JP6525081B2 - Electro-optical device and electronic apparatus - Google Patents

Description

  The present invention relates to a self-emission type electro-optical device and an electronic apparatus provided with an optical resonant structure.

  Examples of the electro-optical device include an organic EL device provided with an organic electroluminescence (EL) element which is a light emitting element for each pixel. In such an organic EL device, it has been proposed to realize a color display by introducing an optical resonant structure into a pixel and extracting light of a resonant wavelength.

  For example, Patent Document 1 describes a pixel including a reflective layer, a light reflective and light transmissive counter electrode, and an insulating layer, a pixel electrode, and a light emitting layer between the reflective layer and the counter electrode. An electro-optical device is disclosed that includes a layer. In the electro-optical device of Patent Document 1, the insulating layer includes a first insulating layer, a second insulating layer, and a third insulating layer stacked in order from the reflective layer side, and an insulating layer between the reflective layer and the pixel electrode. An optical resonant structure has been proposed in which the layer configuration is changed for each pixel. That is, by changing the layer configuration of the insulating layer for each pixel, the optical path length in the optical resonant structure is adjusted, and light of a desired resonant wavelength is extracted.

JP, 2014-235959, A

  The electro-optical device described in Patent Document 1 shows an example in which white light emission can be obtained from the functional layer provided in each pixel. Also, an example is shown in which a color filter is disposed at each pixel. That is, of the white light emitted from the functional layer of the organic EL element, light of the resonant wavelength is intensified by the optical resonant structure, and is further extracted through the color filter.

  For example, in each pixel where different luminescent colors of blue (B), green (G) and red (R) are obtained, it is difficult to strictly control the emission intensity, and to extract light of the same emission intensity from each pixel In some cases, the magnitude of the current flowing to the organic EL element may be different for each of the B, G, and R pixels. Then, the current ratio between B, G and R pixels will be different. Therefore, when the electro-optical device is driven for a long time, the emission luminance of the organic EL element in the pixel where the current flows most may be lower than that of the other pixels. Therefore, when the B, G, and R pixels are caused to emit light for white display, for example, there is a problem that a chromaticity shift occurs due to a decrease in light emission luminance of any of the pixels.

  Also, in order to make the current ratio between the pixels uniform, for example, it is conceivable to change the characteristics of the transistor for each pixel or change the circuit configuration, but the problem is that the circuit configuration becomes complicated. was there.

  The present invention has been made to solve at least a part of the above-described problems, and can be realized as the following modes or application examples.

Application Example The electro-optical device according to this application example includes a reflection layer, a semi-transmission reflection layer, and an optical path length adjustment layer and a light emission function layer provided between the reflection layer and the semi-transmission reflection layer. The optical path length adjustment layer of the first pixel includes a luminance adjustment layer, and the optical path length adjustment layer of the second pixel does not include the luminance adjustment layer, and the first pixel and the second pixel are included , respectively. The consumption current in the first pixel when white light is emitted by the first pixel and the second pixel is 1⁄2 or more and 1 or less with respect to the consumption current in the second pixel .

According to this application example, when it is intended to obtain the same light emission luminance in the first pixel and the second pixel, the first pixel has the luminance adjustment layer, so a large amount of current can be obtained compared to the second pixel. It will be necessary to flush it. In other words, even if, for example, the magnitudes of the currents supplied to cause the light emitting functional layer to emit light with the same light emission luminance are different between the first pixel and the second pixel, the current flows to the first pixel based on the second pixel. The current can be increased and light emission of substantially the same luminance can be extracted from the first and second pixels. That is, the difference between the magnitudes of the currents flowing to the first and second pixels can be reduced, or the magnitudes of the currents can be made the same. That is, it is possible to provide an electro-optical device capable of making the current ratio between pixels uniform with a simple configuration without complicating the circuit configuration in the pixel circuit.
The electro-optical device according to the application example includes a red pixel, a green pixel, and a blue pixel, each of the red pixel and the green pixel is the first pixel, and the blue pixel is the second pixel. The consumption current in the red pixel when emitting white light by the red pixel, the green pixel and the blue pixel is 23.8% with respect to the total consumption current in the red pixel, the green pixel and the blue pixel. It is preferable that it is 38.8% or less.

In the electro-optical device according to the application example, the optical path length adjusting layer includes a light transmitting pixel electrode, and the brightness adjusting layer is provided between the reflective layer and the pixel electrode. preferable.
According to this configuration, the difference in magnitude of the current flowing between the first pixel and the second pixel can be obtained without affecting the light emission characteristic of the light emission function layer provided between the pixel electrode and the semitransparent reflection layer. It can be made smaller or the magnitude of the current can be made the same.

In the electro-optical device described in the application example, it is preferable that the brightness adjustment layer has a layer whose refractive index is smaller than the refractive index of the adjacent layer.
According to this configuration, the amount of light transmitted through the brightness adjustment layer can be adjusted by the difference in refractive index between adjacent layers.

In the electro-optical device described in the application example, the brightness adjustment layer may include a layer having a refractive index smaller than that of the adjacent layer, and a metal layer.
According to this configuration, it is possible to adjust the brightness using light reflection at the interface of the metal layer.

In the electro-optical device according to the application example, the metal layer is made of at least one metal selected from Ti, Mo, Ta, Al, Cu, and Cr, or an alloy containing the metal. .
According to this configuration, when a metal thin film is formed using these metals or alloys, it is possible to configure a metal layer having light transmittance and light reflectivity that exhibits a brightness adjustment function.

In the electro-optical device described in the application example, the adjacent layer is made of a silicon nitride film, and the layer having a small refractive index is made of a silicon oxide film.
According to this configuration, since the brightness adjustment layer includes the layer made of a silicon oxide film, it is possible to finely adjust the brightness by preventing a sharp decrease in brightness due to the provision of the brightness adjustment layer.

In the electro-optical device according to the application example, it is preferable that the first pixel and the second pixel have a reflection enhancing layer provided on the reflection layer.
According to this configuration, brighter emission luminance can be realized in the first pixel and the second pixel.

Application Example An electronic apparatus according to this application example includes the electro-optical device described in the application example.
According to this application example, since the electro-optical device capable of making the current ratio between the pixels uniform with a simple configuration without complicating the circuit configuration in the pixel circuit is provided, the light emission state is excellent in appearance. It is possible to provide an electronic device that is realized and cost-effective.

