DISPLAY DEVICE

According to one embodiment, a display device includes a switching element, a first insulating layer including a first contact hole penetrating to the switching element, a conductive material filled in the first contact hole, a lower electrode arranged above the first insulating layer and being in contact with the conductive material, an organic layer stacked on the lower electrode, and including a hole injection layer on the lower electrode, a hole transport layer on the hole injection layer, and a light emitting layer on the hole transport layer, an upper electrode stacked on the organic layer, and a coating layer covering an end surface of each of the lower electrode, the hole injection layer, and the hole transport layer.

FIELD

BACKGROUND

Recently, display devices with organic light-emitting diodes (OLEDs) applied thereto as display elements have been put into practical use. Such a display element comprises an organic layer between a pixel electrode and a common electrode. The organic layer includes functional layers such as a hole transport layer and an electron transport layer in addition to a light emitting layer. Increasing the area that contributes to display (light emission) in such a display element is requested.

DETAILED DESCRIPTION

Embodiments described herein aim to provide a display device capable of increasing an area contributing to display.

In general, according to one embodiment, a display device comprises a substrate, a switching element arranged above the substrate, a first insulating layer arranged above the substrate and including a first contact hole penetrating to the switching element, a conductive material filled in the first contact hole, a lower electrode arranged above the first insulating layer and being in contact with the conductive material, an organic layer stacked on the lower electrode and including a hole injection layer on the lower electrode, a hole transport layer on the hole injection layer, and a light emitting layer on the hole transport layer, an upper electrode stacked on the organic layer, and a coating layer covering an end surface of each of the lower electrode, the hole injection layer, and the hole transport layer.

According to another embodiment, a display device comprises a substrate, a switching element arranged above the substrate, a first insulating layer arranged above the substrate and including a first contact hole penetrating to the switching element, a conductive material filled in the first contact hole, a lower electrode arranged above the first insulating layer and being in contact with the conductive material, an organic layer including a light emitting layer, and stacked on the lower electrode, an upper electrode stacked on the organic layer, and a coating layer covering an end surface of the lower electrode.

According to yet another embodiment, a display device comprises a substrate, a switching element arranged above the substrate, a first insulating layer arranged above the substrate and including a first contact hole penetrating to the switching element, a conductive material filled in the first contact hole, a lower electrode arranged above the first insulating layer and being in contact with the conductive material, an organic layer including a light emitting layer, stacked on the lower electrode, and covering an end surface of the lower electrode, and an upper electrode stacked on the organic layer and covering an end surface of the organic layer.

According to the embodiments, a display device capable of increasing an area contributing to display can be provided.

The disclosure is merely an example, and proper changes within the spirit of the invention, which are easily conceivable by a person of ordinary skill in the art, are included in the scope of the invention as a matter of course. In addition, in order to make the description clearer, the widths, thicknesses, shapes and the like, of the respective parts are schematically illustrated in the drawings, compared to the actual modes, in some cases. However, the schematic illustration is merely an example, and adds no restriction to the interpretation of the invention. In addition, in the specification and drawings, structural elements which function in the same or a similar manner to those described in connection with preceding drawings are denoted by like reference numbers, detailed description thereof being omitted unless necessary.

In the figures, an X-axis, a Y-axis and a Z-axis orthogonal to each other are described to facilitate understanding as needed. A direction along the X-axis is referred to as an X-direction or a first direction, a direction along the Y-axis is referred to as a Y-direction or a second direction, and a direction along the Z-axis is referred to as a Z-direction or a third direction. A plane defined by the X-axis and the Y-axis is referred to as an X-Y plane. Viewing the X-Y plane is referred to as plan view.

The display device DSP according to the embodiment is an organic electroluminescent display device comprising organic light emitting diodes (OLED) as display elements, and is mounted on televisions, personal computers, mobile terminals, mobile phones, and the like. The display element described below can be applied as a light emitting element of an illumination device, and the display device DSP can be applied to other electronic devices such as an illumination device.

FIG.1is a view showing a configuration example of the display device DSP according to the embodiments. The display device DSP comprises a display portion DA where images are displayed, on an insulating substrate10. The substrate10may be glass or a flexible resin film.

The display portion DA comprises a plurality of pixels PX arrayed in a matrix in the first direction X and the second direction Y. The pixel PX comprises a plurality of sub-pixels SP1, SP2, and SP3. As an example, the pixel PX comprises a red sub-pixel SP1, a green sub-pixel SP2, and a blue sub-pixel SP3. In addition to the sub-pixels of the above three colors, the pixel PX may comprise four or more sub-pixels including a sub-pixel of the other color such as white.

A configuration example of one sub-pixel SP included in the pixel PX will be described simply.

In other words, the sub-pixel SP comprises a pixel circuit1and a display element20driven by the pixel circuit1. The pixel circuit1comprises a pixel switch2, a drive transistor3, and a capacitor4. The pixel switch2and the drive transistor3are, for example, switch elements constituted by thin-film transistors.

