JP2012204017A - Organic electroluminescent element and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL element which is improved in light extraction efficiency and capable of achieving high luminance and low power consumption, and also to provide a display device using the organic EL element.SOLUTION: The organic EL element includes: a cathode electrode 25 which is a transparent electrode; an anode electrode 24 having a first region which is constituted of at least a transparent metal layer 243 which is a metal layer to transmit light therethrough and a reflective metal layer 241 which is a metal layer to reflect the light and in which the transparent metal layer 243 and the reflective metal layer 241 are laminated, and a second region in which a transparent insulating layer 242 being an insulating layer to transmit the light therethrough is formed between the transparent metal layer 243 and the reflective metal layer 241; and an organic EL layer 23 which is formed between the cathode electrode 25 and the anode electrode 24, and emits the light to be emitted via the cathode electrode 25. The organic EL layer 23 is formed by coming into contact with the transparent metal layer 243 in the second region, and the reflective metal layer 241 reflects the light emitted from the organic EL layer 23 in the second region.

Description

  The present invention relates to an organic electroluminescence element and a display device using the same.

  In recent years, the demand for flat display devices such as liquid crystal displays having features such as thinness, light weight, and low power consumption has been rapidly increased compared to conventional CRT displays. However, the liquid crystal display has problems in viewing angle, responsiveness, and the like.

  Therefore, recently, a simple matrix method, an active matrix method, and the like using an organic electroluminescence element (hereinafter referred to as an “organic EL (Electro Luminescence) element”) that is self-luminous and has a wide viewing angle and high-speed response. The display device has attracted attention. In particular, active matrix display devices that are advantageous for high definition and large screens are being actively developed.

  A display device using an organic EL element is generally composed of a display panel using the organic EL element and a drive circuit for driving the organic EL element.

  The display panel is an organic device including a metal electrode such as Al on a substrate such as glass, a transparent electrode such as ITO (Indium Tin Oxide) opposed thereto, and a light emitting layer provided therebetween. EL elements are arranged in a matrix. The drive circuit is composed of a thin film transistor (TFT) that individually drives the organic EL elements (see, for example, Patent Document 1).

JP 2002-318556 A

  By the way, further higher luminance or lower power consumption is desired for organic EL elements.

  The present invention has been made in view of the above-described demands, and provides an organic electroluminescence element capable of improving the light extraction efficiency and thus achieving high luminance or low power consumption, and a display device using the same. With the goal.

  Here, the light extraction efficiency is a ratio at which light can be extracted to the outside, and can be represented by external output light amount / total light emission amount.

  In order to achieve the above object, an organic electroluminescence device according to an embodiment of the present invention includes a first electrode layer that is a transparent electrode, a transparent metal layer that is a metal layer that transmits light, and a metal that reflects light. A first region in which the transparent metal layer and the reflective metal layer are laminated, and a transparent insulating layer that is an insulating layer that transmits light includes the transparent metal layer and the reflective metal layer. A second electrode layer having a second region formed between the conductive metal layers, and light emitted between the first electrode layer and the second electrode layer and emitted through the first electrode layer The organic EL layer is formed in contact with the transparent metal layer in the second region, and the reflective metal layer is formed from the organic EL layer in the second region. Reflects the emitted light.

  According to the present invention, it is possible to realize an organic electroluminescence element capable of improving the light extraction efficiency and thus achieving high luminance or low power consumption, and a display device using the same.

It is sectional drawing for demonstrating the principal part of the organic EL element in Embodiment 1 of this invention. It is a figure for demonstrating an example of the element structure formed in the organic electroluminescent layer in Embodiment 1 of this invention. It is a figure for demonstrating the characteristic structure of the anode electrode in Embodiment 1 of this invention. It is a figure which shows an example of the display apparatus using the organic EL element of this invention. It is sectional drawing for demonstrating the principal part of the organic EL element in the modification of Embodiment 1 of this invention. It is sectional drawing for demonstrating the principal part of the organic EL element in Embodiment 2 of this invention.

