

Info

Publication number: WO2014020850A1
Application number: PCT/JP2013/004400
Authority: WO
Inventors: Kenichi Izumi; Kohji Hanawa; Jiro Yamada
Original assignee: Sony Corporation
Priority date: 2012-07-30
Filing date: 2013-07-18
Publication date: 2014-02-06
Also published as: KR20150040249A; TW201405909A; JP2014027192A; CN104335380A

Abstract

A light emitting device includes: a first electrode (21); an organic layer (23) including a light emission layer; a resistance layer (50) including zinc oxide; and a second electrode (22), the first electrode, the organic layer, the resistance layer and the second electrode being provided in this order, in which a crystal orientation of the zinc oxide includes a plurality of plane index components.

Description

LIGHT EMITTING DEVICE, DISPLAY UNIT INCLUDING THE SAME, AND ELECTRONIC APPARATUS

The present technology relates to a light emitting device having a resistance layer together with an organic layer between two electrodes, to a display unit including the same, and to an electronic apparatus.

An organic EL (Electroluminescence) device is applied to a display unit as a device capable of high-brightness light emission by low-voltage direct current drive. Such an organic EL device may have, for example, a first electrode, an organic layer including a light emission layer, and a second electrode in this order. In order to control emitted light thereof, introduction of a resonator structure has been proposed (for example, PTL 1).

In the case where each thickness of each layer configuring the organic layer is optimized by the resonator structure, color purity of emission color and light emission efficiency are improved. However, when the thickness of the organic layer is decreased, short-circuit may occur between the first electrode and the second electrode. In order to prevent such short-circuit, in PTL 2 to PTL6, methods of interposing a film with a high resistance in an organic EL device are disclosed.

WO01/39554 Japanese Unexamined Patent Application Publication No. 2001-035667 Japanese Unexamined Patent Application Publication No. 2006-338916 Japanese Unexamined Patent Application Publication No. 2005-209647 Japanese Unexamined Patent Application Publication No. 2011-103205 Japanese Unexamined Patent Application Publication No. 2011-040244

Summary

However, even with the use of the foregoing methods, occurrence of a defective device due to short-circuit has not been sufficiently prevented yet. Therefore, it has been desired to prevent short-circuit between the first electrode and the second electrode more securely.

It is desirable to provide a light emitting device capable of preventing short-circuit between a first electrode and a second electrode more securely, a display unit including the same, and an electronic apparatus.

According to an embodiment of the present technology, there is provided a light emitting device including: a first electrode; an organic layer including a light emission layer; a resistance layer including zinc oxide; and a second electrode, the first electrode, the organic layer, the resistance layer and the second electrode being provided in this order, in which a crystal orientation of the zinc oxide includes a plurality of plane index components.

According to an embodiment of the present technology, there is provided a display unit provided with a plurality of light emitting devices, each of the light emitting devices, including: a first electrode; an organic layer including a light emission layer; a resistance layer including zinc oxide; and a second electrode, the first electrode, the organic layer, the resistance layer and the second electrode being provided in this order, in which a crystal orientation of the zinc oxide includes a plurality of plane index components.

According to an embodiment of the present technology, there is provided an electronic apparatus provided with a display unit, the display unit being provide with a plurality of light emitting devices, each of the light emitting devices, including: a first electrode; an organic layer including a light emission layer; a resistance layer including zinc oxide; and a second electrode, the first electrode, the organic layer, the resistance layer and the second electrode being provided in this order, in which a crystal orientation of the zinc oxide includes a plurality of plane index components.

In the light emitting device according to the embodiment of the present technology, even if a region where the organic layer is not formed between the first electrode and the second electrode is created due to, for example, adhesion of a foreign matter or the like, the resistance layer containing zinc oxide is interposed between the electrodes. Since the crystal orientation of zinc oxide includes the plurality of plane indices components, film stress is reduced, and zinc oxide is allowed to be contained in the resistance layer. Zinc oxide has optical characteristics close to those of the organic layer, compared to other high resistance material.

According to the light emitting device, the display unit, and the electronic apparatus according to the embodiments of the present technology, the resistance layer containing zinc oxide is provided between the organic layer and the second electrode. Therefore, short-circuit between the first electrode and the second electrode is allowed to be more securely prevented. Further, light extraction efficiency is also allowed to be improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the technology as claimed.

Fig. 1 is a cross-sectional view illustrating a configuration of a display unit according to an embodiment of the present technology. Fig. 2 is a diagram illustrating a whole configuration of the display unit illustrated in Fig. 1. Fig. 3 is a diagram illustrating an example of a pixel drive circuit illustrated in Fig. 2. Fig. 4A is a cross-sectional view for explaining a configuration of an organic layer illustrated in Fig. 1. Fig. 4B is a cross-sectional view illustrating another example of the organic layer illustrated in Fig. 4A. Fig. 5 is a plan view illustrating a configuration of a semi-transmissive reflecting film illustrated in Fig. 1. Fig. 6A is a cross-sectional view illustrating a method of manufacturing the display unit illustrated in Fig. 1. Fig. 6B is a cross-sectional view illustrating a step following a step of Fig. 6A. Fig. 6C is a cross-sectional view illustrating a step following the step of Fig. 6B. Fig. 7A is a cross-sectional view illustrating a step following the step of Fig. 6C. Fig. 7B is a cross-sectional view illustrating a step following the step of Fig. 7A. Fig. 8A is a cross-sectional view illustrating a step following the step of Fig. 7B. Fig. 8B is a cross-sectional view illustrating a step following the step of Fig. 8A. Fig. 9 is a cross-sectional view for explaining a case that a foreign matter exists on a first electrode illustrated in Fig. 1. Fig. 10 is a diagram illustrating a result of an X-ray analysis of a resistance layer illustrated in Fig. 1. Fig. 11 is a diagram illustrating a relation between a ratio of (101) component in a crystal orientation of zinc oxide and stress size. Fig. 12 is a cross-sectional view illustrating a configuration of a display unit according to Modification 1. Fig. 13 is a cross-sectional view illustrating a configuration of a display unit according to Modification 2. Fig. 14 is a cross-sectional view illustrating a configuration of a display unit according to Modification 3. Fig. 15 is a plan view illustrating a configuration of an extraction electrode illustrated in Fig. 14. Fig. 16 is a cross-sectional view illustrating another example of the extraction electrode illustrated in Fig. 14. Fig. 17 is a plan view illustrating a schematic configuration of a module including the display unit illustrated in Fig. 1 and the like. Fig. 18 is a perspective view illustrating an appearance of Application example 1. Fig. 19A is a perspective view illustrating an appearance viewed from the front side of Application example 2. Fig. 19B is a perspective view illustrating an appearance viewed from the rear side of Application example 2. Fig. 20 is a perspective view illustrating an appearance of Application example 3. Fig. 21 is a perspective view illustrating an appearance of Application example 4. Fig. 22A is a diagram illustrating Application example 5 in a closed state. Fig. 22B is a diagram illustrating Application example 5 in an open state. Fig. 23 is a perspective view illustrating an appearance of Application example 6.