In the pixel switch2, a gate electrode is connected to a scanning line GL, a source electrode is connected to a signal line SL, and a drain electrode is connected to one of electrodes constituting the capacitor4and a gate electrode of the drive transistor3. In the drive transistor3, a source electrode is connected to the other electrode constituting the capacitor4and a power line PL, and a drain electrode is connected to an anode of the display element20. A cathode of the display element20is connected to a power supply line FL. The configuration of the pixel circuit1is not limited to the example shown in the figure.

The display element20is an organic light emitting diode (OLED) which is a light emitting element. For example, the sub-pixel SP1comprises a display element that emits light corresponding to a red wavelength, the sub-pixel SP2comprises a display element that emits light corresponding to a green wavelength, and the sub-pixel SP3comprises a display element that emits light corresponding to a blue wavelength. The pixel PX can realize multicolor display by comprising a plurality of sub-pixels SP1, SP2, and SP3of different display colors.

However, the pixel PX may also be configured such that the display element20of each of the sub-pixels SP1, SP2, and SP3emits light of the same color. Monochromatic display can be thereby realized.

In addition, when the display element20of each of the sub-pixels SP1, SP2, and SP3is configured to emit white light, a color filter opposed to the display element20may be arranged. For example, the sub-pixel SP1may comprise a red color filter opposed to the display element20, the sub-pixel SP2may comprise a green color filter opposed to the display element20, and the sub-pixel SP3may comprise a blue color filter opposed to the display element20. Multicolor display can be thereby realized.

Alternatively, when the display element20of each of the sub-pixels SP1, SP2, and SP3is configured to emit ultraviolet light, multicolor display can be realized by arranging a light conversion layer opposed to the display element20.

FIG.2is a view showing an example of a configuration of the display element20.

The display element20comprises a lower electrode (first electrode) E1, an organic layer OR, and an upper electrode (second electrode) E2. The organic layer OR includes a carrier adjustment layer (first carrier adjustment layer) CA1, a light emitting layer EL, and a carrier adjustment layer (second carrier adjustment layer) CA2. The carrier adjustment layer CA1is located between the lower electrode E1and the light emitting layer EL, and the carrier adjustment layer CA2is located between the light emitting layer EL and the upper electrode E2. The carrier adjustment layers CA1and CA2include a plurality of functional layers.

An example in which the lower electrode E1corresponds to an anode and the upper electrode E2corresponds to a cathode will be described.

The carrier adjustment layer CA1includes a hole injection layer F11, a hole transport layer F12, an electron blocking layer F13, and the like, as functional layers. The hole injection layer F11is arranged on the lower electrode E1, the hole transport layer F12is arranged on the hole injection layer F11, the electron blocking layer F13is arranged on the hole transport layer F12, and the light emitting layer EL is arranged on the electron blocking layer F13.

The carrier adjustment layer CA2includes a hole blocking layer F21, an electron transport layer F22, an electron injection layer F23, and the like, as functional layers. The hole blocking layer F21is arranged on the light emitting layer EL, the electron transport layer F22is arranged on the hole blocking layer F21, the electron injection layer F23is arranged on the electron transport layer F22, and the upper electrode E2is arranged on the electron injection layer F23.

In addition to the functional layers described above, the carrier adjustment layers CA1and CA2may also include the other functional layers such as a carrier generation layer as needed or at least one of the above functional layers may be omitted in the carrier adjustment layers CA1and CA2.

FIG.3is a cross-sectional view showing a basic structure of the display device DSP.

The pixel circuit1shown inFIG.1is arranged above the substrate10. InFIG.3, only a drive transistor (switching element)3included in the pixel circuit1is simplified and shown.

The insulating layer (first insulating layer)11is arranged above the substrate10and corresponds to an underlying layer of the display element20. The insulating layer11is, for example, an organic insulating layer. The insulating layer11includes a contact hole (first contact hole) CH1that penetrates to the drive transistor3. A conductive material CD is filled in the contact hole CH1and is in contact with the drive transistor3. The conductive material CD is formed of, for example, a material containing metals such as titanium (Ti), molybdenum (Mo), tungsten (W), magnesium (Mg), silver (Ag), and tantalum (Ta).

The display element20comprises a lower electrode E1, an organic layer OR, and an upper electrode E2.

The lower electrodes E1of the respective display elements20are arranged at intervals in the first direction X, and each of them is arranged on the insulating layer11. Each of the lower electrodes E1is in contact with the conductive material CD and is electrically connected to the drive transistor3. The lower electrode E1is an electrode arranged for each sub-pixel or each display element and is referred to as a pixel electrode, an anode or the like in some cases.

The lower electrode E1is, for example, a transparent electrode formed of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The lower electrode E1may be a metal electrode formed of a metal material such as silver or aluminum. Alternatively, the lower electrode E1may be a stacked layer body of transparent electrodes and metal electrodes. For example, the lower electrode E1may be constituted as a stacked layer body formed by stacking a transparent electrode, a metal electrode, and a transparent electrode, in this order, or may be constituted as a stacked layer body of three or more layers. In this case, the transparent electrode containing a conductive material different from the conductive material CD, of the lower electrode E1, is in contact with the conductive material CD. However, the electrode of the same material as the conductive material CD, of the lower electrode E1, may be in contact with the conductive material CD.