FIG. 1 is a schematic plan view showing the configuration of an organic EL device according to a first embodiment. The equivalent circuit schematic which shows the electric constitution of the luminescent pixel of the organic electroluminescent apparatus of 1st Embodiment. FIG. 2 is a schematic plan view showing the configuration of a light emitting pixel of the organic EL device of the first embodiment. FIG. 5 is a schematic cross-sectional view showing a structure when the light emitting pixel is cut along the X direction. FIG. 2 is a schematic cross-sectional view showing an optical resonant structure in a light emitting pixel. 6 is a flowchart showing a method of manufacturing the organic EL device according to the first embodiment. FIG. 7 is a schematic cross-sectional view showing the method of manufacturing the organic EL device according to the first embodiment. FIG. 7 is a schematic cross-sectional view showing the method of manufacturing the organic EL device according to the first embodiment. FIG. 7 is a schematic cross-sectional view showing the method of manufacturing the organic EL device according to the first embodiment. FIG. 7 is a schematic cross-sectional view showing the method of manufacturing the organic EL device according to the first embodiment. FIG. 7 is a schematic cross-sectional view showing the method of manufacturing the organic EL device according to the first embodiment. FIG. 7 is a schematic cross-sectional view showing the method of manufacturing the organic EL device according to the first embodiment. The schematic cross section which shows the optical resonant structure in the organic electroluminescent apparatus of 2nd Embodiment. The graph which shows the relationship of the optical distance and the brightness | luminance from the reflection layer to a metal layer in the luminescent pixel in which red light is obtained. The graph which shows the relationship of the optical distance and the brightness | luminance from the reflection layer to a metal layer in the light emission pixel in which green light is obtained. FIG. 5 is a schematic cross-sectional view showing an optical resonant structure of the organic EL device of Comparative Example 1; 6 is a table showing evaluation results of Comparative Example 1 and Example 1 and Example 2. The graph which shows the current ratio in the luminescent pixel of comparative example 1, example 1, and example 2. FIG. The schematic diagram which shows the head mounted display as an electronic device.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the drawings to be used are appropriately enlarged or reduced and displayed so that the parts to be described can be recognized.

First Embodiment
<Electro-optical device>
First, an organic EL device will be described as an example of the electro-optical device according to the present embodiment with reference to FIGS. 1 is a schematic plan view showing the configuration of the organic EL device, FIG. 2 is an equivalent circuit diagram showing the electrical configuration of the light emitting pixel of the organic EL device, and FIG. 3 is a schematic plan view showing the configuration of the light emitting pixel of the organic EL device It is.

  As shown in FIG. 1, an organic EL device 100 as an electro-optical device includes an element substrate 10, a plurality of light emitting pixels 20 arranged in a matrix in a display area E of the element substrate 10, and a plurality of light emitting pixels 20. A data line driving circuit 101 and a scanning line driving circuit 102, which are peripheral circuits for driving and controlling, and a plurality of external connection terminals 103 for electrically connecting to external circuits are provided. The organic EL device 100 of the present embodiment is an active drive type and top emission type light emitting device.

In the display area E, a light emitting pixel 20B capable of obtaining blue (B) light emission, a light emitting pixel 20G capable of obtaining green (G) light emission, and a light emitting pixel 20R capable of obtaining red (R) light emission ing. Further, light emitting pixels 20 capable of obtaining light of the same color are arranged in the vertical direction in the drawing, and light emitting pixels 20 capable of obtaining light emission of different colors are repeatedly arranged in the order of B, G, R in the horizontal direction in the drawing. ing. Such an arrangement of the light emitting pixels 20 is called a stripe method, but is not limited to this. For example, the arrangement in the lateral direction of the light emitting pixels 20 which can emit light of different colors may not be in the order of B, G, and R, and may be, for example, in the order of R, G, and B.
Hereinafter, the vertical direction in which the light emitting pixels 20 from which light emission of the same color is obtained is arranged is referred to as Y direction, and the direction orthogonal to the Y direction is described as X direction. Further, viewing the element substrate 10 from the light extraction direction of the light emitting pixel 20 will be described as a plan view.

  Although the detailed configuration of the light emitting pixel 20 will be described later, each of the light emitting pixels 20B, 20G, and 20R in the present embodiment is an organic electroluminescent element (hereinafter referred to as an organic EL element) as a light emitting element; A color filter corresponding to each of the colors of (1) to (4) is used to convert light emitted from the organic EL element into each color of B, G, and R to enable full color display. Moreover, the optical resonant structure which improves the brightness | luminance of a specific wavelength among the light emission wavelength range from an organic EL element is constructed | assembled for every light emission pixel 20B, 20G, and 20R.

  In the organic EL device 100, the light emitting pixels 20B, 20G, and 20R function as sub-pixels, and three light emitting pixels 20B, 20G, and 20R that can obtain light emission corresponding to B, G, and R enable image display. One pixel unit is configured. Note that the configuration of the pixel unit is not limited to this, and a light emitting pixel 20 capable of obtaining a luminescent color (including white) other than B, G, and R may be included in the pixel unit.

  A plurality of external connection terminals 103 are arranged in the X direction along the first side of the element substrate 10. Further, the data line drive circuit 101 is disposed between the external connection terminal 103 and the display area E in the Y direction, and extends in the X direction. In addition, a pair of scanning line driving circuits 102 is provided across the display area E in the X direction.

As described above, in the display area E, a plurality of light emitting pixels 20 are provided in a matrix, and as shown in FIG. 2, the element substrate 10 has scanning lines 11 as signal lines corresponding to the light emitting pixels 20. , The data line 12, the lighting control line 13, and the power supply line 14 are provided.
In the present embodiment, the scanning line 11 and the lighting control line 13 extend in parallel in the X direction, and the data line 12 and the power supply line 14 extend in parallel in the Y direction.
In the display area E, a plurality of scanning lines 11 and a plurality of lighting control lines 13 are provided corresponding to m rows in the plurality of light emitting pixels 20 arranged in a matrix, and the pair of scanning shown in FIG. It is connected to the line drive circuit 102. In addition, a plurality of data lines 12 and a plurality of power supply lines 14 are provided corresponding to the n columns in the plurality of light emitting pixels 20 arranged in a matrix, and the plurality of data lines 12 are the data shown in FIG. The plurality of power supply lines 14 are connected to the line drive circuit 101, and are connected to any of the plurality of external connection terminals 103.

Near the intersection between the scanning line 11 and the data line 12, the first transistor 21, the second transistor 22, the third transistor 23, the storage capacitor 24, and the organic EL element as a light emitting element, which constitute the pixel circuit of the light emitting pixel 20 30 are provided.
The organic EL element 30 has a pixel electrode 31 which is an anode, a counter electrode 36 which is a cathode, and a functional layer 35 including a light emitting layer, which is sandwiched between these electrodes. The counter electrode 36 is an electrode commonly provided across the plurality of light emitting pixels 20, and for example, lower potentials Vss and GND are applied to the power supply voltage Vdd applied to the power supply line 14.

  The first transistor 21 and the third transistor 23 are, for example, n-channel transistors. The second transistor 22 is, for example, a p-channel transistor.

The gate electrode of the first transistor 21 is connected to the scanning line 11, one current end is connected to the data line 12, and the other current end is connected to the gate electrode of the second transistor 22 and one electrode of the storage capacitance 24. It is connected.
One current end of the second transistor 22 is connected to the power supply line 14 and to the other electrode of the storage capacitor 24. The other current end of the second transistor 22 is connected to one current end of the third transistor 23. In other words, the second transistor 22 and the third transistor 23 share one current end of the pair of current ends.
The gate electrode of the third transistor 23 is connected to the lighting control line 13, and the other current end is connected to the pixel electrode 31 of the organic EL element 30.
One of the current terminals of each of the first transistor 21, the second transistor 22 and the third transistor 23 is a source, and the other is a drain.