A preferred embodiment of the present technology will be described in detail below with reference to the drawings. The description will be given in the following order.
1. Embodiment (a display unit: an example in which a resistance layer includes zinc oxide)
2. Modification 1 (an example in which a conductive resin layer is included between a resistance layer and a second electrode)
3. Modification 2 (an example in which an auxiliary electrode is included)
4. Modification 3 (an example in which an extraction electrode is included)

(Embodiment)
(Whole Configuration of Display Unit 1)
Fig. 1 illustrates a cross-sectional configuration of a main section of a display unit (display unit 1) according to an embodiment of the present technology. The display unit 1 is a self-luminous type display unit including a plurality of organic EL devices 20, and has a pixel drive circuit formation layer L1, a light emitting device formation layer L2 including the organic EL devices 20, and an opposed substrate 33 in this order on a support substrate 11. The display unit 1 is a so-called top-emission type display unit having a light extraction direction on the opposed substrate 33 side. The pixel drive circuit formation layer L1 may include, for example, a signal line drive circuit and a scanning line drive circuit (not illustrated) for displaying an image. For details of the respective components, descriptions will be given later.

Fig. 2 illustrates a whole configuration of the display unit 1. The display unit 1 has a display region 110 on the support substrate 11, and may be used, as, for example, an ultrathin-type organic light emitting color display unit or the like. Around the display region 110 on the support substrate 11, for example, a signal line drive circuit 120 and a scanning line drive circuit 130 that are drivers for displaying an image may be provided. In the display region 110, the plurality of organic EL devices 20 (20R, 20G, and 20B) two-dimensionally arranged in a state of matrix and a pixel drive circuit 140 for driving the organic EL devices 20 are formed. The

organic EL devices

20R, 20G, and 20B respectively refer to the organic EL devices 20 that emit red light, green light, and blue light.

Fig. 3 illustrates an example of the pixel drive circuit 140. The pixel drive circuit 140 is an active-type drive circuit formed in a layer under an after-mentioned first electrode 21 (Fig. 1). That is, the pixel drive circuit 140 has a drive transistor Tr1, a writing transistor Tr2, a capacitor (retentive capacity) Cs between the transistors Tr1 and Tr2, and the

organic EL devices

20R, 20G, or 20B that is serially connected to the drive transistor Tr1 between a first power line (Vcc) and a second power line (GND). Each of the drive transistor Tr1 and the writing transistor Tr2 is configured of a general Thin Film Transistor (TFT).

In the pixel drive circuit 140, a plurality of signal lines 120A are arranged in a column direction, and a plurality of scanning lines 130A are arranged in a row direction. One of the

organic EL devices

20R, 20G, and 20B is provided in every intersection of each signal line 120A and each scanning line 130A. Each signal line 120A is connected to the signal line drive circuit 120, and each scanning line 130A is connected to the scanning line drive circuit 130. An image signal is sequentially supplied from the signal line drive circuit 120 to a source electrode of the transistor Tr2, and a scanning signal is sequentially supplied from the scanning line drive circuit 130 to a gate electrode of the transistor Tr2.

(Configuration of Main Section of Display Unit 1)
Next, a description will be given of detailed configurations of the support substrate 11, the pixel drive circuit formation layer L1, the light emitting device formation layer L2, the opposed substrate 33, and the like referring to Fig. 1 again.

The support substrate 11 may be formed of, for example, quartz, glass, a silicon (Si) wafer, a metal foil, or a film or sheet made of a resin. As the foregoing glass, for example, high-strain point glass, soda glass (Na₂O, CaO, and SiO₂), borosilicate glass (Na₂O, B₂O₃, and SiO₂), forsterite (2MgO and SiO₂), lead glass (Na₂O, PbO, and SiO₂) or the like may be used. As a resin material, for example, polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), polyvinyl alcohol (PVA), polyvinyl phenol (PVP), polyether sulfone (PES), polyimide, a polycarbonate resin, or the like may be used. In the case where the support substrate 11 is formed with the use of the resin material, the support substrate 11 may preferably have a laminated structure and be subjected to surface treatment in order to suppress water permeability and gas permeability. Since light is extracted from the opposed substrate 33 in a top-emission type display unit, the support substrate 11 may be formed of a transmissive material or a non-transmissive material. The support substrate 11 may be made of a flexible material to achieve a bendable display unit. Values of the Young's modulus and the curvature radius of the support substrate 11 are not limited.

The pixel drive circuit formation layer L1 has

interlayer insulating layers

16A and 16B in which a TFT 10T (the drive transistor Tr1 and the writing transistor Tr2 of Fig. 3) and a wiring 17 are buried.

The TFT 10T includes a gate electrode 12, a gate insulating film 13, and a semiconductor layer having source-

drain regions

14A and 14B and a channel region 15. The channel region 15 of the semiconductor layer is provided in a position opposed to the gate electrode 12. The gate insulating film 13 is interposed between the semiconductor layer and the gate electrode 12. In the semiconductor layer, the source-drain region 14A and the source-drain region 14B are provided with the channel region 15 in between. The TFT 10T is electrically connected to the organic EL device 20 through the wiring 17. For the semiconductor layer, for example, a-Si (amorphous silicon), oxide semiconductor, organic semiconductor, or the like may be used. In Fig. 1, a so-called bottom-gate type transistor in which the gate electrode 12 is provided on the substrate 11 is illustrated. However, the TFT 10T may be a top-gate type transistor.

The

interlayer insulating layers

16A and 16B planarize the surface of the support substrate 11 on which the pixel drive circuit 140 (such as the TFT 10T) is formed. The

interlayer insulating layers

16A and 16B may be preferably made of a material having favorable pattern accuracy, since a fine connection hole is provided therein. The wiring 17 electrically connects the source-

drain regions

14A and 14B of the TFT 10T and the organic EL device 20 (an after-mentioned first electrode 21). The wiring 17 is connected to the source-

drain regions

14A and 14B of the TFT 10T through a contact provided in the interlayer insulating layer 16A in a lower layer (on the support substrate 11 side), and to the first electrode 21 through a contact provided in the connection hole of the interlayer insulating layer 16B in an upper layer (on the opposed substrate 33 side). Examples of constituent materials of the

interlayer insulating layers

16A and 16B may include an organic material such as polyimide and an inorganic material such as silicon oxide (SiO₂), silicon nitride. (SiNx), and silicon oxynitride (SiON).

The organic EL device 20, an insulating layer (a dividing wall) 24, a protective layer 31, and an adhesive layer 32 are provided in the light emitting device formation layer L2. The protective layer 31 and an adhesive layer 32 cover the organic EL device 20 and the insulating layer 24. In the organic EL device 20, the first electrode 21 as an anode electrode, an organic layer 23, a semi-transmissive reflecting film 40, a resistance layer 50, and a second electrode 22 as a cathode electrode are laminated in this order from the support substrate 11 side.