  An organic electroluminescence device according to an embodiment of the present invention includes a first electrode layer that is a transparent electrode, a transparent metal layer that is a metal layer that transmits light, and a reflective metal layer that is a metal layer that reflects light A first region where the transparent metal layer and the reflective metal layer are laminated, and a transparent insulating layer that is an insulating layer that transmits light is formed between the transparent metal layer and the reflective metal layer. A second electrode layer having a second region formed, and an organic EL layer that is formed between the first electrode layer and the second electrode layer and emits light emitted through the first electrode layer; The organic EL layer is formed in contact with the transparent metal layer in the second region, and the reflective metal layer reflects light emitted from the organic EL layer in the second region.

  According to this configuration, since light attenuation due to plasmon generation can be suppressed when light is reflected by the second electrode layer, light extraction efficiency is improved, and high brightness and low power consumption are possible. A simple organic electroluminescence element can be realized.

  The organic electroluminescence element includes a substrate and a drive circuit layer having an active element for driving the organic EL layer on the substrate, the first electrode layer, the organic EL layer, and the second The electrode layer may be formed on the drive circuit layer.

  The second electrode layer is formed on the drive circuit layer, the organic EL layer is formed on the second electrode layer, and the first electrode layer is formed on the organic EL layer. It is good.

  With this configuration, a top emission type organic electroluminescence element can be realized.

  In the driving circuit layer, the active element is formed in a region corresponding to the outside of the second region, the first electrode layer is formed on the driving circuit layer, and the organic EL layer is It may be formed on the first electrode layer, and the second electrode layer may be formed on the organic EL layer.

  With this configuration, a bottom emission type organic electroluminescence element can be realized.

  Hereinafter, an organic EL element according to an embodiment of the present invention will be described with reference to the drawings. In the following embodiments and drawings, the same components will be described with the same reference numerals. Further, the present invention is not limited to the following embodiment.

(Embodiment 1)
Hereinafter, an organic electroluminescence display device (hereinafter referred to as an organic EL display device) according to Embodiment 1 of the present invention will be described with reference to the drawings. In the following, a top emission organic EL element of a top emission type will be described as an example, but the present invention is not limited to this.

  FIG. 1 is a cross-sectional view for explaining a main part of an organic EL element 1 according to Embodiment 1 of the present invention. FIG. 1 shows a top emission type organic EL element 1.

  An organic EL element 1 shown in FIG. 1 is laminated on a substrate 100, a drive circuit layer 11A laminated on the substrate 100, a light emitting element layer 11B laminated on the drive circuit layer 11A, and a light emitting element layer 11B. Glass substrate 105.

  The substrate 100 is, for example, a glass substrate, and constitutes a thin film transistor (TFT) together with the drive circuit layer 11A. Since the organic EL element 1 has a top emission type structure, the substrate 100 does not have to be transparent. Therefore, the substrate 100 may be formed of a non-transparent substrate, for example, a silicon substrate. The substrate 100 may be formed of a transparent or opaque flexible substrate made of resin.

  The light emitting element layer 11 </ b> B includes an organic EL layer 23, an anode electrode 24, a bank layer 30, a thin film sealing film 103, a resin sealing layer 104, and a light shielding layer 106. Since details will be described later, a description thereof is omitted here.

  The drive circuit layer 11A includes an interlayer insulating film 101 and a planarizing insulating film 102. As an active element for driving the light emitting element layer 11B in the interlayer insulating film 101 and the planarizing insulating film 102, for example, a selection transistor 21 and the drive transistor 22 are formed. In the drive circuit layer 11A, a contact hole 102a having a connection opening 25a is formed in the planarization insulating film 102.

  The selection transistor 21 and the drive transistor 22 are, for example, bottom gate type thin film transistors. The selection transistor 21 includes a gate electrode 211, a gate insulating film 212, a semiconductor layer 213, and a source / drain electrode 214 formed in order from the substrate 100. The driving transistor 22 includes a gate electrode 221, a gate insulating film 212, a semiconductor layer 223, and a source / drain electrode 224 that are sequentially formed from the substrate 100. Here, as the material of each of the electrodes described above, for example, an alloy of molybdenum (Mo) and tungsten (W), or a laminated structure of an alloy of Mo and W / aluminum (Al) / Mo and W Is mentioned. Examples of the material of the gate insulating film 212 include a silicon oxide film (SiOx) and a silicon nitride film (SiN). Note that the gate insulating film 212 may be a dielectric material in order to ensure a desired capacitance.