The organic layer OR includes a light emitting layer EL as shown inFIG.2. The organic layers OR of the display elements20are stacked on the lower electrodes E11, respectively, and separated from each other. The organic layers OR of the respective display elements20arranged in the first direction X may include the light emitting layers EL formed of materials different from each other (the organic layers OR in the respective display elements20may emit light of different colors) or may include the light emitting layers EL formed of the same material (the organic layers OR in the respective display elements20may emit light of the same color).

The upper electrodes E2of the display elements20are stacked on the organic layers OR, respectively, and are separated from each other. The upper electrodes E2stacked on the organic layers OR arranged in the second direction Y may be formed integrally. The upper electrode E2is electrically connected to the power supply line inside the display portion DA or outside the display portion DA, which will be described later. The upper electrode E2is referred to as a common electrode, a counter-electrode, a cathode or the like in some cases.

The upper electrode E2is, for example, a transflective metal electrode formed of a metal material such as magnesium and silver. The upper electrode E2may be a transparent electrode formed of a transparent conductive material such as ITO or IZO. Alternatively, the upper electrode E2may be a stacked layer body of transparent electrodes and metal electrodes.

A substantially entire body of the organic layer OR is located between the lower electrode E1and the upper electrode E2, and can form a light emission area of the display element20. In one example, a thickness of the organic layer OR along the third direction Z is set such that a peak wavelength of the emission spectrum in the light emitting layer EL matches an effective optical path length between the lower electrode E1and the upper electrode E2. A microcavity structure for obtaining a resonance effect is thereby realized.

In the example shown inFIG.3, an end surface SS1of the lower electrode E1is exposed from the organic layer OR and the upper electrode E2. An end surface SS2of the organic layer OR is located on the lower electrode E1and is exposed from the upper electrode E2. An end surface SS3of the upper electrode E2is located on the organic layer OR.

A sealing layer30covers each display element20. In other words, the sealing layer30covers each of the end surface SS1of the lower electrode E1, the end surface SS2of the organic layer OR, and the end surface SS3and the upper surface U2of the upper electrode E2. In addition, the sealing layer30is in contact with the insulating layer11at a position between the adjacent display elements20. The sealing layer30is, for example, a stacked layer body of inorganic insulating films and organic insulating films. Such a sealing layer30comprises a function of protecting each display element20from moisture and the like.

According to such a display device DSP, a substantially entire body of the organic layer OR can be formed as the light emission area of the display element20, and the area contributing to the display or light emission (area of the light emission area) can be increased, as compared with a configuration in which a rib covering the peripheral part of the lower electrode E1is provided. In addition, undesired light emission in an area different from the predetermined light emission area is suppressed, and degradation of the color purity can be suppressed.

FIG.4is a cross-sectional view showing a first structural example of the display device DSP.

The first structural example shown inFIG.4is different from the basic structure shown inFIG.3in that the organic layer OR covers the end surface SS1of the lower electrode E1. The organic layer OR is in contact with the insulating layer11outside the lower electrode E1. The upper electrode E2is stacked on the organic layer OR to cover the end surface SS2of the organic layer OR. The upper electrode E2is in contact with the insulating layer11outside the organic layer OR. The upper electrodes E2of the respective display elements20arranged in the first direction X are separated from each other.

The sealing layer30covers the upper electrodes E2. In other words, the sealing layer30is in contact with the end surfaces SS3of the upper electrodes E2. In addition, the sealing layer30is in contact with the insulating layer11between the adjacent display elements20.

According to such a first structural example, the same advantages as those of the above-described basic structure can be obtained. In addition, since the organic layer OR covers the end surface SS1of the lower electrode E1, a short circuit between the lower electrode E1and the upper electrode E2can be suppressed.

FIG.5is a cross-sectional view showing a second structural example of the display device DSP.

The second structural example shown inFIG.5is different from the first structural example shown inFIG.4in that the upper electrode E2of each of the display elements20arranged in the first direction X is formed integrally. The upper electrode E2covers the end surface SS2of each of the organic layers OR arranged in the first direction X. The upper electrode E2is in contact with the insulating layer11between the organic layers OR arranged in the first direction X.

The sealing layer30is stacked on the upper electrode E2and is separated from the insulating layer11.

In such a second structural example, the same advantages as those of the first configuration example can also be obtained.

Next, an example of the display element20based on the concepts of the first structural example and the second structural example will be described. Illustration of layers under the insulating layer11is omitted.

FIG.6is a cross-sectional view showing a first example of the display element20.

The hole injection layer F11covers an entire body of the lower electrode E1, the hole transport layer F12covers an entire body of the hole injection layer F11, the electron blocking layer F13covers an entire body of the hole transport layer F12, and the light emitting layer EL covers an entire body of the electron blocking layer F13. The expression “covering an entire body” means covering an upper surface and an end surface (side surface) of a member.

The hole blocking layer F21covers an entire body of the light emitting layer EL, the electron transport layer F22covers an entire body of the hole blocking layer F21, the electron injection layer F23covers an entire body of the electron transport layer F22, and the upper electrode E2covers an entire body of the electron injection layer F23.