The first electrode 21 is an electrode to inject holes into the organic layer 23 (an after-mentioned hole transport layer 23B in Fig. 4A), and is provided on the interlayer insulating layer 16B for each of the organic EL devices 20 (20R, 20G, and 20B). The first electrode 21 also has a function as a reflection layer, and may preferably have high reflectance as much as possible in order to improve light emission efficiency. The first electrode 21 may be made of, for example, a metal element such as platinum (Pt), gold (Au), silver (Ag), chromium (Cr), tungsten (W), nickel (Ni), copper (Cu), iron (Fe), cobalt (Co), tantalum (Ta), aluminum (Al), neodymium (Nd), and molybdenum (Mo), or an alloy thereof. For example, as such an alloy, Ag-Pd-Cu alloy that has silver as a main component and contains 0.3 wt% to 1 wt% of palladium (Pd) and 0.3 wt% to 1 wt% of copper or Al-Nd alloy may be used. By providing an appropriate hole injection layer, it becomes possible to use a material that has a disadvantage of hole injection barrier due to existence of a surface oxide film and a small work function in spite of its high reflectance such as aluminum element and an aluminum alloy as the first electrode 21. A transparent conductive film made of an oxide of indium and tin (ITO) and an oxide of indium and zinc (IZO) may be provided on the surface of the first electrode 21. The thickness of the first electrode 21 may be, for example, from 0.01 micrometers to 1 micrometer both inclusive.

The insulating layer 24 secures insulation between the first electrode 21 and the second electrode 22, and obtains a desired shape of the light emission region. An opening 25 is provided correspondingly to the light emission region. The organic layer 23 is provided in the opening 25. The insulating layer 24 may be, for example, tapered. The opening 25 is gradually widened as the position thereof goes from the first electrode 21 side to the second electrode 22 side. The insulating layer 24 may be made of, for example, an inorganic insulating material such as SiO₂ or an organic insulating material such as a photosensitive resin material. The inorganic insulating material and the organic insulating material may be laminated. The organic layer 23 may be provided in a portion other than the opening 25 (on the insulating layer 24). However, light emission occurs only in the opening 25.

For example, as illustrated in Fig. 4A, the organic layer 23 may be configured by laminating the hole transport layer 23B, a light emission layer 23A, and an electron transport layer 23C in this order from the first electrode 21 side. A hole injection layer (not illustrated) may be provided between the first electrode 21 and the hole transport layer 23B, and an electron injection layer (not illustrated) may be provided between the electron transport layer 23C and the second electrode 22. Of the foregoing layers, the layers other than the light emission layer 23A may be provided as necessary. The organic layer 23 may be provided, for example, for each of the

organic EL devices

20R, 20G, and 20B (Fig. 1). The organic layer 23 may be provided commonly to the

organic EL devices

20R, 20G, and 20B, and, for example, white light may be emitted (not illustrated). It is possible that a laminated structure of the hole transport layer 23B, the light emission layer 23A, and the electron transport layer 23C is regarded as one tandem unit, and two or more tandem units are laminated in the respective

organic EL devices

20R, 20G, and 20B.

The hole transport layer 23B effectively transports holes generated in the first electrode 21 to the light emission layer 23A. The thickness thereof may be, for example, from 10 nm to 200 nm both inclusive. For the hole transport layer 23B, for example, 4,4',4''-tris(3-methylphenyl phenylamino)triphenylamine (m-MTDATA) or alpha-naphthylphenyldiamine (alpha NPD) may be used. The hole transport layer 23B of the

organic EL devices

20R, 20G, and 20B may be made of, for example, the same material.

In the light emission layer 23A, when an electric field is applied, electron-hole recombination is generated, and thereby light is generated. For example, the light emission layer 23A of the organic EL device 20R emits red light, the light emission layer 23A of the organic EL device 20G emits green light, and the light emission layer 23A of the organic EL device 20B emits blue light. The thickness of the light emission layer 23A may be, for example, from 1 nm to 100 nm both inclusive.

The light emission layer 23A of the organic EL device 20R may have a thickness of, for example, about 5 nm, and may be composed of a compound obtained by mixing 30 wt% of 2,6-bis<(4'-methoxydiphenylamino)styryl>-1,5-dicyanonaphthalene (BSN) in 4,4-bis(2,2-diphenylvinyl)biphenyl (DPVBi).

The light emission layer 23A of the organic EL device 20G may have a thickness of, for example, about 10 nm, and may be composed of a compound obtained by mixing 5 wt% of coumarin 6 in DPVBi.

The light emission layer 23A of the organic EL device 20B may have a thickness of, for example, about 30 nm, and may be composed of a compound obtained by mixing 2.5 wt% of 4,4'-bis<2-{4-(N,N-diphenylamino)phenyl}vinyl>biphenyl (DPAVBi) in DPVBi.

The electron transport layer 23C improves efficiency of transporting electron to the light emission layer 23A. The electron transport layer 23C may be configured of, for example, quinolone, perylene, phenanthroline, phenanthrene, pyrene, bisstyryl, pyrazine, triazole, oxazole, fullerene, oxadiazole, fluorenone, anthracene, naphthalene, butadiene, coumarin, acridine, stilbene, a derivative thereof, or a metal complex. The thickness of the electron transport layer 23C may be, for example, from 5 nm to 300 nm both inclusive. For the electron transport layer 23C, for example, 8-hydroxyquinolinealuminum (abbreviation: Alq₃) having a thickness of about 20 nm may be used. Each electron transport layer 23C of the

organic EL devices

20R, 20G, and 20B may be, for example, made of the same material.

The semi-transmissive reflecting film 40 configures a resonator structure of the organic EL device 20, and may be provided, for example, commonly to all the organic EL devices 20. More specifically, light from the light emission layer 23A is resonated between an interface P1 (a first interface) between the first electrode 21 and the organic layer 23 (the hole transport layer 23B in Fig. 4A) and an interface P2 (a second interface) between the semi-transmissive reflecting film 40 and the organic layer 23 (the electron transport layer 23C in Fig. 4A), and part thereof is extracted from the second electrode 22 through the semi-transmissive reflecting film 40. Since the organic EL device 20 has such a resonance structure, the light emitted in the light emission layer 23A generates multiple interference, and the half bandwidth of spectrum of light extracted from the second electrode 22 side is decreased. That is, light radiation intensity in a front direction is allowed to be increased, and color purity of light emission is allowed to be improved. Further, outside light entering from the opposed substrate 33 side is attenuated due to multiple interference, and therefore, the reflectance thereof is decreased. It is to be noted that the display unit 1 may be configured without providing the semi-transmissive reflecting film 40.

Where an optical distance from the interface P1 to the maximum light emission position of the light emission layer 23A is OL₁, and an optical distance from the interface P2 to the maximum light emission position is OL₂, OL₁ and OL₂ may satisfy, for example, the following Mathematical expression 1 and the following Mathematical expression 2. The maximum light emission position (maximum light emission position M1) may be, for example, an interface between the electron transport layer 23C and the light emission layer 23A (Fig. 4A). The maximum light emission position (maximum light emission position M2) may be an interface between the hole transport layer 23B and the light emission layer 23A as illustrated in Fig. 4B. For example, the maximum light emission position is M1 for the organic EL device 20R, and the maximum light emission position is M2 for the

organic EL devices

20G and 20B.