  In such a pixel circuit, when the voltage level of the scanning signal Yi supplied from the scanning line driving circuit 102 to the scanning line 11 becomes Hi level, the n-channel first transistor 21 is turned on (ON). The data line 12 and the storage capacitor 24 are electrically connected via the first transistor 21 in the ON state (ON). When a data signal is supplied from the data line drive circuit 101 to the data line 12, a potential difference between the voltage level Vdata of the data signal and the power supply voltage Vdd applied to the power supply line 14 is stored in the storage capacitor 24.

  When the voltage level of the scanning signal Yi supplied from the scanning line drive circuit 102 to the scanning line 11 becomes low level, the n-channel first transistor 21 is turned off (OFF), and the gate-source distance of the second transistor 22 Voltage Vgs is held at a voltage when voltage level Vdata is applied. In addition, after the scanning signal Yi becomes low level, the voltage level of the lighting control signal Vgi supplied to the lighting control line 13 becomes Hi level, and the third transistor 23 is turned on (ON). Then, a current corresponding to the gate-source voltage Vgs of the second transistor 22 flows between the source and the drain of the second transistor 22. Specifically, the current flows from the power supply line 14 through the second transistor 22 and the third transistor 23 to the organic EL element 30.

  The organic EL element 30 emits light in accordance with the magnitude of the current flowing through the organic EL element 30. The current flowing through the organic EL element 30 is determined by the operating point of the second transistor 22 and the organic EL element 30 set by the voltage Vgs between the gate and the source of the second transistor 22. The voltage Vgs between the gate and source of the second transistor 22 is a voltage held in the storage capacitor 24 by the potential difference between the voltage level Vdata of the data line 12 and the power supply voltage Vdd when the scanning signal Yi is at the Hi level. Thus, the light emission luminance of the light emitting pixel 20 is defined by the voltage level Vdata of the data signal and the length of the period in which the third transistor 23 is in the on state. That is, according to the value of the voltage level Vdata in the data signal, it is possible to give gradation of luminance according to the image information in the light emitting pixel 20, and full color display is enabled.

In the present embodiment, the pixel circuit of the light emitting pixel 20 is not limited to having the three transistors 21, 22 and 23, and may have a switching transistor and a driving transistor. Further, the transistor forming the pixel circuit may be an n-channel transistor, a p-channel transistor, or may include both an n-channel transistor and a p-channel transistor. In addition, the transistor constituting the pixel circuit of the light emitting pixel 20 may be a MOS transistor having an active layer on a semiconductor substrate, may be a thin film transistor, or may be a field effect transistor.
The arrangement of the lighting control line 13 and the power supply line 14 which are signal lines other than the scanning line 11 and the data line 12 depends on the arrangement of the transistor and the storage capacitor 24 and is not limited thereto.
In the present embodiment, an example in which a MOS transistor having an active layer on a semiconductor substrate is adopted as a transistor forming the pixel circuit of the light emitting pixel 20 will be described below.

<Structure of light emitting pixel>
The specific configuration of the light emitting pixel 20 will be described with reference to FIG. As shown in FIG. 3, each of the light emitting pixels 20B, 20G, and 20R has a rectangular shape in plan view, and the longitudinal direction is disposed along the Y direction. Each of the light emitting pixels 20B, 20G and 20R is provided with the organic EL element 30 of the equivalent circuit shown in FIG. In order to distinguish the organic EL elements 30 provided for each of the light emitting pixels 20B, 20G, and 20R, the organic EL elements 30B, 30G, and 30R may be described. Further, in order to distinguish the pixel electrode 31 of the organic EL element 30 for each of the light emitting pixels 20B, 20G, and 20R, the pixel electrode 31 may be described as the pixel electrodes 31B, 31G, and 31R.

The light emitting pixel 20B is provided with a pixel electrode 31B and a contact portion 31Bc for electrically connecting the pixel electrode 31B and the third transistor 23. Similarly, the light emitting pixel 20G is provided with a pixel electrode 31G and a contact portion 31Gc for electrically connecting the pixel electrode 31G and the third transistor 23. The light emitting pixel 20R is provided with a pixel electrode 31R and a contact portion 31Rc for electrically connecting the pixel electrode 31R and the third transistor 23.
The pixel electrodes 31B, 31G, and 31R are also substantially rectangular in plan view, and the contact portions 31Bc, 31Gc, and 31Rc are disposed on the upper side in the longitudinal direction.

  Each of the light emitting pixels 20B, 20G, and 20R electrically insulates adjacent pixel electrodes 31 from each other, and an opening 29B for defining a region in contact with the functional layer 35 (see FIG. 4) on the pixel electrodes 31B, 31G, and 31R. , 29G, and 29R are formed.

  Further, the substantial functions as the pixel electrodes 31B, 31G, 31R for injecting charges into the functional layers 35 of the organic EL elements 30B, 30G, 30R are defined by the openings 29B, 29G, 29R in the above-mentioned insulating structure. , And respectively in contact with the functional layer 35. The openings 29B, 29G, and 29R are defined by a fifth insulating layer 29 (see FIG. 4) described later, and in each of the pixel electrodes 31B, 31G, and 31R, the contact portions 31Bc, 31Gc, and 31Rc are fifth insulation layers. Covered by layer 29 and mutually insulated. In the present embodiment, the shapes and sizes of the openings 29B, 29G, and 29R are the same.

  Next, the structure of the light emitting pixel 20 will be described with reference to FIG. FIG. 4 is a schematic cross-sectional view showing the structure when the light emitting pixel is cut along the X direction. Note that in FIG. 4, among the pixel circuits, the first transistor 21 and the second transistor 22 and wirings related to the first transistor 21 and the second transistor 22 are shown, and the third transistor 23 is omitted.

  As shown in FIG. 4, the organic EL device 100 includes the element substrate 10 on which the light emitting pixels 20 B, 20 G, and 20 R, the color filter 50 and the like are formed, and the translucent sealing substrate 70. The element substrate 10 and the sealing substrate 70 are bonded by a resin layer 60 having both adhesiveness and transparency. The color filter 50 has filter layers 50B, 50G, and 50R corresponding to the respective colors B, G, and R. The filter layers 50B, 50G, and 50R are disposed on the element substrate 10 so as to correspond to the light emitting pixels 20B, 20G, and 20R, respectively. The light emitted from the functional layer 35 passes through any one of the corresponding filter layers 50B, 50G, and 50R and is emitted from the sealing substrate 70 side. That is, the organic EL device 100 has a top emission structure in which light is extracted from the sealing substrate 70 side.