  Further, one of the source / drain electrodes 224 (for example, the source electrode) of the driving transistor 22 is connected to the anode electrode 24 constituting the light emitting element layer 11 </ b> B through a connection opening 25 a provided in the planarization insulating film 102. .

  The planarization insulating film 102 corresponds to the planarization insulating layer of the present invention, is formed so as to cover the active element, and planarizes the upper surface of the drive circuit layer. Specifically, the planarization insulating film 102 is formed on the interlayer insulating film 101 so as to cover the selection transistor 21 and the drive transistor 22, and planarizes the upper surface of the drive circuit layer 11A. Further, as described above, the contact hole 102a having the connection opening 25a is formed in the planarization insulating film 102. The source electrode of the driving transistor 22 and the anode electrode 24 of the light emitting element layer 11B are connected via the connection opening 25a. In other words, the contact hole 102a is formed in the region of the planarization insulating film 102 corresponding to the outside of the second region (first region), and electrically connects the transparent metal layer 243 and the drive transistor 22 which is an active element. Connecting.

  The planarization insulating film 102 is composed of a silicon oxide film formed by using, for example, a CVD method or a sputtering method. That is, the planarization insulating film 102 is formed, for example, by first forming a silicon oxide film and then planarizing the surface of the formed silicon oxide film by, for example, a CMP (Chemical Mechanical Polishing) method or the like. Is done. Note that the planarization insulating film 102 may be formed of a silicon nitride film (SiN) or the like.

  The anode electrode 24 is a reflective metal electrode formed on the planarization insulating film 102, and applies a positive voltage to the light emitting element layer 11 </ b> B with respect to the cathode electrode 25. Specifically, the anode electrode 24 corresponds to the second electrode layer of the present invention, and includes at least a transparent metal layer 243 that is a metal layer that transmits light and a reflective metal layer 241 that is a metal layer that reflects light. The first region where the transparent metal layer 243 and the reflective metal layer 241 are laminated and the transparent insulating layer 242 that is an insulating layer that transmits light are formed between the transparent metal layer 243 and the reflective metal layer 241. A second region. The reflective metal layer 241 reflects light emitted from the organic EL layer 23 in the second region. The anode electrode 24 is a characteristic component of the present application, but will not be described here because the details will be described later.

  The organic EL layer 23 corresponds to the organic EL layer of the present invention, and is formed between the first electrode layer and the second electrode layer in contact with the transparent metal layer 243 in the second region, with the first electrode layer interposed therebetween. Emits the emitted light. Specifically, the organic EL layer 23 is laminated so as to cover a partial region of the anode electrode 24, and is excited by injecting holes and electrons from the anode electrode 24 and the cathode electrode 25 and recombining them, respectively. A state is generated and emits light.

  The organic EL layer 23 is preferably formed using a light-emitting organic material that can be formed by a wet film formation method such as inkjet or spin coating. Thereby, simple and uniform film formation is possible on a large-screen substrate. The material is not particularly limited, but a polymer organic material is preferable. Features of the polymer organic material include a simple device structure, excellent film reliability, and a low-voltage driven device.

  The organic EL layer 23 may have an element structure including at least one of a hole injection layer, a hole transport layer, an organic light emitting layer, an electron injection layer, and an electron transport layer. Hereinafter, as an example, a configuration in the case where a hole injection layer, a hole transport layer, an organic light emitting layer, an electron injection layer, and an electron transport layer are formed will be described with reference to FIG.

  FIG. 2 is a diagram for explaining in detail one example of the element structure formed in the organic EL layer in the first embodiment of the present invention. In the organic EL layer 23 shown in FIG. 2, a hole injection layer 231, a hole transport layer 232, an organic light emitting layer 233, an electron transport layer 234, and an electron injection layer 235 are formed.

  The hole injection layer 231 is formed on the surface of the anode electrode 24. The hole injection layer 231 has a function of injecting holes into the organic light emitting layer 233 in a stable manner or by assisting hole generation. As a result, the drive voltage is lowered, and the lifetime of the device is extended by stabilizing the hole injection. As a material of the hole injection layer 231, for example, PEDOT (polyethylenedioxythiophene) can be used.