(In Mathematical expression 1 and Mathematical expression 2, OL₁ represents the optical distance from the interface P1 to the maximum light emission position of the light emission layer 23A; OL₂ represents the optical distance from the interface P2 to the maximum light emission position; R represents the maximum peak wavelength of the spectrum of the light generated in the light emission layer 23A; F₁ represents a phase shift amount of reflected light generated in the interface P1 (unit: radian, and -2P<F₁<=0); F₂ represents a phase shift amount of reflected light generated in the interface P2 (unit: radian, and -2P<F₂<=0); C represents a circular constant; and values of (m₁, m₁) are any of (0, 0), (1, 0), and (0, 1).)

By defining interference conditions or resonance conditions of light configured by the organic layer 23, the first electrode 21, and the semi-transmissive reflecting film 40 of the organic EL device 20 as described above, dependence of luminance and chromaticity on view angle is allowed to be decreased.

The semi-transmissive reflecting film 40 may contain, for example, an alkali metal or an alkali earth metal, and silver. Specifically, the semi-transmissive reflecting film 40 contains magnesium (Mg) and silver, and the volume ratio thereof (Mg:Ag) may range, for example, from 5:1 to 30:1 (Mg:Ag =5:1 to 30:1). The semi-transmissive reflecting film 40 may contain, for example, magnesium and calcium (Ca), and the volume ratio thereof (Mg:Ca) may range, for example, from 2:1 to 10:1 (Mg:Ca=2:1 to 10:1). The semi-transmissive reflecting film 40 may be made of aluminum or silver. The thickness of the semi-transmissive reflecting film 40 may be, for example, from about 1 nm to about 6 nm both inclusive.

The semi-transmissive reflecting film 40 has a breaking section 40A. The semi-transmissive reflecting film 40 having a thin film thickness (such as a thickness from 1 nm to 6 nm both inclusive) as described above is less likely to be formed on side walls of the insulating layer 24, and the breaking section 40A may be provided, for example, on the side walls of the insulating layer 24. Therefore, as illustrated in Fig. 5, the breaking section 40A exists around the opening 25.

The resistance layer 50 is provided between the organic layer 23 and the second electrode 22, specifically, between the semi-transmissive reflecting film 40 and the second electrode 22 over the whole surface of the display region 110 on the support substrate 11, and has an electric resistance higher than that of the first electrode 21 and the second electrode 22. In this embodiment, the resistance layer 50 contains zinc oxide (ZnO), and a crystal orientation of zinc oxide includes a plurality of plane indices components. Thereby, although details will be described later, short-circuit between the first electrode 21 and the second electrode 22 is allowed to be more securely prevented, and light extraction efficiency is allowed to be improved. The resistance layer 50 includes a charge transport function or a charge injection function. The resistance layer 50 may be provided in any position, as long as the position is located between the organic layer 23 and the second electrode 22. For example, in the case where the display unit 1 is configured without providing the semi-transmissive reflecting film 40, the resistance layer 50 may be provided between the electron transport layer 23C and the second electrode 22. Further, in the case where the electron transport layer 23C is omitted, the resistance layer 50 may be provided between the light emission layer 23A and the second electrode 22.

A current flowing through the resistance layer 50 may be preferably one-tenth or about one-tenth of a current flowing through one entire organic EL device 20. The electric resistivity of the resistance layer 50 may be, for example, from 1*10² ohm meter to 1*10⁶ ohm meter both inclusive (from 1*10⁴ ohm meter to 1*10⁸ ohm meter both inclusive). The thickness of the resistance layer 50 may be, for example, from 0.1 micrometers to 10 micrometers both inclusive. More specifically, the electric resistivity of the resistance layer 50 may be preferably from 5*10² ohm meter to 5*10⁴ ohm meter both inclusive (from 5*10⁴ ohm meter to 5*10⁶ ohm meter both inclusive), ant the thickness of the resistance layer 50 may be preferably from 0.15 micrometers to 1 micrometer both inclusive. As described above, the resistance layer 50 contains zinc oxide. The crystal orientation of zinc oxide may include, for example, (002) plane indices component and (101) plane indices component. The crystal orientation of zinc oxide may include, for example, (001) component or (212) component in addition to the (002) component and the (101) component. It is sufficient that the crystal orientation of zinc oxide include two or more components thereof. Since the crystal orientation of zinc oxide includes the plurality of plane indices components, film stress of the resistance layer 50 is allowed to be decreased, and a voltage is allowed to be securely applied to the organic layer 23. A ratio of the (101) component with respect to the (002) component ((101)/(002)) may be preferably equal to or larger than 5%, and may be preferably equal to or larger than 15%. By containing the (101) component at a rate of 5% or more with respect to the (002) component, film stress of the resistance layer 50 is allowed to be suppressed, and the organic EL device 20 is allowed to emit light securely. Zinc oxide has optical characteristics closer to those of the organic layer 23 than other high resistance material such as niobium oxide (Nb₂O₅), extraction efficiency of light generated in the light emission layer 23A is improved, and power consumption is allowed to be suppressed. The resistance layer 50 may preferably contain zinc oxide at a rate of 30% or more.

The resistance layer 50 may preferably contain an additive together with zinc oxide in order to improve optical characteristics and to adjust resistivity. Examples of components of such an additive may include a transition metal element, a metalloid element, and a light element having atomic number of 30 or less. Specific examples thereof may include tin (Sn), indium (In), gallium (Ga), magnesium (Mg), calcium (Ca), aluminum (Al), silicon (Si), thallium (Tl), bismuth (Bi), and lead (Pb). Of the foregoing, magnesium, aluminum, and silicon may be preferably contained. A plurality of these elements may be contained in the resistance layer 50. The resistance layer 50 may contain such an additive, for example, at a rate of about 10% to 20% both inclusive. The resistance layer 50 may be an amorphous film. In the case where the resistance layer 50 is formed of a dense film having low water permeability, the display unit 1 may be configured without providing the after-mentioned protective layer 31.

An organic layer (not illustrated) may be further provided between the semi-transmissive reflecting film 40 and the resistance layer 50. The organic layer may include a light emission layer.

The second electrode 22 is provided on the resistance layer 50 in a state of being insulated from the first electrode 21, and is provided commonly to all the organic EL devices 20. The second electrode 22 is made of a light-transmissive transparent material. Examples thereof may include ITO, IZO, zinc oxide (ZnO), alumina-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), an indium titanium oxide (ITiO), or an indium tungsten oxide (IWO). For the second electrode 22, for example, a material having volume resistivity of 1 ohm meter (100 ohm meter) or less such as ITO may be preferably used. The thickness of the second electrode 22 may be, for example, 500 nm.

The protective layer 31 may be preferably made of a material that is transparent to light generated in the light emission layer 23A, is dense, and has low water permeability. Examples of such a material may include amorphous silicon (alpha-Si), amorphous silicon carbide (alpha-SiC), amorphous silicon nitride (alpha-Si_1-xN_x), amorphous silicon oxide (alpha-Si_1-yO_y), amorphous carbon (alpha-C), amorphous oxynitride silicon, and aluminum oxide (Al₂O₃).