A light extraction layer (also referred to as an optical adjustment layer)40for improving a light extraction efficiency from the display element20covers an entire body of the upper electrode E2. The sealing layer30covers an entire body of the light extraction layer40. Each of the layers constituting the organic layer OR, the upper electrode E2, the light extraction layer40, and the sealing layer30is in contact with the insulating layer11.

According to such a first example, the upper electrode E2is in contact with the electron injection layer F23located in the uppermost layer of the organic layer OR, but is not in contact with the other functional layers constituting the organic layer OR or the light emitting layer EL. For this reason, undesired current leakage at the peripheral part of the organic layer OR and the like are suppressed, and the degradation in the performance of the display element20can be suppressed.

FIG.7is a cross-sectional view showing a second example of the display element20.

The second example shown inFIG.7is different from the first example shown inFIG.6in that the light extraction layer40is formed integrally over the adjacent display elements20. In other words, the light extraction layer40covers the adjacent upper electrodes E2and is in contact with the insulating layer11between the adjacent upper electrodes E2. The sealing layer30is stacked on the light extraction layer40and is separated from the insulating layer11.

FIG.8is a cross-sectional view showing a third example of the display element20.

The third example shown inFIG.8is different from the first example shown inFIG.6in that the upper electrode E2is formed integrally over the adjacent display elements20. In other words, the upper electrode E2covers the adjacent electron injection layers F23and is in contact with the insulating layer11between the adjacent electron injection layers F23. The sealing layer30and the light extraction layer40are separated from the insulating layer11.

FIG.9is a cross-sectional view showing a fourth example of the display element20.

The fourth example shown inFIG.9is different from the first example shown inFIG.6in that the electron injection layer F23is formed integrally over the adjacent display elements20. In other words, the electron injection layer F23covers the adjacent electron transport layers F22and is in contact with the insulating layer11between the adjacent electron transport layers F22. The sealing layer30, the light extraction layer40, and the upper electrode E2are separated from the insulating layer11.

FIG.10is a cross-sectional view showing a fifth example of the display element20.

The fifth example shown inFIG.10is different from the first example shown inFIG.6in that the electron transport layer F22is formed integrally over the adjacent display elements20. In other words, the electron transport layer F22covers the adjacent hole blocking layers F21and is in contact with the insulating layer11between the adjacent hole blocking layers F21. The sealing layer30, the light extraction layer40, the upper electrode E2, and the electron injection layer F23are separated from the insulating layer11.

FIG.11is a cross-sectional view showing a sixth example of the display element20.

The sixth example shown inFIG.11is different from the first example shown inFIG.6in that the hole blocking layer F21is formed integrally over the adjacent display elements20. In other words, the hole blocking layer F21covers the adjacent light emitting layers EL and is in contact with the insulating layer11between the adjacent light emitting layers EL. The sealing layer30, the light extraction layer40, the upper electrode E2, the electron injection layer F23, and the electron transport layer F22are separated from the insulating layer11.

In the second to sixth examples, too, the same advantages as those of the first example can be obtained.

FIG.12Ais a cross-sectional view showing a third structural example of the display device DSP.

The third structural example shown inFIG.12Ais different from the basic structure shown inFIG.3in that a coating layer50which covers the end surface SS1of the lower electrode E1is provided. The coating layer50is an insulator and may be formed of an inorganic material or may be formed of an organic material. In addition, the coating layer50may be formed using at least one of the electron blocking layer F13which blocks movement of electrons from the cathode side to the anode side, and the hole blocking layer F21which blocks movement of a hole from the anode side to the cathode side, which will be described later.

The coating layer50is provided independently for each of the lower electrode E1arranged in the first direction X. In other words, the coating layer50provided to correspond to one of the lower electrode E1, of two lower electrodes E1arranged in the first direction X, is separated from the coating layer50provided to correspond to the other lower electrode E1. The insulating layer11is exposed between the adjacent coating layers50.

From the viewpoint of increasing the area of the light emission area as much as possible, an area covered with the coating layer50, of the upper surface U1of the lower electrode E1, is desirably as small as possible.

The sealing layer30covers the upper electrode E2and the organic layer OR of each of the display elements20arranged in the first direction X, and also covers the coating layer50. In addition, the sealing layer30is in contact with the insulating layer11between the coating layers50arranged in the first direction X.

According to such a third structural example, the same advantages as those of the above-described basic structure can be obtained. In addition, since the coating layer50covers the end surface SS1of the lower electrode E1, a short circuit between the lower electrode E1and the upper electrode E2can be suppressed.

FIG.12Bis a cross-sectional view showing a fourth structural example of the display device DSP.

The fourth structural example shown inFIG.12Bis different from the third structural example shown inFIG.12Ain that the upper electrode E2of each of the display elements20arranged in the first direction X is formed integrally. The upper electrode E2covers the organic layer OR of each of the display elements20arranged in the first direction X, and also covers the coating layer50. In addition, the upper electrode E2is in contact with the insulating layer11between the coating layers50arranged in the first direction X.