As the base 10s of the element substrate 10, not only a transparent glass substrate but also an opaque ceramic substrate or a semiconductor substrate can be used because the organic EL device 100 has a top emission structure.
In the present embodiment, a semiconductor substrate is used as the substrate 10s. The semiconductor substrate is, for example, a silicon substrate.

  In the base material 10s, an ion implantation which is an active layer formed by implanting a well 10w formed by implanting ions into a semiconductor substrate and a different type of ion from the well 10w to the well 10w A unit 10d is provided. The well portion 10 w functions as a channel of the transistors 21, 22, 23 in the light emitting pixel 20, and the ion implantation portion 10 d functions as a part of the source / drain or wiring of the transistors 21, 22, 23 in the light emitting pixel 20. It is.

  Next, an insulating film 10a is formed to cover the surface of the base 10s on which the ion implantation portion 10d and the well portion 10w are formed. The insulating film 10a functions as a gate insulating film. A conductive film such as polysilicon is formed on the insulating film 10a and patterned to form the gate electrode 22g. The gate electrode 22 g is disposed to face the well 10 w functioning as a channel of the second transistor 22. The gate electrodes are similarly arranged in the other first and second transistors 21 and 23 as well.

  Next, a first interlayer insulating film 15 covering the gate electrode 22g is formed. Then, through the first interlayer insulating film 15, for example, contact holes reaching the drain of the first transistor 21 and the gate electrode 22g of the second transistor 22 are formed. A conductive film is formed to cover at least the inside of the contact hole and to cover the surface of the first interlayer insulating film 15. By patterning the conductive film, for example, the drain electrode 21d of the first transistor 21 and the gate of the second transistor 22 are formed. A wire connected to the electrode 22g is formed.

  Next, a second interlayer insulating film 16 which covers various wirings on the first interlayer insulating film 15 is formed. Then, a contact hole penetrating the second interlayer insulating film 16 and reaching the wiring formed on the first interlayer insulating film 15 is formed. A conductive film is formed so as to cover at least the inside of the contact hole and to cover the surface of the second interlayer insulating film 16 and by patterning the conductive film, for example, one electrode 24 a of the storage capacitor 24 and the gate of the second transistor 22. A contact portion for electrically connecting the electrode 22g is formed. In addition, the data line 12 is formed in the same layer as the one electrode 24a. The data line 12 is connected to the source of the first transistor 21 by a wire not shown in FIG.

  Next, a dielectric layer (not shown in FIG. 4) covering at least one of the electrodes 24a is formed. Further, the other electrode 24b of the storage capacitor 24 is formed at a position facing the one electrode 24a with the dielectric layer interposed therebetween. Thereby, a storage capacitor 24 having a dielectric layer is formed between the pair of electrodes 24a and 24b.

Next, a third interlayer insulating film 17 covering the data line 12 and the storage capacitor 24 is formed. Through the third interlayer insulating film 17, for example, a contact hole reaching the other electrode 24b of the storage capacitor 24 and a wiring formed on the second interlayer insulating film 16 is formed. A conductive film is formed to cover at least the inside of the contact hole and to cover the surface of the third interlayer insulating film 17. By patterning the conductive film, a contact for connecting the power supply line 14 or the power supply line 14 to the other electrode 24b A part is formed. In the present embodiment, the power supply line 14 is formed using, for example, a metal such as Al (aluminum) or Ag (silver) or an alloy of these metals, which has both light reflectivity and conductivity. Further, the power supply line 14 faces the pixel electrodes 31B, 31G, and 31R except for the portions overlapping the contact portions 31Bc, 31Gc, and 31Rc (see FIG. 3) of the light emitting pixels 20B, 20G, and 20R. It is formed to constitute a plane. The portion of the power supply line 14 facing the pixel electrodes 31B, 31G, and 31R functions as a reflective layer.
Note that the power supply line 14 may be formed of a conductive material, and a reflective layer may be provided between the power supply line 14 and the pixel electrodes 31B, 31G, and 31R.

  Although not illustrated in FIG. 4, the base 10 s is provided with a well portion 10 w in which the second transistor 22 and the third transistor 23 are shared. The well 10w is provided with three ion implantation units 10d. Among the three ion implantation units 10 d, the ion implantation unit 10 d located on the center side functions as a drain shared by the second transistor 22 and the third transistor 23. An insulating film 10a covering the well 10w is provided. Then, a conductive film such as polysilicon is formed to cover the insulating film 10a, and by patterning the conductive film, the gate electrode of the second transistor 22 and the gate electrode of the third transistor 23 are formed on the insulating film 10a. Is formed. Each gate electrode is disposed to face a portion functioning as a channel in the well 10w between the central ion implantation 10d and the end ion implant 10d described above.

  Next, the gate electrode of the second transistor 22 is a contact hole passing through the first interlayer insulating film 15 and the second interlayer insulating film 16 to form one of the storage capacitors 24 provided on the second interlayer insulating film 16. It is connected to the electrode 24a. The source electrode of the second transistor 22 is connected to the power supply line 14 provided on the third interlayer insulating film 17 by a contact hole penetrating the second interlayer insulating film 16 and the third interlayer insulating film 17.

  The gate electrode of the third transistor 23 is connected to the lighting control line 13 provided on the first interlayer insulating film 15 by a contact hole penetrating the first interlayer insulating film 15. In addition to the lighting control line 13, the scanning line 11 is provided on the first interlayer insulating film 15. The scanning line 11 is also connected to the gate of the first transistor 21 via a contact hole penetrating the first interlayer insulating film 15.

  The source electrode of the third transistor 23 is connected to a wire provided on the insulating layer 28 by a contact hole penetrating the insulating layer 28 on the power supply line 14 and the second interlayer insulating film 16 and the third interlayer insulating film 17. It is done. The wiring is provided, for example, corresponding to the contact portion 31Gc of the light emitting pixel 20G, and the wiring is in contact with the pixel electrode 31G in the contact portion 31Gc, whereby electrical connection is achieved. .

  The electrical connection between the pixel electrode 31B of the light emitting pixel 20B and the pixel electrode 31R of the light emitting pixel 20R and the source electrode of the third transistor 23 corresponding to each of the pixel electrodes 31B and 31R is performed through the contact portion 31Bc and the contact portion 31Rc, similarly to (See Figure 3).

  The organic EL element 30 is provided on the power supply line 14 which functions as a reflective layer. In addition, an optical resonant structure capable of extracting light of different resonant wavelengths for each of the light emitting pixels 20B, 20G, and 20R is constructed on the power supply line 14. The power supply line 14 is formed to cover the surface of the third interlayer insulating film 17 over the display area E in which the light emitting pixels 20B, 20G, and 20R are provided in a plan view. Further, the power supply line 14 is patterned except for the portion provided with the contact portions 31Bc, 31Gc, and 31Rc for electrically connecting the pixel electrodes 31B, 31G, and 31R to the corresponding third transistors 23. . Therefore, the unevenness due to the configuration of the pixel circuit provided in the lower layer than the power supply line 14 hardly affects the optical resonant structure provided in the upper layer than the power supply line 14.