For the adhesive layer 32, for example, a thermoset adhesive such as an acrylic adhesive, an epoxy adhesive, a urethane-series adhesive, a silicone-series adhesive, a cyanoacrylate-series adhesive, an ultraviolet photo-curable adhesive, or the like may be used.

The opposed substrate 33 is located on the second electrode 22 side of the organic EL device 20, and seals the organic EL device 20 together with the adhesive layer 32. For the opposed substrate 33, a material similar to that of the foregoing support substrate 11 may be used as long as the material is transparent to light generated in the light emission layer 23A. In the opposed substrate 33, for example, a color filter and a light-shielding film as a black matrix (both not illustrated) may be provided.

(Method of Manufacturing Display Unit 1)
The display unit 1 as described above may be manufactured, for example, as follows (Fig. 6A to Fig. 8B).

First, the TFT 10T is formed on the support substrate 11. Specifically, after the pattern-like gate electrode 12 is provided on the support substrate 11, the gate insulating film 13 and the semiconductor layer are formed in this order to cover the gate electrode 12. Thereafter, the channel region 15 and the source-

drain regions

14A and 14B are provided in the semiconductor layer, and thereby, the TFT 10T is formed. Next, silicon oxide may be formed by, for example, a CVD (Chemical Vapor Deposition) method on the TFT 10T. Thereafter, a connection hole is provided in the silicon oxide film with the use of photolithography and etching, and then the interlayer insulating layer 16A (Fig. 6A) is formed.

Subsequently, aluminum may be formed on the interlayer insulating layer 16A by, for example, a vacuum evaporation method. Thereafter, the resultant is etched to form the wiring 17. The wiring 17 is electrically connected to the source-

drain regions

14A and 14B of the semiconductor layer through a contact provided in the interlayer insulating layer 16A. After the wiring 17 is provided, as illustrated in Fig. 6B, the interlayer insulating layer 16B made of, for example, silicon oxide may be formed. The interlayer insulating layer 16B may be formed, for example, with the use of a method similar to that of the interlayer insulating layer 16A. The interlayer insulating layer 16B has been previously provided with a connection hole in a position opposed to part of the wiring 17.

After the interlayer insulating layer 16B is provided, Al-Nd alloy may be formed by, for example, a vacuum evaporation method, the resultant is etched to form the pattern-like first electrode 21 (Fig. 6C). The first electrode 21 has been electrically connected to the wiring 17 through a contact provided in the interlayer insulating layer 16B. Next, the insulating layer 24 made of polyimide being 1 micrometer thick may be formed by, for example, a spin coating method. Thereafter, the insulating layer 24 is etched to expose part or all of the first electrode 21 to provide the opening 25 (Fig. 7A).

Subsequently, as illustrated in Fig. 7B, the hole transport layer 23B, the light emission layer 23A, and the electron transport layer 23C may be formed in this order in the opening 25 with the use of, for example, a vacuum evaporation method for each of the organic EL devices 20 to form the organic layer 23. Next, the semi-transmissive reflecting film 40 made of Mg-Ag (volume ratio: Mg:Ag=10:1) having an average film thickness of 5 nm may be formed on the whole surface of the display region 110 (Fig. 2) with the use of, for example, a vacuum evaporation method (Fig. 8A). Since the breaking section 40A is provided in the semi-transmissive reflecting film 40, the semi-transmissive reflecting film 40 may be preferably formed at comparatively low pressure such as 1*10^-3 Pa or less. At this time, by forming the semi-transmissive reflecting film 40 continuously following the organic layer 23 in the same vacuum evaporation apparatus as that of the organic layer 23, degradation of the organic layer 23 due to moisture and oxygen in the atmosphere is allowed to be prevented.

After the semi-transmissive reflecting film 40 is provided, the resistance layer 50 containing zinc oxide is formed on the semi-transmissive reflecting film 40. For example, the resistance layer 50 may have a thickness of 0.5 micrometers, and the electric resistivity thereof may be 1*10⁴ ohm meter (1*10⁶ ohm meter). In order to improve coverage, the resistance layer 50 may be preferably formed at comparatively high pressure of, for example, from 0.1 Pa to 10 Pa both inclusive.

The resistance layer 50 may be preferably formed not to excessively crystalize zinc oxide so that the crystal orientation of zinc oxide contained in the resistance layer 50 include the plurality of plane indices components such as the (101) component together with the (002) component. For example, in the case where the resistance layer 50 is formed by a sputtering method, if a limitation plate is used, the number of sputtering particles with high energy is reduced, and thereby, excessive crystallization is allowed to be prevented. Alternatively, setting may be made so that sputtering particles collide with carrier gas molecules five times or more until the sputtering particles reach the substrate. Specifically, first, a substrate rotation sputtering deposition equipment is used, and the limitation plate is provided in a position located significantly close to a target. Next, 1.5% of oxygen (O₂) with respect to argon (Ar) is introduced, and the resistance layer 50 may be formed, for example, at chamber pressure of 0.7 Pa. The chamber pressure is adjusted so that the sputtering particles collide with the carrier gas molecules five times or more until the sputtering particles reach the substrate. Thereby, for example, zinc oxide having crystal orientation in which a rate of the (101) component with respect to the (002) component is 10% is formed. As described above, the resistance layer 50 may be formed by mixing the additive therewith.

After the resistance layer 50 is provided, the second electrode 22 that is made of, for example, ITO and has a thickness of 0.5 micrometers may be formed on the resistance layer 50 (Fig. 8B). The electric resistivity of the second electrode 22 may be, for example, 1 ohm meter (100 ohm meter). The second electrode 22 may be formed, for example, with the use of a vacuum evaporation method, a sputtering method, an ion plating method, or the like.

Subsequently, the protective layer 31 may be formed on the whole surface of the support substrate 11 by, for example, a CVD method or a sputtering method. Thereafter, the opposed substrate 33 is sticked to the protective layer 31 with the adhesive layer 32 in between. Specifically, after a sealing agent (not illustrated) is provided at the rim of the support substrate 11 (the protective layer 31), the adhesive layer 32 is filled inside the sealing agent to stick the opposed substrate 33 (ODF method: One Drop Fill). The adhesive layer 32 may be, for example, heated to fix the opposed substrate 33 on the support substrate 11. The adhesive layer 32 may be provided on the opposed substrate 33 side, or a sheet-like adhesive layer 32 may be used. Accordingly, the display unit 1 illustrated in Fig. 1 to Fig. 3 is completed.

(Function and Effect of Display Unit 1)
In the display unit 1, a scanning signal is supplied from the scanning line drive circuit 130 to the respective organic EL devices 20 (20R, 20G, and 20B) through the gate electrode of the writing transistor Tr2. An image signal is supplied from the signal line drive circuit 120 to the retentive capacity Cs through the writing transistor Tr2, and is retained in the retentive capacity Cs. That is, the driving transistor Tr1 is on-off controlled according to the signal retained in the retentive capacity Cs. Thereby, a drive current Id is injected into the organic EL device 20, electron-hole recombination is generated, and thereby, light is emitted. The light is multiply reflected between the first electrode 21 (the interface P1) and the semi-transmissive reflecting film 40 (the interface P2), is transmitted through the semi-transmissive reflecting film 40, the resistance layer 50, the second electrode 22, and the opposed substrate 33, and is extracted. By including such a resonator structure, the light that has been transmitted through the second electrode 22 and is emitted has a wavelength in the vicinity of the central wavelength of resonance, color purity of display light is improved, and the light intensity thereof is also improved.