  The hole transport layer 232 is formed on the surface of the hole injection layer 231. The hole transport layer 232 efficiently transports holes injected from the hole injection layer 231 into the organic light emitting layer 233 and deactivates excitons at the interface between the organic light emitting layer 233 and the hole injection layer 231. It has a function to prevent and block electrons. As a material of the hole transport layer 232, for example, there is an organic polymer material having a property of transmitting generated holes by a charge transfer reaction between molecules, and examples thereof include triferamine and polyaniline.

  The electron injection layer 235 is formed on the organic light emitting layer 233. The electron injection layer 235 has a function of reducing a barrier for electron injection into the organic light emitting layer 233, lowering a driving voltage, and suppressing exciton deactivation. As a result, it is possible to stabilize the electron injection and prolong the life of the device, enhance the adhesion with the cathode electrode 25, improve the uniformity of the light emitting surface, and reduce device defects. The electron injection layer 235 is made of, for example, barium, aluminum, phthalocyanine, lithium fluoride, and a barium-aluminum laminate.

  The electron transport layer 234 is formed between the organic light emitting layer 233 and the electron injection layer 235. The electron transport layer 234 efficiently transports electrons injected from the electron injection layer 235 into the organic light emitting layer 233, and prevents deactivation of excitons at the interface between the organic light emitting layer 233 and the electron injection layer 235. Furthermore, it has a function of blocking holes.

  As described above, the element structure of the hole injection layer 231, the hole transport layer 232, the organic light emitting layer 233, the electron injection layer 235, and the electron transport layer 234 is formed in the organic EL layer 23, for example.

  Returning to the description of FIG.

  The cathode electrode 25 corresponds to the first electrode layer of the present invention, and is a transparent electrode laminated so as to cover the organic EL layer 23. The cathode electrode 25 has a function of applying a negative voltage to the organic EL layer 23 with respect to the anode electrode 24 and injecting electrons into the light emitting element layer 11B (particularly, the organic EL layer 23). The material of the cathode electrode 25 is not particularly limited, but it is preferable to use a substance and structure having a high transmittance. Thereby, the top emission type organic EL element 1 with high luminous efficiency can be realized. For example, the cathode electrode 25 uses a metal oxide layer made of indium tin oxide (hereinafter referred to as ITO) or indium zinc oxide (hereinafter referred to as IZO). The cathode electrode 25 is not particularly limited to these materials.

  The thin film sealing film 103 is formed on the cathode electrode 25. Specifically, the thin film sealing film 103 is formed on the surface of the cathode electrode 25 and has a function of protecting the element from moisture. Here, since the thin film sealing film 103 is required to be transparent, examples of the material of the thin film sealing film 103 include SiN, SiON, and an organic film.

  The resin sealing layer 104 is formed on the thin film sealing film 103.

  The glass substrate 105 is formed on the resin sealing layer 104.

  The light shielding layer 106 is formed in a light shielding region (first region) other than the region where the organic EL layer 23 is formed.

  The bank layer 30 has a function as a bank (bank) for forming the organic EL layer 23 formed by a wet film formation method in a predetermined region. The material used for the bank layer 30 may be either an inorganic substance or an organic substance, but an organic substance is generally more preferable because it has a higher water repellency. Examples of such materials include resins such as polyimide and polyacryl.

  In the organic EL element 1 configured as described above, when voltage is applied to the light emitting element layer 11B, light is generated in the organic EL layer 23, and light is emitted upward through the cathode electrode 25 and the thin film sealing film 103. Further, light emitted from the organic EL layer 23 directed downward is reflected by the anode electrode 24 as a reflective metal electrode, and light is emitted upward through the cathode electrode 25 and the thin film sealing film 103.

  Note that the drive circuit layer 11A does not necessarily include the planarization insulating film 102. Further, even when the driving circuit layer 11A includes the planarization insulating film 102, it is not always necessary to include a contact hole as long as conduction between the active element and the anode electrode 24 is realized.

  Next, the anode electrode 24 which is a characteristic part of the present invention will be described.

  FIG. 3 is a diagram for explaining a characteristic configuration of the anode electrode according to the first embodiment of the present invention.