The sealing layer30is stacked on the upper electrode E2and is separated from the insulating layer11.

In such a fourth structural example, the same advantages as those of the third structural example can also be obtained.

FIG.13Ais a cross-sectional view showing a fifth structural example of the display device DSP.

The fifth structural example shown inFIG.13Ais different from the third structural example shown inFIG.12Ain that the coating layer50covers the end surface SS1of the lower electrode E1and the end surface SS2of the organic layer OR. The insulating layer11is exposed between the adjacent coating layers50.

The sealing layer30covers the upper electrode E2of each of the display elements20arranged in the first direction X, and also covers the coating layer50. In addition, the sealing layer30is in contact with the insulating layer11between the coating layers50arranged in the first direction X.

In such a fifth structural example, the same advantages as those of the third structural example can also be obtained. In addition, since the coating layer50covers an end surface of each layer constituting the organic layer OR, undesired current leakage at the peripheral part of the organic layer OR and the like are suppressed, and the degradation in the performance of the display element20can be suppressed.

FIG.13Bis a cross-sectional view showing a sixth structural example of the display device DSP.

The sixth structural example shown inFIG.13Bis different from the fifth structural example shown inFIG.13Ain that the upper electrode E2of each of the display elements20arranged in the first direction X is formed integrally. The upper electrode E2covers the organic layer OR of each of the display elements20arranged in the first direction X, and also covers the coating layer50. In addition, the upper electrode E2is in contact with the insulating layer11between the coating layers50arranged in the first direction X.

The sealing layer30is stacked on the upper electrode E2and is separated from the insulating layer11.

In such a sixth structural example, the same advantages as those of the fifth structural example can also be obtained.

FIG.14Ais a cross-sectional view showing a seventh structural example of the display device DSP.

The seventh structural example shown inFIG.14Ais different from the third structural example shown inFIG.12Ain that the coating layer50which covers each of the end surfaces SS1of the adjacent lower electrodes E1is formed integrally. The insulating layer11is covered with the coating layer50between the adjacent lower electrodes E1.

The sealing layer30covers the upper electrode E2of each of the display elements20arranged in the first direction X, and also covers the coating layer50.

In such a seventh structural example, the same advantages as those of the third structural example can also be obtained.

FIG.14Bis a cross-sectional view showing an eighth structural example of the display device DSP.

The eighth structural example shown inFIG.14Bis different from the seventh structural example shown inFIG.14Ain that the upper electrode E2of each of the display elements20arranged in the first direction X is formed integrally. The upper electrode E2covers the organic layer OR of each of the display elements20arranged in the first direction X, and also covers the coating layer50. The upper electrode E2and the sealing layer30are separated from the insulating layer11between the display elements20arranged in the first direction X.

In such an eighth structural example, the same advantages as those of the third structural example can also be obtained.

FIG.15Ais a cross-sectional view showing a ninth structural example of the display device DSP.

The ninth structural example shown inFIG.15Ais different from the seventh structural example shown inFIG.14Ain that the coating layer50covers the end surface SS1of the lower electrode E1and the end surface SS2of the organic layer OR. The insulating layer11is covered with the coating layer50between the adjacent lower electrodes E1.

The sealing layer30covers the upper electrode E2of each of the display elements20arranged in the first direction X, and also covers the coating layer50.

In such a ninth structural example, the same advantages as those of the third structural example can also be obtained.

FIG.15Bis a cross-sectional view showing a tenth structural example of the display device DSP.

The tenth structural example shown inFIG.15Bis different from the ninth structural example shown inFIG.15Ain that the upper electrode E2of each of the display elements20arranged in the first direction X is formed integrally. The upper electrode E2covers the organic layer OR of each of the display elements20arranged in the first direction X, and also covers the coating layer50. The upper electrode E2and the sealing layer30are separated from the insulating layer11between the display elements20arranged in the first direction X.

In such a tenth structural example, the same advantages as those of the third structural example can also be obtained.

Next, an example of the display element20based on the concepts of the third structural example, the fourth structural example, the fifth structural example, the sixth structural example, the seventh structural example, the eighth structural example, the ninth structural example, and the tenth structural example will be described. Illustration of layers under the insulating layer11is omitted.

FIG.16is a cross-sectional view showing a seventh example of the display element20.

An end surface SS11of the hole injection layer F11is located on the lower electrode E1. An end surface SS12of the hole transport layer F12is located on the hole injection layer F11. The coating layer50covers the end surface SS1of the lower electrode E1, the end surface SS11of the hole injection layer F11, and the end surface SS12of the hole transport layer F12.

An end surface SS13of the electron blocking layer F13is located on the coating layer50. An end surface SSEL of the light emitting layer EL is located on the electron blocking layer F13. Illustration of the layers above the light emitting layer EL is omitted, but each of the layers constituting the organic layer OR is formed such that area of upper layers is smaller than area of lower layers. In other words, each of the layers constituting the display element20is formed such that upper layers have smaller area.

FIG.17is a cross-sectional view showing an eighth example of the display element20.