In this case, the resistance layer 50 containing zinc oxide is provided between the first electrode 21 and the second electrode 22, specifically, between the semi-transmissive reflecting film 40 and the second electrode 22. Thereby, short-circuit between the first electrode 21 and the second electrode 22 is allowed to be more securely prevented, and light extraction efficiency is allowed to be improved. For details thereof, a description will be given below.

When the display unit 1 is manufactured, as illustrated in Fig. 9, a foreign matter F may adhere to the first electrode 21. Due to the foreign matter F, coverage of the organic layer 23 becomes incomplete, and a region where the organic layer 23 is not formed is generated in the vicinity of the foreign matter F. Due to a factor other than the foreign matter F such as uplift of part of the surface of the first electrode 21, the region where the organic layer 23 is not formed is generated. In such a region, the semi-transmissive reflecting film 40 above the organic layer 23 also has a gap due to its small film thickness. Therefore, in a display unit in which a resistance layer is not provided, short-circuit occurs between the first electrode and the second electrode in the vicinity of the foreign matter F, and display quality is lowered. In contrast, in PTL 2 (bottom-emission type), a method of providing a resistance layer made of an indium-oxide-series compound between an anode electrode and an organic layer is proposed. Further, in PTL 3 (top-emission type), a method of increasing a resistance of part of an anode electrode is disclosed. In PTL 4 (bottom-emission type), a method of increasing a resistance of part of a cathode electrode is disclosed. However, as described above, these methods are not allowed to sufficiently prevent occurrence of a defective device due to short-circuit.

In this embodiment, the resistance layer 50 containing zinc oxide is provided between the semi-transmissive reflecting film 40 and the second electrode 22. Therefore, the resistance layer 50 is interposed between the first electrode 21 and the second electrode 22 in the vicinity of the foreign matter F. Consequently, the first electrode 21 and the second electrode 22 are not in contact with each other directly, an excessive current concentration to the vicinity of the foreign matter F is prevented, and a voltage is allowed to be applied to the whole surface of the organic layer 23 of the organic EL device 20. Thus, short-circuit between the first electrode 21 and the second electrode 22 is allowed to be more securely prevented. It is to be noted that, even if the semi-transmissive reflecting film 40 does not exist, the resistance layer 50 has a sufficient charge transport layer, and therefore, a voltage is securely applied from the second electrode 22 to the organic layer 23.

One plausible idea is that a resistance layer between a first electrode and a second electrode may be made of a high resistance material such as niobium oxide as a main component (for example, PTLs 5 and 6). Optical characteristics of niobium oxide will be compared to those of zinc oxide below. In a resistance layer having niobium oxide as a main component, refractive index (n) at wavelength of 633 nm is from 2.3 to 2.4 both inclusive, and extinction coefficient (k) at wavelength of 450 nm is equal to or less than 0.005. In contrast, in the resistance layer 50 having zinc oxide as a main component, the refractive index (n) at wavelength of 633 nm is from 1.8 to 1.9 both inclusive, and the extinction coefficient (k) at wavelength of 450 nm is equal to or less than 0.001. That is, by containing zinc oxide in the resistance layer 50, optical characteristics of the resistance layer 50 become close to those of the organic layer 23, and light extraction efficiency of the display unit 1 is allowed to be improved. Therefore, electric power is allowed to be saved. Further, dependence of chromaticity on view angle is decreased as well.

However, in the case where a crystal orientation of zinc oxide includes a single component such as only the (002) plane indices component, film stress of a resistance layer is increased. Thereby, the resistance layer is not allowed to be uniformly formed, and peeling-off of the film may occur between an organic layer and the resistance layer. It becomes more difficult to form a uniform film as the size of a display unit is larger. The same is applied to a case of manufacturing a small display by a large apparatus in order to improve manufacturing efficiency. The peeling-off of a film may break the organic layer, and normal light emission of an organic EL device may be prevented.

In the display unit 1, since the crystal orientation of zinc oxide of the resistance layer 50 includes the plurality of plane indices components, film stress of the resistance layer 50 is decreased. Therefore, the resistance layer 50 is uniformly formed in a plane to prevent peeling-off of the film, and a voltage is securely applied to the organic layer 23.

Fig. 10 illustrates results of measurement with the use of an X-ray diffraction method of the resistance layer 50 (zinc oxide) in which the crystal orientation includes the (002) plane indices component and the (101) plane indices component; and a resistance layer 150 (zinc oxide) in which the crystal orientation includes only the (002) plane indices component. While the number of peaks of the resistance layer 150 was one (2 theta: in the vicinity of 34 deg), two peaks (2 theta: in the vicinity of 34 deg and 36 deg) were observed in the resistance layer 50.

Fig. 11 illustrates a relation between a ratio of the (101) component with respect to the (002) component ((101)/(002)) and stress. It is to be noted that (101)/(002) is obtained from peak intensity ratio of the X-ray analysis. From Fig. 11, it is found that as the (101) component became increased, the stress became decreased. In a film in which (101)/(002) was less than 5% (0.005), that is, the absolute value of the stress was larger than -400 MPa, defective organic EL devices were frequently seen. In contrast, in a film in which (101)/(002) was equal to or larger than 5%, the almost all organic EL devices 20 normally emitted light. In a film having a reduced stress (a so-called stress-free film) in which the absolute value of the stress was smaller than 250 MPa ((101)/(002) was equal to or larger than 15%), all the organic EL devices 20 were allowed to normally emit light more securely. The rate of the defective organic EL devices was equal to or larger than 30% in the case where the crystal orientation of zinc oxide included only the (002) plane indices component, was 0.1929% in the case where (101)/(002) was 1.9%, was 0.0096% in the case where (101)/(002) was 17.1%, and was 0.0039% in the case where (101)/(002) was 46.2%.

As described above, in this embodiment, the resistance layer 50 containing zinc oxide is provided between the first electrode 21 and the second electrode 22, and the crystal orientation of zinc oxide includes the plurality of plane indices components. Therefore, short-circuit between the first electrode 21 and the second electrode 22 is allowed to be more securely prevented, and light extraction efficiency is allowed to be improved.

A description will be given below of modifications of the foregoing embodiment. In the following description, for the same components as the components in the foregoing embodiment, the same referential symbols are affixed thereto, and the description thereof will be omitted as appropriate.

(Modification 1)
Fig. 12 illustrates a cross-sectional configuration of a display unit (display unit 1A) according to Modification 1. The display unit 1A has a conductive resin layer 60 between the resistance layer 50 and the second electrode 22. Except for the foregoing point, the display unit 1A has a configuration similar to that of the display unit 1, and the operation and the effect thereof are similar to those of the display unit 1.