  A sealing layer 40 is formed at least over the display area E so as to cover the organic EL elements 30 provided for each of the light emitting pixels 20B, 20G, and 20R. The sealing layer 40 is configured to include a first sealing film 41, a buffer layer 42, and a second sealing film 43 stacked in order from the counter electrode 36 side.

  The first sealing film 41 is hard to transmit gas such as moisture and oxygen (gas barrier property) and can obtain transparency. For example, metal oxide such as silicon oxide, silicon nitride, silicon oxynitride, titanium oxide, etc. The inorganic compound of As a forming method, it is preferable to use a vapor phase process capable of forming a dense film at low temperature, for example, high density plasma film forming method such as plasma CVD method or ECR plasma sputtering method, vacuum evaporation method, ion plating I can mention the law. The film thickness of the first sealing film 41 is approximately 200 nm to 400 nm.

  The surface of the first sealing film 41 is uneven due to the influence of a structure such as the organic EL element 30 provided in the lower layer. In the present embodiment, at least the display area E of the surface of the first sealing film 41 is covered in order to prevent the deterioration of the sealing function of the second sealing film 43 caused by the adhesion of the unevenness and the foreign substance, etc. A buffer layer 42 is formed in order to ease and planarize the unevenness in at least the display area E.

  The buffer layer 42 is, for example, an organic resin layer formed by applying and drying a solution obtained by dissolving a transparent organic resin in a solvent by a printing method or a spin coating method. An epoxy resin etc. can be mentioned as an organic resin. Since the buffer layer 42 relieves the unevenness on the surface of the first sealing film 41 and covers and flattens the foreign matter attached to the first sealing film 41, its film thickness is preferably 1 μm to 5 μm, In the present embodiment, the buffer layer 42 having a film thickness of about 3 μm is formed using an epoxy resin. The buffer layer 42 is preferably formed to cover at least the functional layer 35 in a plan view, and to cover the counter electrode 36. By forming the buffer layer 42 so as to cover at least the functional layer 35, the unevenness at the end of the functional layer 35 can be alleviated. The buffer layer 42 may be formed to cover at least a part of the display area E side of the peripheral circuits (the data line driving circuit 101 and the pair of scanning line driving circuits 102) in addition to the display area E ( See Figure 1).

  Similar to the first sealing film 41, the second sealing film 43 covering the buffer layer 42 is formed using an inorganic compound that has both transparency and gas barrier properties and is excellent in water resistance and heat resistance. Examples of the inorganic compound include silicon oxide, silicon nitride and silicon oxynitride. The second sealing film 43 can be formed using the same method as the first sealing film 41. The film thickness of the second sealing film 43 is preferably in the range of 200 nm to 700 nm, and more preferably in the range of 300 nm to 400 nm, so as to prevent generation of cracks during film formation. If the buffer layer 42 is formed so as to cover the counter electrode 36, the end portion of the counter electrode 36 can be covered by the first sealing film 41 and the second sealing film 43 stacked directly thereon.

  The color filter 50 is formed on the sealing layer 40 having a flat surface. The filter layers 50B, 50G, and 50R of the color filter 50 are formed by applying a photosensitive resin containing a pigment corresponding to each color on the sealing layer 40, and exposing and developing.

<Optical resonance structure>
Next, the optical resonant structure and the configuration of the organic EL element 30 in the organic EL device 100 of the present embodiment will be described with reference to FIG. FIG. 5 is a schematic cross-sectional view showing an optical resonant structure in a light emitting pixel.

  The organic EL element 30 in the present embodiment has a pixel electrode 31 which is a translucent anode, a counter electrode 36 which is a semitransparent reflective cathode, and a functional layer 35 sandwiched between these electrodes. ing. The functional layer 35 includes a hole injection layer (HIL) 32, an organic light emitting layer (EML) 33, and an electron transport layer (ETL) 34 stacked in order from the pixel electrode 31 side.

  By applying a drive potential between the pixel electrode 31 and the counter electrode 36, holes are injected from the pixel electrode 31 to the functional layer 35, and electrons are injected from the counter electrode 36 to the functional layer 35. In the organic light emitting layer 33 included in the functional layer 35, when the injected holes and electrons form an exciton (exciton) and the exciton (exciton) disappears (when the electron and the hole recombine) Part of the energy is emitted as fluorescence or phosphorescence.

  The functional layer 35 improves or controls the injectability and transportability of holes and electrons to the organic light emitting layer 33 in addition to the hole injection layer 32, the organic light emitting layer 33, and the electron transporting layer 34, for example, a hole transporting layer And an electron injection layer or an intermediate layer may be included.

  In the present embodiment, white light is obtained from the organic light emitting layer 33 of the functional layer 35. Therefore, the functional layer 35 is commonly formed across the light emitting pixels 20B, 20G, and 20R. White light can be realized by combining organic light emitting layers capable of obtaining blue (B), green (G) and red (R) light emission. In addition, pseudo white light can be obtained even by combining organic light emitting layers in which blue (B) and yellow (Y) light emission can be obtained.

  In the present embodiment, the white light emitted from the organic EL element 30 is transmitted through the color filter 50 to obtain a desired light emission color for each of the light emitting pixels 20B, 20G, and 20R. In addition, an optical resonant structure is constructed between the power supply line 14 functioning as a reflective layer and the counter electrode 36 for each of the light emitting pixels 20B, 20G, and 20R, and the resonance corresponding to each of the B, G, and R emission colors Luminescent-enhanced light emission is obtained at the wavelength.

  The resonant wavelength of each of the light emitting pixels 20B, 20G, and 20R is determined by the optical distance D (also referred to as an optical path length) between the power supply line 14 as the reflective layer and the counter electrode 36. It is set to satisfy (1).

D = {(2πm + φL + φU) / 4π} λ (1)
m is a positive integer (m = 0, 1, 2...), φL is a phase shift in reflection at the reflection layer, φU is a phase shift in reflection at the counter electrode 36, λ is a peak wavelength of the standing wave .

  The optical distance D in the light resonance structure of the light emitting pixels 20B, 20G, and 20R increases in the order of B, G, and R, and a plurality of insulations disposed between the power supply line 14 (reflection layer) and the pixel electrode 31 It is adjusted by making the composition of layers different. Specifically, the first insulating layer 25 and the second insulating layer 26 exist between the power supply line 14 and the pixel electrode 31B, and the first insulating layer 25 and the second insulating layer 26 exist between the power supply line 14 and the pixel electrode 31G. In addition to the second insulating layer 26, a fourth insulating layer 27b exists, and the first insulating layer 25, the second insulating layer 26, the third insulating layer 27a, and the fourth insulating layer are provided between the power supply line 14 and the pixel electrode 31R. Due to the presence of the layer 27b, the optical distance D is different for each of the light emitting pixels 20B, 20G, and 20R. The optical distance of each layer in the optical resonant structure can be represented by the product of the film thickness (t) of each layer through which light passes and the refractive index (n).