The eighth example shown inFIG.17is different from the seventh example shown inFIG.16in that the coating layer50covers an end surface SS13of the electron blocking layer F13in addition to the end surface SS1, the end surface SS11, and the end surface SS12. The end surface SSEL of the light emitting layer EL is located on the coating layer50.

FIG.18is a cross-sectional view showing a ninth example of the display element20.

The ninth example shown inFIG.18is different from the eighth example shown inFIG.17in that the coating layer50covers the end surface SSEL of the light emitting layer EL in addition to the end surface SS1, the end surface SS11, the end surface SS12, and the end surface SS13. The end surface SSEL is located on the electron blocking layer F13.

FIG.19is a cross-sectional view showing a tenth example of the display element20.

The tenth example shown inFIG.19is different from the ninth example shown inFIG.18in that the coating layer50covers an end surface SS21of the hole blocking layer F21in addition to the end surface SS1, the end surface SS11, the end surface SS12, the end surface SS13, and the end surface SSEL. The end surface SS21is located on the light emitting layer EL. Illustration of the layers above the hole blocking layer F21is omitted.

FIG.20is a cross-sectional view showing an eleventh example of the display element20.

The eleventh example shown inFIG.20is different from the tenth example shown inFIG.19in that the coating layer50covers an end surface SS22of the electron transport layer F22in addition to the end surface SS1, the end surface SS11, the end surface SS12, the end surface SS13, the end surface SSEL, and the end surface SS21. The end surface SS22is located on the hole blocking layer F21. Illustration of the layers above the electron transport layer F22is omitted.

FIG.21is a cross-sectional view showing a twelfth example of the display element20.

The twelfth example shown inFIG.21is different from the eleventh example shown inFIG.20in that the coating layer50covers an end surface SS23of the electron injection layer F23in addition to the end surface SS1, and the end surface SS11, the end surface SS12, the end surface SS13, the end surface SSEL, the end surface SS21, and the end surface SS22. The end surface SS23is located on the electron transport layer F22. Illustration of the layers above the electron injection layer F23is omitted.

FIG.22is a cross-sectional view showing a thirteenth example of the display element20.

The thirteenth example shown inFIG.22corresponds to an example in which that the electron blocking layer F13constitutes the coating layer50. In other words, the electron blocking layer F13covers the lower electrode E1including the end surface SS1, the hole injection layer F11including the end surface SS11, and the hole transport layer F12including the end surface SS12. The light emitting layer EL is located on the electron blocking layer F13. The electron blocking layer F13is in contact with the insulating layer11outside the lower electrode E1. Illustration of the layers above the light emitting layer EL is omitted.

FIG.23is a cross-sectional view showing a fourteenth example of the display element20.

The fourteenth example shown inFIG.23corresponds to an example in which that the hole blocking layer F21constitutes the coating layer50. In other words, the hole blocking layer F21covers the lower electrode E1including the end surface SS1, the hole injection layer F11including the end surface SS11, the hole transport layer F12including the end surface SS12, the electron blocking layer F13including the end surface SS13, and the light emitting layer EL including the end surface SSEL. The hole blocking layer F21is in contact with the insulating layer11outside the lower electrode E1. Illustration of the layers above the hole blocking layer F21is omitted.

FIG.24is a cross-sectional view showing a fifteenth example of the display element20.

The fifteenth example shown inFIG.24corresponds to an example in which that the electron blocking layer F13and the hole blocking layer F21constitute the coating layer50. In other words, the electron blocking layer F13covers the lower electrode E1including the end surface SS1, the hole injection layer F11including the end surface SS11, and the hole transport layer F12including the end surface SS12. The light emitting layer EL is located on the electron blocking layer F13. The hole blocking layer F21covers the electron blocking layer F13, and the light emitting layer EL including the end surface SSEL. The electron blocking layer F13is in contact with the insulating layer11outside the lower electrode E1. The hole blocking layer F21is in contact with the insulating layer11outside the electron blocking layer F13. Illustration of the layers above the hole blocking layer F21is omitted.

In the above-described display element20, the position and the shape of the contact hole CH1(or the conductive material CD) for connecting the lower electrode E1with the drive transistor3are not particularly limited.

FIG.25is a schematic plan view showing the display element20.

In an example shown on the left side of the drawing, the contact hole CH1is formed in a substantially circular shape, and the conductive material CD is filled in the contact hole CH1. In an example shown on the right side of the drawing, the contact hole CH1is formed in a substantially elliptic shape or oval shape, and the conductive material CD is filled in the contact hole CH1.

The position of the contact hole CH1may be any position if the position is a position overlapping the lower electrode E1in plan view. In addition, the shape of the contact hole CH1may be a polygon such as a quadrangle. In addition, in plan view, a rate of area of the contact hole CH1to area of the lower electrode E1is minute in the example shown inFIG.25, but the rate may be larger, for example, 50% or more and less than 100%.

FIG.26is a cross-sectional view illustrating an example of a boundary surface BR between the conductive material CD and the lower electrode E1.