  As described above, the anode electrode 24, which is the reflective metal electrode shown in FIG. 3, is composed of at least the transparent metal layer 243 and the reflective metal layer 241, and the transparent metal layer 243 and the reflective metal layer 241 are laminated. One region and a transparent insulating layer 242 has a second region formed between the transparent metal layer 243 and the reflective metal layer 241.

  The reflective metal layer 241 is composed of a metal layer that reflects light, and is formed using a highly reflective metal such as Al, Ag, or an alloy thereof. The reflective metal layer 241 reflects light emitted from the organic EL layer 23 in the second region.

The transparent metal layer 243 is composed of a metal layer that transmits light, and is formed using an inorganic transparent conductive material such as ITO, ZnS, ZTO, IZO, Sb ₂ O ₃ , for example. The transparent metal layer 243 is formed in physical contact with the organic EL layer 23 in the second region.

  The transparent insulating layer 242 is formed using a transparent resin material such as polyimide, polyurethane, or acrylic. The transparent insulating layer 242 is formed at least in the second region, that is, the region where the reflective metal layer 241 reflects light emitted from the organic EL layer 23. The light emitting element layer 11B includes the transparent insulating layer 242, so that the reflective metal layer 241 and the transparent metal layer 243 are not in direct contact with each other in the second region.

  As described above, one of the source / drain electrodes 224 (for example, the source electrode) of the drive transistor 22 is connected to the anode electrode 24 of the organic EL element 1 and the contact hole 102a, that is, the connection opening 25a provided in the planarization insulating film 102. Connected through. Here, even when the aspect ratio of the connection opening 25a is high (that is, the depth is deep), since the reflective metal layer 241 is formed of a metal material, electrical conduction is made to the bottom surface of the connection opening 25a. It is relatively easy to form in a maintained state. Therefore, by forming the contact hole 102a in the planarization insulating film 102, it is possible to stably obtain electrical contact between one of the source / drain electrodes 224 (for example, the source electrode) and the reflective metal layer 241.

  In addition, this inventor (etc.) confirmed that the light extraction efficiency of the organic EL element 1 was improved, and high luminance and low power consumption were possible with the above-described configuration. .

  The following is a discussion of this.

  First, in the configuration of the conventional organic EL element, the low light extraction efficiency is considered to be due to the influence of plasmon generation. That is, when an anode electrode made of only the reflective metal layer 241 is formed using a reflective metal material for the purpose of directly forming the reflective layer on the organic EL layer 23, the light from the organic EL layer 23 is reflected by the reflective metal. More than the light reflected by the layer 241, more light is lost in the reflective metal layer 241 through the formation of surface plasmon-polaritons, resulting in reduced extraction efficiency.

  Further, even when the organic EL layer 23 and the reflective metal layer 241 are sandwiched between the organic EL layer 23 and the reflective metal layer 241, and the organic EL layer 23 and the reflective metal layer 241 are not in direct contact with each other, the extraction efficiency is reduced. It was found that this phenomenon was observed.

  Therefore, as a result of investigations by the inventors of the present application, in order to reduce the formation of surface plasmon-polariton in the reflective metal layer 241, a region where the reflective metal layer 241 reflects light from the organic EL layer 23 ( It has been found that it is effective not to bring the reflective metal layer 241 into electrical contact with the organic EL layer 23 in the second region).

  The present invention is based on the above knowledge, and the anode electrode 24, which is a reflective metal electrode that reflects upward the light generated in the organic EL layer 23, is reflected in the second region. The metal layer 241, the transparent insulating layer 242, and the transparent metal layer 243 are configured, and the first region is configured by the reflective metal layer 241 and the transparent metal layer 243. That is, the transparent insulating layer 242 is formed at least in the second region where the reflective metal layer 241 reflects light emitted from the organic EL layer 23. With this configuration, the reflective metal layer 241 and the transparent metal layer 243 are not in direct electrical contact in the second region.

  With the above configuration, when light is reflected by the anode electrode 24, that is, the reflective metal layer 241, light attenuation due to the influence of plasmon generation can be suppressed, so that the light extraction efficiency is improved and the luminance is increased. Moreover, the organic EL element 1 capable of reducing power consumption can be realized.