  For example, the peak wavelength (resonance wavelength) of the luminance in the light emitting pixel 20B is set to 470 nm. Similarly, the peak wavelength (resonance wavelength) of luminance in the light emitting pixel 20G is set to 540 nm, and the peak wavelength (resonance wavelength) of luminance in the light emitting pixel 20R is set to 610 nm.

In order to realize the above peak wavelength, for example, the film thickness of the pixel electrodes 31B, 31G, and 31R made of a transparent conductive film such as ITO is approximately 20 nm, the refractive index is 1.8, and the film thickness of the functional layer 35 is approximately 110 nm. The refractive index is 1.8. When the film thickness of each insulating layer between the power supply line 14 (reflecting layer) and the counter electrode 36 is calculated with m = 1 in the formula (1), the refractive index of the light emitting pixel 20B is 1.46. The film thickness of the first insulating layer 25 made of SiO ₂ is 35 nm, the film thickness of the second insulating layer 26 made of SiN having a refractive index of 1.8 is 45 nm, and the total film thickness is 80 nm. In the light emitting pixel 20G, the film thickness of the fourth insulating layer 27b made of SiO ₂ having a refractive index of 1.46 is 44 nm, and the total film thickness of the first insulating layer 25 and the second insulating layer 26 is 124 nm. Become. In the light emitting pixel 20R, the film thickness of the third insulating layer 27a and the fourth insulating layer 27b made of SiO ₂ is 100 nm, and the total film thickness of the first insulating layer 25 and the second insulating layer 26 is 180 nm.

In the present embodiment, the first insulating layer 25 which is commonly provided over the light emitting pixels 20B, 20G, and 20R and covers the power supply line 14 functioning as a reflective layer is formed using SiO ₂ as described above. It functions as a reflection enhancing layer to improve light reflectivity in the present invention. Therefore, it includes the second insulating layer 26, the third insulating layer 27a, and the fourth insulating layer 27b provided to make the optical distance D of the light resonant structure in each of the light emitting pixels 20B, 20G, and 20R substantially different. The insulating layer 28 functions as an optical path length adjusting layer in the present invention. Hereinafter, the reference numeral of the insulating layer 28 is used to refer to an optical path length adjusting layer 28.

  Further, in each of the light resonance structures of the light emitting pixels 20B, 20G, and 20R, the optical distance D of the light resonance structure is the first insulating layer 25, the second insulating layer 26, and the like in order to accurately realize the peak wavelength. The thickness and refractive index of each of the third insulating layer 27a and the fourth insulating layer 27b, the thickness and refractive index of the pixel electrode 31 and the functional layer 35, and the extinction coefficient of the power supply line 14 and the counter electrode 36 as a reflective layer are described. Set in consideration. Also, the refractive index of the layer through which light is transmitted depends strictly on the wavelength of the light to be transmitted.

Furthermore, in the optical resonance structure of the present embodiment, the optical path length adjustment layer 28 is a layer having a smaller refractive index than the refractive index of the adjacent layer (the second insulating layer 26) (third insulating layer 27a and fourth insulating layer 27b , And the reflection of light not only at the interface between the reflective layer 14 and the first insulating layer 25 but also at the interfaces between the second insulating layer 26 and the third insulating layer 27a and the fourth insulating layer 27b. Is the structure that causes Thereby, in the light emitting pixel 20G, when no reflection occurs at the interface between the second insulating layer 26 and the fourth insulating layer 27b, that is, the second insulating layer 26 and the fourth insulating layer 27b are formed of the same material. Compared to the case, the intensity (brightness) of light extracted from the light emitting pixel 20G is reduced. Similarly, in the light emitting pixel 20R, when no reflection occurs at the interface between the second insulating layer 26 and the third insulating layer 27a, that is, the second insulating layer 26 and the third insulating layer 27a are made of the same material. Compared to the case, the intensity (brightness) of light extracted from the light emitting pixel 20R is reduced. That is, in the light emitting pixel 20G, the fourth insulating layer 27b of the optical path length adjusting layer 28 functions as the brightness adjusting layer of the present invention, and in the light emitting pixel 20R, the third insulating layer 27a of the optical path length adjusting layer 28 It functions as a brightness control layer of the invention. In the light emitting pixel 20R, the third insulating layer 27a and the fourth insulating layer 27b function as a brightness adjustment layer because the third insulating layer 27a and the fourth insulating layer 27b are formed using SiO _2. It is also good.

<Method of manufacturing electro-optical device>
Next, a method of manufacturing the organic EL device 100 as an electro-optical device will be described with reference to FIGS. 6 is a flowchart showing a method of manufacturing an organic EL device, and FIGS. 7 to 12 are schematic cross-sectional views showing a method of manufacturing an organic EL device. The characterizing portion of the present invention is mainly in the process of forming the optical path length adjusting layer 28 in the element substrate 10. Therefore, hereinafter, features of the method of manufacturing the element substrate 10 in the method of manufacturing the organic EL device 100 will be described.

  As shown in FIG. 6, in the method of manufacturing the element substrate 10 of the present embodiment, a reflection increasing layer forming step (step S1), an optical path length adjusting layer forming step (step S2), a pixel electrode forming step (step S3) It comprises at least a layer forming step (step S4) and a counter electrode forming step (step S5). As the method of forming the pixel circuit and the wiring connected to the pixel circuit described above on the base material 10s of the element substrate 10 and the method of forming the power supply line 14 as the reflective layer, the known method may be used as described above. it can. In the following description, the reflective layer will be described as the reflective layer 14 using the symbol of the power supply line 14.

In the step of forming the reflection-increasing layer in step S1 and the step of forming the optical path length adjustment layer in step S2, first, as shown in FIG. 7, the first insulating layer 25, the second insulating layer 26, the third insulating layer on the reflective layer 14 The layers 27a are formed by depositing in this order. The first insulating layer 25 and the third insulating layer 27a are formed of, for example, SiO ₂ by CVD. The second insulating layer 26 is formed, for example, of SiN by the CVD method or the like. As described above, the film thickness of the aim in each insulating layer is, for example, 35 nm for the first insulating layer 25 functioning as a reflection enhancing layer, the third insulating layer 27 a functioning as a brightness adjustment layer, and the second insulating layer 26 for example 45 nm. Is 56 nm, for example.

  Then, as shown in FIG. 8, a photosensitive resist layer is formed to cover the third insulating layer 27a, and this is exposed and developed to form a resist pattern 81 having an opening 81a. The opening 81a is formed across the adjacent light emitting pixels 20B and the light emitting pixels 20G. As shown in FIG. 9, an opening 27c is formed in the third insulating layer 27a by dry etching the third insulating layer 27a using, for example, a fluorine-based processing gas via such a resist pattern 81. . The resist pattern 81 is removed after the dry etching. As shown in FIG. 3, the opening 27c is formed across the adjacent light emitting pixels 20B and the light emitting pixels 20G in the region excluding the contact parts 31Bc and 31Gc of the light emitting pixels 20B and 20G.