In the example shown inFIG.26, the boundary surface BR is located below an upper surface U11of the insulating layer11. In other words, the conductive material CD is not filled to an upper end represented by a dotted line, in the contact hole CH1. The lower electrode E1is arranged in the contact hole CH1and is formed along an inclined surface of the insulating layer11. For this reason, the lower electrode E1has a recessed upper surface U1. The organic layer OR is arranged on the upper surface U1. The upper electrode E2is arranged on the organic layer OR.

According to such a display element20, since light is emitted in a direction indicated by an arrow of a dotted line, the viewing angle can be extended.

FIG.27is a cross-sectional view illustrating another example of the boundary surface BR between the conductive material CD and the lower electrode E1.

In the example shown inFIG.27, the boundary surface BR is located above the upper surface U11of the insulating layer11. In other words, the conductive material CD is filled over the upper end represented by a dotted line, in the contact hole CH1. For this reason, the boundary surface BR is formed in an upwardly protruding shape. The lower electrode E1has a protruding upper surface U1. The organic layer OR is arranged on the upper surface U1. The upper electrode E2is arranged on the organic layer OR.

In such a display element20, since light is emitted in a direction indicated by an arrow of a dotted line, the viewing angle can also be extended.

FIG.28is a plan view showing a configuration example of the upper electrodes E2.

At the display portion DA, the red sub-pixels SP1, the green sub-pixels SP2, and the blue sub-pixels SP3are arranged in the first direction X. A plurality of sub-pixels of the same color are arranged in the second direction Y.

Each of a plurality of upper electrodes E2is formed in a strip shape extending in the second direction Y, and the upper electrodes E2are arranged at intervals in the first direction X. Each of the upper electrodes E2is arranged at the display portion DA to extend to the outside of the display portion DA. One upper electrode E2is arranged over the sub-pixels of the same color arranged in the second direction Y.

A plurality of power supply lines FL are arranged outside the display portion DA, and overlap the upper electrodes E2, respectively, in plan view. In the contact holes CH2, the upper electrodes E2are in contact with the power supply lines FL. A predetermined voltage is thereby applied to each of the upper electrodes E2. In other words, optimum voltages can be applied to the red sub-pixels SP1, the green sub-pixels SP2, and the blue sub-pixels SP3, respectively.

In the configuration example shown inFIG.28, the upper electrode E2is electrically connected to the power supply lines FL on both sides sandwiching the display portion DA, but may be connected to the power supply line FL on either of the sides.

FIG.29is a plan view showing another configuration example of the upper electrodes E2.

The configuration example shown inFIG.29is different from the configuration example shown inFIG.28in that each of the power supply lines FL extends at the display portion DA and that the upper electrode E2is in contact with the power supply line FL in contact holes CH21at the display portion DA.

In addition, the upper electrode E2extends to the outside of the display portion DA and is in contact with the power supply lines FL in the contact holes CH22. However, when the upper electrode E2is in contact with the power supply line FL at the display portion DA, the upper electrode E2may not be in contact with the power supply line FL outside the display portion DA.

FIG.30Ais a plan view showing yet another configuration example of the upper electrode E2.

The configuration example shown inFIG.30Ais different from the configuration example shown inFIG.28in that the upper electrode E2is arranged over the sub-pixels SP1, SP2, and SP3of different colors. The upper electrode E2extends in the second direction Y, is arranged at the display portion DA, and extends to the outside of the display portion DA.

The power supply lines FL are arranged outside the display portion DA, and overlap the upper electrode E2, in plan view. In a plurality of contact holes CH2, the upper electrode E2is in contact with the power supply lines FL. A predetermined voltage is thereby applied to the upper electrode E2.

In the configuration example shown inFIG.30A, the upper electrode E2is electrically connected to the power supply lines FL on both sides sandwiching the display portion DA, but may be connected to the power supply line FL on either of the sides.

FIG.30Bis a plan view showing yet another configuration example of the upper electrodes E2.

The configuration example shown inFIG.30Bis different from the configuration example shown inFIG.30Ain that each of the power supply lines FL extends at the display portion DA and that the upper electrode E2is in contact with the power supply line FL in contact holes CH21at the display portion DA.

In addition, the upper electrode E2extends to the outside of the display portion DA and is in contact with the power supply lines FL in the contact holes CH22. However, when the upper electrode E2is in contact with the power supply line FL at the display portion DA, the upper electrode E2may not be in contact with the power supply line FL outside the display portion DA.

FIG.31Ais a plan view showing yet another configuration example of the upper electrode E2.

In the example shown in the drawing, area of the sub-pixel SP3of blue (B) is larger than area of each of the sub-pixel SP1of red (R) and the sub-pixel SP2of green (G). In addition, as regards the length along the second direction Y, the sub-pixel SP3is longer than the sub-pixel SP1and the sub-pixel SP2.

At the display portion DA, the sub-pixels SP1and the sub-pixels SP3are alternately arranged along the first direction X. In addition, the sub-pixels SP2and the sub-pixels SP3are alternately arranged along the first direction X. The sub-pixels SP1and the sub-pixels SP2are alternately arranged along the second direction Y. The sub-pixels SP3are arranged in the second direction Y.