  Furthermore, when the organic EL element 1 according to the present embodiment is used for the display device shown in FIG. 4, a display device with high luminance and low power consumption can be realized. Here, FIG. 4 is a figure which shows an example of the display apparatus using the organic EL element of this invention.

(Modification)
FIG. 5 is a cross-sectional view for explaining a main part of the organic EL element in the modification of the first embodiment of the present invention. Elements similar to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The organic EL element 2 shown in FIG. 5 differs from the organic EL element 1 shown in FIG. 1 in the configuration of the connection opening 25 b and the anode electrode 34. Specifically, in the organic EL element 1 shown in FIG. 1, the reflective metal layer 241 is formed in the contact hole 102a provided in the planarization insulating film 102, and the connection opening 25a is configured. On the other hand, in the organic EL element 2 shown in FIG. 5, the reflective metal layer 241 and the transparent metal layer 343 are formed in the contact hole 102a provided in the planarization insulating film 102, and the connection opening 25b is formed. . This is because when the aspect ratio of the contact hole 102a is low (that is, the depth is shallow or the opening diameter is large with respect to the depth), not only the reflective metal layer 241 but also the transparent metal layer 343 is formed. This is because that.

  Since points other than the above-described configuration are the same as those of the organic EL element 1, the description thereof is omitted.

(Embodiment 2)
In the first embodiment, the top emission organic EL element is described as an example. In the second embodiment, a bottom emission organic EL element is described as an example.

  FIG. 6 is a cross-sectional view for explaining a main part of the organic EL element 1 according to Embodiment 1 of the present invention. In FIG. 6, the bottom emission type organic EL element 3 is shown.

  The organic EL element 3 shown in FIG. 6 includes a substrate 300, a drive circuit layer 31A stacked on the substrate 300, and a light emitting element layer 31B stacked on the drive circuit layer 31A.

  The substrate 300 is, for example, a glass substrate, and constitutes a thin film transistor (TFT) in a region (first region) corresponding to the outside of the light emitting region of the light emitting element layer 31B together with the drive circuit layer 31A. In addition, since the organic EL element 3 has a bottom emission type structure, the substrate 300 is required to be transparent. Therefore, examples of the material of the substrate 300 include SiN and SiON.

  The drive circuit layer 31A includes an interlayer insulating film 301 and a planarizing insulating film 302, and in the first region of the interlayer insulating film 301 and the planarizing insulating film 302 (a region corresponding to the outside of the light emitting region of the light emitting element layer 31B). For example, a drive transistor 42 is formed as an active element for driving the light emitting element layer 31B. In the drive circuit layer 31A, a contact hole 302a having a connection opening 45a is formed in the planarization insulating film 302.

  The driving transistor 42 is, for example, a bottom-gate thin film transistor, and includes a gate electrode 421, a gate insulating film 422, a semiconductor layer 423, and a source / drain electrode 424 that are sequentially formed from the substrate 300.

  Here, as a material of each electrode, for example, an alloy of molybdenum (Mo) and tungsten (W) or an alloy of Mo and W / aluminum (Al) / Mo and W is laminated. It is done. Further, as the material of the gate insulating film 422, since the organic EL element 3 has a bottom emission type structure, it is required to be transparent, for example, a silicon oxide film (SiOx) or a silicon nitride film (SiN). Is mentioned. Note that the gate insulating film 422 may be a dielectric material for securing a desired capacitance as long as it is transparent.

  One of the source / drain electrodes 424 (for example, the source electrode) of the driving transistor 42 is connected to the anode electrode 44 constituting the light emitting element layer 31 </ b> B through a connection opening 45 a provided in the planarization insulating film 302. .