Subsequently, as shown in FIG. 10, a fourth insulating layer 27b is formed so as to cover the third insulating layer 27a and the opening 27c. The fourth insulating layer 27b is also formed of, for example, SiO ₂ by CVD. Then, a photosensitive resist layer is formed so as to cover the fourth insulating layer 27b, and this is exposed and developed to form a resist pattern 82 having an opening 82a. The opening 82a is formed corresponding to the light emitting pixel 20B. As shown in FIG. 11, the fourth insulating layer 27b is exposed to the fourth insulating layer 27b by dry etching the fourth insulating layer 27b exposed in the opening 82a using such a resist pattern 82 using, for example, a fluorine-based processing gas. An opening 27d is formed. Since the second insulating layer 26 made of SiN has a slower etching rate in dry etching than SiO ₂ , the second insulating layer 26 can function as an etching stop film in dry etching. After dry etching, the resist pattern 82 is removed. As shown in FIG. 3, the opening 27d is formed corresponding to the inside of the light emitting pixel 20B in the opening 27c formed between the light emitting pixel 20B and the light emitting pixel 20G adjacent to each other. Thus, optical path length adjustment layers 28 having different optical distances in the light emitting pixels 20B, 20G, and 20R are completed. Then, the process proceeds to step S3.

  In the pixel electrode forming step of step S3, a transparent conductive film such as ITO is formed to cover the optical path length adjusting layer 28, and the film is patterned to form the inside of the opening 27d as shown in FIG. The pixel electrode 31B is formed on the second insulating layer 26, the pixel electrode 31G is formed on the fourth insulating layer 27b in the opening 27c, and the pixel electrode 31R is formed on the fourth insulating layer 27b. In addition, the film thickness of the aim of a transparent conductive film is about 20 nm, for example. Then, the process proceeds to step S4.

  In the functional layer forming step of step S4, the functional layer 35 is formed on the pixel electrodes 31B, 31G, and 31R in each of the light emitting pixels 20B, 20G, and 20R. As described above, in the present embodiment, the functional layer 35 is configured by the hole injection layer 32, the organic light emitting layer 33, and the electron transport layer 34. Also, these layers are commonly formed across the light emitting pixels 20B, 20G, and 20R. The configuration and formation method of each layer of the functional layer 35 are not particularly limited, and for example, known methods such as dry film forming method such as evaporation method and wet film forming method such as spin coating can be used. Further, the dry film forming method and the wet film forming method may be used in combination depending on the functional layer forming material to be used. In the present embodiment, the hole injection layer 32, the organic light emitting layer 33, and the electron transport layer 34 are formed using a vapor deposition method. The film thickness of the hole injection layer 32 in the functional layer 35 is, for example, 30 nm, the film thickness of the organic light emitting layer 33 is, for example, 55 nm, and the film thickness of the electron transport layer 34 is, for example, 25 nm. That is, the film thickness of the purpose of the functional layer 35 is 110 nm which is the total value of the film thickness of the aim of these layers. Then, the process proceeds to step S5.

  In the counter electrode forming step of step S5, the counter electrode 36 is formed across the light emitting pixels 20B, 20G, and 20R so as to cover the functional layer 35 formed in step S4. In the present embodiment, Mg and Ag are co-evaporated to form the counter electrode 36 made of a thin film of MgAg alloy having a film thickness of about 20 nm.

  Thereafter, the element substrate 10 is completed through the steps of forming the sealing layer 40 covering the counter electrode 36 and forming the color filter 50 on the sealing layer 40 as described above. Furthermore, the organic EL device 100 is completed through the process of bonding the element substrate 10 and the sealing substrate 70 via the resin layer 60 (see FIG. 4 or FIG. 5).

According to the first embodiment, the following effects can be obtained.
(1) The optical path length adjustment layer 28 in the light resonance structure of the light emitting pixel 20G includes the fourth insulating layer 27 b functioning as a luminance adjustment layer. Similarly, the optical path length adjusting layer 28 in the light resonant structure of the light emitting pixel 20R has a third insulating layer 27a (or a third insulating layer 27a and a fourth insulating layer 27b) functioning as a brightness adjusting layer. For example, when displaying white, it is necessary to increase the magnitude of the current supplied to the organic EL element 30B of the light emitting pixel 20B more than the magnitude of the current supplied to the organic EL elements 30G and 30R of the light emitting pixels 20G and 20R. The current consumption is different among the light emitting pixels 20B, 20G, and 20R, and the current ratio is not uniform. When the optical path length adjusting layer 28 of the light emitting pixels 20G and 20R includes a brightness adjusting layer, when white is displayed, the magnitude of the current flowing to the organic EL elements 30G and 30R of the light emitting pixels 20G and 20R is increased. Therefore, it is possible to reduce the difference in the magnitude of the current supplied to the organic EL elements 30B, 30G, and 30R of the light emitting pixels 20B, 20G, and 20R, or to make the current ratio uniform.

  (2) The third insulating layer 27 a (fourth insulating layer 27 b) functioning as a luminance adjustment layer is provided between the reflective layer 14 and the pixel electrode 31. Therefore, the difference between the magnitudes of the currents supplied to the organic EL elements 30B, 30G, and 30R of the light emitting pixels 20B, 20G, and 20R is reduced without affecting the light emission characteristics of the functional layer 35 provided on the pixel electrode 31. Alternatively, the current ratio can be made uniform.

(3) The third insulating layer 27a (the fourth insulating layer 27b) functioning as the brightness adjusting layer is formed in contact with the second insulating layer 26 made of SiO ₂ and made of SiN having a refractive index larger than that of SiO ₂ . Thereby, light is reflected at the interface between the second insulating layer 26 and the third insulating layer 27a (the fourth insulating layer 27b), and the light emission luminance in the light emitting pixels 20G and 20R is adjusted. That is, since the third insulating layer 27a (fourth insulating layer 27b) functioning as the brightness adjustment layer is formed using the light transmissive SiO ₂ film, the emission brightness can be adjusted with high accuracy.

Second Embodiment
<Other electro-optical devices>
Next, as another electro-optical device having the optical resonant structure of the second embodiment, an organic EL device will be described as an example with reference to FIG. FIG. 13 is a schematic cross-sectional view showing an optical resonant structure in the organic EL device of the second embodiment. The organic EL device of the second embodiment is different from the organic EL device 100 of the first embodiment in the form of the brightness adjustment layer in the light resonance structure. Therefore, the same components as those of the organic EL device 100 are denoted by the same reference numerals and detailed description thereof is omitted.