The conductive resin layer 60 supports conduction between the second electrode 22 and the resistance layer 50. The electric resistivity of the conductive resin layer 60 may be, for example, from 1*10^-4 ohm meter to 1*10² ohm meter both inclusive (from 1*10^-2 ohm meter to 1*10⁴ ohm meter both inclusive). The thickness thereof may be, for example, from 1 micrometer to 100 micrometers both inclusive. For the conductive resin layer 60, for example, a material obtained by containing a conductive polymer in a resin material may be used. Examples of the resin material may include a thermoset resin such as an acrylic resin, an epoxy resin, an urethane-series resin, a silicone-series resin, and a cyanoacrylate-series resin, or an ultraviolet photo-curable resin. Examples of the conductive polymer may include polypyrrole, polyether, polyaniline, and polythiophene. The conductive resin layer 60 may be made of a copolymer. The copolymer may be formed by, for example, copolymerizing a conductive polymer such as pyrrole and thiophene with an acrylic polymer, an epoxy polymer, an urethane-series polymer, a silicone-series polymer, or a cyanoacrylate-series polymer.

In the display unit 1A having the conductive resin layer 60, the protective layer 31 and the adhesive layer 32 may be omitted (Fig. 12). Such a display unit 1A is allowed to be manufactured by adhering the opposed substrate 33 provided with the second electrode 22 to the support substrate 11 provided with the organic layer 23. That is, since the step of forming the second electrode 22 on the organic layer 23 is allowed to be omitted, degradation of the organic layer 23 is allowed to be prevented. Further, the high-quality second electrode 22 is allowed to be formed.

(Modification 2)
Fig. 13 illustrates a cross-sectional configuration of a display unit (display unit 1B) according to Modification 2. The display unit 1B has an auxiliary electrode 70. The auxiliary electrode 70 electrically connects the second electrode 22 to an external circuit. Except for the foregoing point, the display unit 1B has a configuration similar to that of the display unit 1, and the operation and the effect thereof are similar to those of the display unit 1.

The auxiliary electrode 70 may be electrically connected to the second electrode 22 by a conductive rib 71 provided in the adhesive layer 32, for example. The rib 71 may be obtained by providing a conductive material film on the surface of a rib made of, for example, a polyimide resin, an acryl resin, or the like. Examples of the conductive material film may include aluminum, silver, copper, titanium, tungsten, tantalum, molybdenum, ITO, IZO, and tin oxide. The height of the rib 71 may be, for example, 5 micrometers. The auxiliary electrode 70 may be made of, for example, aluminum being 1 micrometer thick.

(Modification 3)
Fig. 14 illustrates a cross-sectional configuration of a display unit (display unit 1C) according to Modification 3. The display unit 1C has an extraction electrode 80. The extraction electrode 80 connects the second electrode 22 to an external circuit. Except for the foregoing point, the display unit 1C has a configuration similar to that of the display unit 1, and the operation and the effect thereof are similar to those of the display unit 1.

As illustrated in Fig. 15, the extraction electrode 80 may be provided, for example, in a state of a frame on the rim of the opposed substrate 33. Part thereof is superimposed on the second electrode 22 (superimposed section 80A). The extraction electrode 80 may be made of, for example, titanium. The extraction electrode 80 may be provided on the support substrate 11 side (Fig. 16).

(Module and Application Examples)
A description will be given of application examples of the display unit described in the foregoing embodiment. The display unit 1 of the foregoing embodiment is applicable to a display unit of an electronic device in any field for displaying a video signal inputted from outside or a video signal generated inside as an image or a video such as a television, a digital camera, a notebook personal computer, a portable terminal device such as a mobile phone, and a video camcorder.

(Module)
The

display units

1, 1A, 1B, and 1C (referred to as the display unit 1 below) of the foregoing embodiment and the like may be incorporated in various electronic apparatuses such as after-mentioned Application examples 1 to 5 as a module as illustrated in Fig. 17, for example. In the module, for example, a region 210 exposed from the protective layer 31 and the opposed substrate 33 is provided on a side of the support substrate 11, and an external connection terminal (not illustrated) is formed in the exposed region 210 by extending the wirings of the signal line drive circuit 120 and the scanning line drive circuit 130. The external connection terminal may be provided with a flexible printed circuit (FPC) 220 to input and output a signal.

(Application Example 1)
Fig. 18 illustrates an appearance of a television to which the display unit 1 of the foregoing embodiment is applied. The television may have, for example, an image display screen section 300 including a front panel 310 and a filter glass 320. The image display screen section 300 is configured of the display unit 1 according to the foregoing embodiment.

(Application Example 2)
Figs. 19A and 19B illustrate appearances of a digital camera to which the display unit 1 of the foregoing embodiment or the like is applied. The digital camera may have, for example, a light emission section 410 for a flash, a display section 420, a menu switch 430, and a shutter button 440. The display section 420 is configured of the display unit 1 according to the foregoing embodiment.

(Application Example 3)
Fig. 20 illustrates an appearance of a notebook personal computer to which the display unit 1 of the foregoing embodiment or the like is applied. The notebook personal computer may have, for example, a main body 510, a keyboard 520 for operation of inputting characters and the like, and a display section 530 for displaying an image. The display section 530 is configured of the display unit 1 according to the foregoing embodiment.

(Application Example 4)
Fig. 21 illustrates an appearance of a video camcorder to which the display unit 1 of the foregoing embodiment is applied. The video camcorder may have, for example, a main body 610, a lens 620 for shooting a subject provided on the front side surface of the main body 610, a start-stop switch 630 for shooting, and a display section 640. The display section 640 is configured of the display unit 1 according to the foregoing embodiment.

(Application Example 5)
Figs. 22A and 22B illustrate appearances of a mobile phone to which the display unit 1 of the foregoing embodiment is applied. In the mobile phone, for example, an upper package 710 and a lower package 720 may be jointed by a joint section (hinge section) 730. The mobile phone may have a display 740, a sub-display 750, a picture light 760, and a camera 770. Either one or both of the display 740 and the sub-display 750 are configured of the display unit 1 according to the foregoing embodiment.

(Application Example 6)
Fig. 23 illustrates an appearance of a smartphone (multifunctional telephone) to which the display unit 1 of the foregoing embodiment is applied. The smartphone may be configured of, for example, a display section 810 and non-display section 820. The smartphone is allowed to be operated by the display section 810, that is, the display section 810 has a touch panel. The display section 810 is configured of the display unit 1 according to the foregoing embodiment.

While the present technology has been described with reference to the preferred embodiment and the modifications, the present technology is not limited to the foregoing embodiment and the like, and various modifications may be made. For example, the material, the thickness, the film-forming method, the film-forming conditions, and the like of each layer are not limited to those described in the foregoing embodiment, and other material, other thickness, other film-forming method, and other film-forming conditions may be adopted.

Further, in the foregoing embodiment and the like, the description has been given of the case in which the light emission layer 23A of the organic layer 23 emits red light, green light, and blue light. However, emitted light may be other color light such as white light and yellow light. Further, for example, in the foregoing embodiment and the like, the description has been given of the active-matrix type display unit. However, the present technology is applicable to a passive-matrix type display unit.