  The planarization insulating film 302 corresponds to the planarization insulating layer of the present invention, is formed so as to cover the active element, and planarizes the upper surface of the drive circuit layer. Specifically, the planarization insulating film 302 is formed on the interlayer insulating film 301 so as to cover the drive transistor 42, and planarizes the upper surface of the drive circuit layer 31A. Further, as described above, the planarization insulating film 102 has the contact hole 302a having the connection opening 45a. Then, the source electrode of the drive transistor 42 and the anode electrode 44 of the light emitting element layer 31B are connected through the connection opening 45a. In other words, the planarization insulating layer 320 has a contact hole 302a for electrically connecting the anode electrode 44 and the drive transistor 42 in a region corresponding to the outside of the second region (first region). The anode electrode 44 is also formed in the contact hole 302a. That is, the contact hole 302a is formed in the region of the planarization insulating film 302 corresponding to the outside of the second region (first region), and electrically connects the anode electrode 44 and the drive transistor 42 that is an active element. Note that the materials of the interlayer insulating film 301 and the planarization insulating film 302 are the same as those of the interlayer insulating film 101 and the planarization insulating film 102 in Embodiment 1 except that they are required to be transparent. Description is omitted.

  The light emitting element layer 31 </ b> B includes an organic EL layer 43, an anode electrode 44, a cathode electrode 45, and a pixel isolation insulating layer 46.

  The anode electrode 44 corresponds to the first electrode layer of the present invention and is a transparent electrode formed on the planarization insulating film 302. The anode electrode 44 applies a positive voltage to the light emitting element layer 31 </ b> B with respect to the cathode electrode 45. The material of the anode electrode 44 is not particularly limited, but it is preferable to use a substance and structure having a high transmittance. Thereby, the bottom emission type organic EL element 3 with high luminous efficiency can be realized. For example, the anode electrode 44 is made of a metal oxide layer made of ITO or IZO. The anode electrode 44 is not particularly limited to these materials.

  The cathode electrode 45 is a reflective metal electrode formed so as to cover the organic EL layer 43 and the pixel isolation insulating layer 46. A negative voltage is applied to the organic EL layer 43 with respect to the anode electrode 44, and electrons are supplied. It has a function of injecting into the light emitting element layer 31B (in particular, the organic EL layer 43).

  Specifically, the cathode electrode 45 corresponds to the second electrode layer of the present invention, and includes at least a transparent metal layer 453 that is a metal layer that transmits light and a reflective metal layer 451 that is a metal layer that reflects light. The first region where the transparent metal layer 453 and the reflective metal layer 451 are laminated and the transparent insulating layer 452 that is an insulating layer that transmits light are formed between the transparent metal layer 453 and the reflective metal layer 451. A second region. The reflective metal layer 451 reflects light emitted from the organic EL layer 43 in the second region. In addition, about the material of the transparent insulating layer 452, the transparent metal layer 453, and the reflective metal layer 451, and the effect at the time of providing these, the transparent insulating layer 242, the transparent metal layer 243, and the reflective metal layer 241 of Embodiment 1 are mentioned. The description is omitted because it is the same as.

  The organic EL layer 43 corresponds to the organic EL layer of the present invention, and is formed between the first electrode layer and the second electrode layer in contact with the transparent metal layer 453 in the second region, with the first electrode layer interposed therebetween. Emits the emitted light. Specifically, the organic EL layer 43 is formed under a partial region (second region) of the cathode electrode 45, and holes and electrons are injected from the anode electrode 44 and the cathode electrode 45 to recombine. As a result, an excited state is generated and light is emitted. The configuration and material of the organic EL layer 43 are the same as those of the organic EL layer 23 of the first embodiment, and thus description thereof is omitted.

  In the organic EL element 3 configured as described above, when voltage is applied to the light emitting element layer 31B, light is generated in the organic EL layer 43, and the anode electrode 44, the planarization insulating film 302, the interlayer insulating film 301, and the gate insulating film. Light is emitted downward through 422 and the substrate 300. Further, the light generated in the organic EL layer 43 that is directed upward is reflected by the cathode electrode 45 as a reflective metal electrode, and the anode electrode 44, the planarization insulating film 302, the interlayer insulating film 301, and the gate insulating film. Light is emitted downward through 422 and the substrate 300.

  As described above, in the organic EL element 3 of the present embodiment, the transparent insulating layer 452 is formed at least in the second region where the reflective metal layer 451 reflects light emitted from the organic EL layer 43. With this configuration, the reflective metal layer 451 and the transparent metal layer 453 are not in direct electrical contact in the second region.

  With the above structure, light attenuation due to the influence of plasmon generation can be suppressed when light is reflected by the reflective metal layer 451, so that light extraction efficiency is improved, high luminance and low power consumption are achieved. The organic EL element 1 that can be realized can be realized.