In a layout of the sub-pixels, the upper electrode E2is arranged over the sub-pixels SP1, SP2, and SP3of different colors, similarly to the configuration example shown inFIG.30A. In addition, the upper electrode E2extends in the second direction Y, is arranged at the display portion DA, and extends to the outside of the display portion DA.

The power supply lines FL are arranged outside the display portion DA, and overlap the upper electrode E2, in plan view. In a plurality of contact holes CH2, the upper electrode E2is in contact with the power supply lines FL. A predetermined voltage is thereby applied to the upper electrode E2.

FIG.31Bis a plan view showing yet another configuration example of the upper electrodes E2.

In the layout of the sub-pixels described with reference toFIG.31A, the upper electrodes E2formed in a strip shape are arranged at portions where a plurality of sub-pixels of the same color are arranged in the second direction Y, and the upper electrodes E2formed in an island shape are arranged at portions where the sub-pixels of different colors are arranged in the second direction Y.

In the example shown in the drawing, the sub-pixels SP3of blue (B) are arranged in the second direction Y. The upper electrode E2arranged on these sub-pixels SP3is formed in a strip shape extending in the second direction Y, is in contact with the power supply line FL in the contact hole CH21of the display portion DA, and is in contact with the power supply line FL in the contact holes CH22outside the display portion DA. However, the upper electrode E2may be in contact with the power supply line FL in either of the contact holes CH21and CH22.

The upper electrode E2arranged at each of the sub-pixel SP1of red (R) and the sub-pixel SP2of green (G) is formed in an island shape, and is in contact with the power supply line FL in the contact hole CH21of the display portion DA.

Embodiment

FIG.32is a plan view showing an embodiment.

The power supply lines FL are arranged at the display portion DA and extend to the outside of the display portion DA. At the display portion DA, the power supply lines FL do not overlap the contact holes CH1. The lower electrode E1of each of the display element20overlaps the contact hole CH1and also overlaps the power supply line FL. The contact hole CH21is formed to be arranged with the lower electrode E1and overlaps the power supply line FL. The contact hole CH22overlapping the supply line FL is formed outside the display portion DA. The upper electrode E2overlaps the lower electrode E1and the contact hole CH21at the display portion DA, and overlaps the contact hole CH22outside the display portion DA.

FIG.33is a cross-sectional view showing the display element20shown inFIG.32along line A-B.

A plurality of insulating layers I1to14are arranged between the substrate10and the insulating layer (first insulating layer)11. The insulating layer I1is arranged on the substrate10, the insulating layer12is arranged on the insulating layer I1, the insulating layer13is arranged on the insulating layer12, the insulating layer14is arranged on the insulating layer13, and the insulating layer11is arranged on the insulating layer14. The insulating layers I1to14are, for example, inorganic insulating layers formed of silicon nitride, silicon oxide, or the like.

A semiconductor SC1of the pixel switch2, and a semiconductor SC2of the drive transistor3are, for example, polycrystalline silicon and are located between the insulating layer I1and the insulating layer12. A drain electrode DE of the drive transistor3is located between the insulating layer14and the insulating layer11, and is in contact with the semiconductor SC2. The conductive material CD is in contact with the drain electrode DE, in the contact hole (first contact hole) CH1formed in the insulating layer11.

The power supply line FL is arranged on the insulating layer11. The insulating layer (second insulating layer)12is arranged on the insulating layer11, and includes the contact hoe (second contact hole) CH21which penetrates to the power supply line FL.

The lower electrode E1is arranged on the insulating layer12and is in contact with the conductive material CD in the contact hole CH1. The organic layer OR is stacked on the lower electrode E1. The coating layer50covers the end surface SS1of the lower electrode E1and the end surface SS2of the organic layer OR. In addition, the coating layer50is in contact with the insulating layer12outside the lower electrode E1.

The upper electrode E2covers the organic layer OR and the coating layer50. In addition, the upper electrode E2is in contact with the power supply line FL in the contact hole CH21outside the display element20.

According to such an embodiment, as described above, area contributing the display can be increased, undesired current leakage at the peripheral part of the organic layer OR and the like are suppressed, and the degradation in the performance of the display element20can be suppressed. In addition, a desired voltage can be applied to the upper electrode E2of each display element20by the power supply line FL arranged at the display portion DA. In other words, a uniform voltage can be applied to an entire area of the display portion DA.

All of the display devices that can be implemented by a person of ordinary skill in the art through arbitrary design changes to the display devices described above as embodiments of the present invention come within the scope of the present invention as long as they are in keeping with the spirit of the present invention.

Various types of the modified examples are easily conceivable within the category of the ideas of the present invention by a person of ordinary skill in the art and the modified examples are also considered to fall within the scope of the present invention. For example, additions, deletions or changes in design of the constituent elements or additions, omissions, or changes in condition of the processes arbitrarily conducted by a person of ordinary skill in the art, in the above embodiments, fall within the scope of the present invention as long as they are in keeping with the spirit of the present invention.

In addition, the other advantages of the aspects described in the embodiments, which are obvious from the descriptions of the present specification or which can be arbitrarily conceived by a person of ordinary skill in the art, are considered to be achievable by the present invention as a matter of course.