Further, in the foregoing embodiment and the like, the description has been given of the case in which the first electrode 21 is an anode and the second electrode 22 is a cathode. However, in an opposite manner, the first electrode 21 may be a cathode and the second electrode 22 may be an anode. In addition thereto, light may be extracted from the support substrate 11 side (bottom-emission type).

Furthermore, the present technology is applicable to a display unit not having a resonator structure.

In addition thereto, in the foregoing embodiment and the like, the description has been given of the case in which the resistance layer 50 between the first electrode 21 and the second electrode 22 contains zinc oxide. However, the second electrode 22 may contain zinc oxide. A crystal orientation of zinc oxide includes a plurality of plane indices components. Thereby, stress of the second electrode 22 is relaxed. Accordingly, even in the case of a large-size display unit (display), the whole surface thereof is allowed to be lighted more stably.

It is to be noted that the technology may be configured as follows.
(1) A light emitting device including:
a first electrode;
an organic layer including a light emission layer;
a resistance layer including zinc oxide; and
a second electrode,
the first electrode, the organic layer, the resistance layer and the second electrode being provided in this order,
wherein a crystal orientation of the zinc oxide includes a plurality of plane index components.
(2) The light emitting device according to (1), wherein the crystal orientation of the zinc oxide includes a (002) component and one or more of components other than the (002) component.
(3) The light emitting device according to (1) or (2), wherein the crystal orientation of the zinc oxide includes (002) component and (101) component.
(4) The light emitting device according to (3), wherein a rate of the (101) component with respect to the (002) component ((101)/(002)) of the zinc oxide is equal to or more than about 5 percent.
(5) The light emitting device according to any one of (1) to (4), wherein volume resistivity of the resistance layer is from about 1*10² ohm meter to about 1*10⁶ ohm meter both inclusive, and a thickness thereof is from about 0.1 micrometers to about 10 micrometers both inclusive.
(6) The light emitting device according to any one of (1) to (5), wherein volume resistivity of the resistance layer is from about 5*10² ohm meter to about 5*10⁴ ohm meter both inclusive, and a thickness thereof is from about 0.15 micrometers to about 1 micrometer both inclusive.
(7) The light emitting device according to any one of (1) to (6), wherein the zinc oxide includes a plurality of peaks in X-ray diffraction.
(8) The light emitting device according to any one of (1) to (7), wherein the resistance layer includes an additive together with the zinc oxide.
(9) The light emitting device according to (8), wherein the additive includes one or more elements of tin (Sn), indium (In), gallium (Ga), magnesium (Mg), calcium (Ca), aluminum (Al), silicon (Si), thallium (Tl), bismuth (Bi), and lead (Pb).
(10) The light emitting device according to any one of (1) to (9), wherein
a semi-transmissive reflecting film is included between the resistance layer and the organic layer, and
light from the light emission layer is resonated between a first interface between the first electrode and the organic layer and a second interface between the semi-transmissive reflecting film and the organic layer.
(11) A display unit provided with a plurality of light emitting devices, each of the light emitting devices, including:
a first electrode;
an organic layer including a light emission layer;
a resistance layer including zinc oxide; and
a second electrode,
the first electrode, the organic layer, the resistance layer and the second electrode being provided in this order,
wherein a crystal orientation of the zinc oxide includes a plurality of plane index components.
(12) An electronic apparatus provided with a display unit, the display unit being provide with a plurality of light emitting devices, each of the light emitting devices, including:
a first electrode;
an organic layer including a light emission layer;
a resistance layer including zinc oxide; and
a second electrode,
the first electrode, the organic layer, the resistance layer and the second electrode being provided in this order,
wherein a crystal orientation of the zinc oxide includes a plurality of plane index components.

The present disclosure contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2012-167986 filed in the Japan Patent Office on July 30, 2012, the entire contents of which is hereby incorporated by reference.

It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alternations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.

References Signs List

1, 1A, 1B display unit
11 support substrate
12 gate electrode
13 gate insulating film
14A, 14B source-drain region
15 channel region
16A, 16B interlayer insulating layer
17 wiring
10T TFT
20, 20R, 20G, 20B organic EL device
21 first electrode
22 second electrode
23 organic layer
23A light emission layer
23B hole transport layer
23C electron transport layer
24 insulating layer
25 opening
31 protective layer
32 adhesive layer
33 opposed substrate
40 semi-transmissive reflecting film
40A breaking section
50 resistance layer
60 conductive resin layer
70 auxiliary electrode
71 rib
80 extraction electrode

Claims

A light emitting device comprising:
a first electrode;
an organic layer including a light emission layer;
a resistance layer including zinc oxide; and
a second electrode,
the first electrode, the organic layer, the resistance layer and the second electrode being provided in this order,
wherein a crystal orientation of the zinc oxide includes a plurality of plane index components.
The light emitting device according to claim 1, wherein the crystal orientation of the zinc oxide includes a (002) component and one or more of components other than the (002) component.
The light emitting device according to claim 1, wherein the crystal orientation of the zinc oxide includes (002) component and (101) component.
The light emitting device according to claim 3, wherein a rate of the (101) component with respect to the (002) component ((101)/(002)) of the zinc oxide is equal to or more than about 5 percent.
The light emitting device according to claim 1, wherein volume resistivity of the resistance layer is from about 1*10² ohm meter to about 1*10⁶ ohm meter both inclusive, and a thickness thereof is from about 0.1 micrometers to about 10 micrometers both inclusive.
The light emitting device according to claim 1, wherein volume resistivity of the resistance layer is from about 5*10² ohm meter to about 5*10⁴ ohm meter both inclusive, and a thickness thereof is from about 0.15 micrometers to about 1 micrometer both inclusive.
The light emitting device according to claim 1, wherein the zinc oxide includes a plurality of peaks in X-ray diffraction.
The light emitting device according to claim 1, wherein the resistance layer includes an additive together with the zinc oxide.
The light emitting device according to claim 8, wherein the additive includes one or more elements of tin (Sn), indium (In), gallium (Ga), magnesium (Mg), calcium (Ca), aluminum (Al), silicon (Si), thallium (Tl), bismuth (Bi), and lead (Pb).
The light emitting device according to claim 1, wherein
a semi-transmissive reflecting film is included between the resistance layer and the organic layer, and
light from the light emission layer is resonated between a first interface between the first electrode and the organic layer and a second interface between the semi-transmissive reflecting film and the organic layer.
A display unit provided with a plurality of light emitting devices, each of the light emitting devices, comprising:
a first electrode;
an organic layer including a light emission layer;
a resistance layer including zinc oxide; and
a second electrode,
the first electrode, the organic layer, the resistance layer and the second electrode being provided in this order,
wherein a crystal orientation of the zinc oxide includes a plurality of plane index components.
An electronic apparatus provided with a display unit, the display unit being provide with a plurality of light emitting devices, each of the light emitting devices, comprising:
a first electrode;
an organic layer including a light emission layer;
a resistance layer including zinc oxide; and
a second electrode,
the first electrode, the organic layer, the resistance layer and the second electrode being provided in this order,
wherein a crystal orientation of the zinc oxide includes a plurality of plane index components.