  Furthermore, when the organic EL element 1 according to the present embodiment is used for the display device shown in FIG. 4, a display device with high luminance and low power consumption can be realized.

  Note that the drive circuit layer 31A does not necessarily include the planarization insulating film 302. In addition, even when the drive circuit layer 31A includes the planarization insulating film 302, it is not always necessary to include a contact hole as long as conduction between the active element and the anode electrode 44 is realized.

  As mentioned above, although the organic electroluminescent element of this invention and the display apparatus using the same were demonstrated based on embodiment, this invention is not limited to this embodiment. Unless it deviates from the meaning of this invention, the form which carried out the various deformation | transformation which those skilled in the art can think to this embodiment, and the structure constructed | assembled combining the component in different embodiment is also contained in the scope of the present invention. .

  INDUSTRIAL APPLICABILITY The present invention can be used for an organic electroluminescence element and a display device using the same, and in particular, can be used for an organic electroluminescence element realizing high luminance and low power consumption and a display device using the same.

1, 2, 3 Organic EL element 11A, 31A Drive circuit layer 11B, 31B Light emitting element layer 21 Select transistor 22, 42 Drive transistor 23, 43 Organic EL layer 24, 34, 44 Anode electrode 25, 45 Cathode electrode 25a, 25b, 45a connection opening 30 bank layer 46 pixel isolation insulating layer 100, 300 substrate 101, 301 interlayer insulating film 102, 302 planarization insulating film 102a, 302a contact hole 103 thin film sealing film 104 resin sealing layer 105 glass substrate 106 light shielding layer 211 221, 421 Gate electrode 212, 422 Gate insulating film 213, 223, 423 Semiconductor layer 214, 224, 424 Source / drain electrode 231 Hole injection layer 232 Hole transport layer 233 Organic light emitting layer 234 Electron transport layer 235 Electron injection layer 241 45 Reflective metal layer 242,452 transparent insulating layer 243,343,453 transparent metal layer

Claims (8)

A first electrode layer that is a transparent electrode;
A first region comprising at least a transparent metal layer that is a metal layer that transmits light and a reflective metal layer that is a metal layer that reflects light, wherein the transparent metal layer and the reflective metal layer are stacked; and A second electrode layer having a transparent insulating layer that is a transparent insulating layer and a second region formed between the transparent metal layer and the reflective metal layer;
An organic EL (Electro Luminescence) layer that is formed between the first electrode layer and the second electrode layer and emits light emitted through the first electrode layer;
The organic EL layer is formed in contact with the transparent metal layer in the second region,
The reflective metal layer is an organic electroluminescence element that reflects light emitted from the organic EL layer in the second region. The organic electroluminescence element is
A substrate,
A driving circuit layer having an active element for driving the organic EL layer on the substrate;
The organic electroluminescence element according to claim 1, wherein the first electrode layer, the organic EL layer, and the second electrode layer are formed on the drive circuit layer. The drive circuit layer includes
A planarization insulating layer that covers the active element and planarizes the upper surface of the drive circuit layer;
The organic electroluminescence element according to claim 2, wherein the first electrode layer, the organic EL layer, and the second electrode layer are formed on the planarization insulating layer. The second electrode layer is formed on the driving circuit layer,
The organic EL layer is formed on the second electrode layer,
The organic electroluminescence element according to claim 2, wherein the first electrode layer is formed on the organic EL layer. The planarization insulating layer has a contact hole for electrically connecting the transparent metal layer and the active element in a region corresponding to the outside of the second region,
The organic electroluminescence element according to claim 4, wherein the reflective metal layer is also formed in the contact hole. In the drive circuit layer, the active element is formed in a region corresponding to the outside of the second region,
The first electrode layer is formed on the driving circuit layer,
The organic EL layer is formed on the first electrode layer,
The organic electroluminescence element according to claim 2, wherein the second electrode layer is formed on the organic EL layer. The planarization insulating layer has a contact hole for electrically connecting the first electrode layer and the active element in a region corresponding to the outside of the second region,
The organic electroluminescence element according to claim 4, wherein the first electrode layer is also formed in the contact hole. A display device comprising the organic electroluminescence element according to claim 1.

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