  As shown in FIG. 13, the organic EL device 200 as the electro-optical device of this embodiment includes an element substrate 210 including light emitting pixels 20 B, 20 G, and 20 R capable of obtaining different light emission colors, and an element via a resin layer 60. And a translucent sealing substrate 70 disposed opposite to the substrate 210. The element substrate 210 corresponds to the reflective layer 14 and the first insulating layer 25 commonly formed over the light emitting pixels 20B, 20G, and 20R, and the light emitting pixels 20B, 20G, and 20R on the base 10s. The light path length adjustment layer 28 provided, the organic EL elements 30B, 30G, and 30R, and the color filter 50 (filter layers 50B, 50G, and 50R) are provided. The filter layers 50B, 50G, and 50R are disposed on the sealing layer 40 covering the organic EL elements 30B, 30G, and 30R.

  Each of the organic EL elements 30B, 30G, and 30R has a functional layer 35 sandwiched between the pixel electrode 31 which is an anode and the counter electrode 36 which is a cathode. The functional layer 35 includes a hole injection layer 32, an organic light emitting layer 33, and an electron transport layer 34 stacked in order from the pixel electrode 31 side, and the functional layer 35 emits white light. White light is converted into desired color light by transmitting through the filter layers 50B, 50G, and 50R, and is extracted from the sealing substrate 70 side.

  The light resonant structure in the organic EL device 200 includes the first insulating layer 25 and the second insulating layer 26 between the reflective layer 14 and the pixel electrode 31B in the light emitting pixel 20B. In addition to the first insulating layer 25 and the second insulating layer 26, a metal layer 27m and a fourth insulating layer 27b are provided between the reflective layer 14 and the pixel electrode 31G in the light emitting pixel 20G. In addition to the first insulating layer 25 and the second insulating layer 26, the light emitting pixel 20R includes a metal layer 27m, a third insulating layer 27a, and a fourth insulating layer 27b.

  That is, in addition to the second insulating layer 26, the third insulating layer 27a, and the fourth insulating layer 27b (a layer having a smaller refractive index than the second insulating layer 26), the optical path length adjusting layer 28 of the present embodiment is a metal layer 27m. The The metal layer 27m is made of, for example, at least one metal selected from Ti, Mo, Ta, Al, Cu, and Cr or an alloy containing the metal, and has light transparency and light reflectivity. For example, it is formed as a metal thin film using a sputtering method or the like.

In the optical resonant structure, by making the layer configuration between the reflective layer 14 and the pixel electrode 31 different in the light emitting pixels 20B, 20G, and 20R, light having a resonant wavelength (peak wavelength) of, for example, 470 nm is extracted from the light emitting pixel 20B. The light having a resonant wavelength (peak wavelength) of, for example, 570 nm is extracted from the light emitting pixel 20G, and the light having a resonant wavelength (peak wavelength) of, for example, 610 nm is extracted from the light emitting pixel 20R. In addition, the luminance is adjusted in the light emitting pixels 20G and 20R provided with the metal layer 27m. In the case of extracting light of the above-mentioned resonant wavelength (peak wavelength), for example, the target film thickness of the first insulating layer 25 in the case of forming using SiO ₂ is 35 nm, and the second insulating layer 26 in the case of forming using SiN. The film thickness of the target of the metal layer 27m is 45 nm, the film thickness of the metal layer 27m is 2 nm when the film is formed using TiN, and the film thickness of the third insulating layer 27a is 56 nm when the film is formed using SiO ₂ . The film thickness of the aim of the fourth insulating layer 27b is 44 nm, and the film thickness of the aim of the pixel electrodes 31B, 31G, and 31R when formed using ITO is 20 nm.

  Next, the relationship between the position of the metal layer 27m between the reflective layer 14 and the pixel electrodes 31G and 31R and the light emission luminance (hereinafter simply referred to as "luminance") will be described with reference to FIGS. 14 and 15. Do. FIG. 14 is a graph showing the relationship between the optical distance from the reflective layer to the metal layer and the luminance in the light emitting pixel capable of obtaining red light, and FIG. 15 is the optical system from the reflective layer to the metal layer in the light emitting pixel capable of obtaining green light It is a graph which shows the relationship between distance and brightness. FIG. 14 and FIG. 15 are graphs obtained by optical simulation, and the luminance is numerically represented as “1” when there is no metal layer 27 m.

  Although described later in detail, in the organic EL device 200 according to this embodiment, SiN is used in the light emitting pixel 20G and the light emitting pixel 20R so that the adjustment range of the luminance is large in the light emitting pixel 20R having the longest resonant wavelength (peak wavelength). A metal layer 27m made of TiN is provided on the second insulating layer 26 made of (see FIG. 13).

  As shown in FIG. 14, in the light emitting pixel 20R, when the metal layer 27m is provided on the first insulating layer 25 functioning as a reflection enhancing layer, the optical distance from the reflection layer 14 to the metal layer 27m is approximately 52 nm. Become. The brightness at this time is about 0.7 (70%) as compared with the case where the metal layer 27 m is not provided. As described above, when the metal layer 27m is provided on the second insulating layer 26, the optical distance from the reflective layer 14 to the metal layer 27m is approximately 141 nm. The brightness at this time is about 0.5 (50%) as compared with the case where the metal layer 27 m is not provided. Similarly, when the metal layer 27m is provided immediately below the pixel electrode 31, the optical distance from the reflective layer 14 to the metal layer 27m is approximately 287 nm. The luminance at this time is about 0.97 (97%) as compared with the case where the metal layer 27 m is not provided.

  As shown in FIG. 15, in the light emitting pixel 20G, when the metal layer 27m is provided on the first insulating layer 25 functioning as a reflection enhancing layer, the optical distance from the reflection layer 14 to the metal layer 27m is approximately 52 nm. The luminance is about 0.74 (74%) as compared with the case where the metal layer 27m is not provided. As described above, when the metal layer 27m is provided on the second insulating layer 26, the optical distance from the reflective layer 14 to the metal layer 27m is about 141 nm, and the luminance is higher than that in the case where the metal layer 27m is not provided. It is about 0.67 (67%). Similarly, when the metal layer 27m is provided immediately below the pixel electrode 31, the optical distance from the reflective layer 14 to the metal layer 27m is about 206 nm, and the luminance is about 0 as compared with the case where the metal layer 27m is not provided. It is about .94 (94%). Therefore, in the organic EL device 200 of the present embodiment, by further providing the metal layer 27m as the brightness adjustment layer, the brightness of the light emitting pixel 20R decreases by about 50% as compared to the case where the metal layer 27m is not provided. The brightness of 20 G drops by about 33%.

  In the optical resonant structure of the organic EL device 200, when the optical distance from the metal layer 27m to the counter electrode 36 is D1, and the optical distance from the reflective layer 14 to the metal layer 27m is D2, D1 and D2 are When the condition of the following equation (2) is satisfied, it is considered that the phase shift between the light reflected by the counter electrode 36 and the light reflected by the reflective layer 14 is λ / 2 and the luminance is most reduced.

(M + 1/2) λ = 2D-φ (2)
m is a positive integer (m = 0, 1, 2...), λ is a resonant wavelength, D is an optical distance in the optical resonant structure, φ in the case of D 1 is an interface between the counter electrode 36 and the functional layer 35 And the phase shift at the interface between the metal layer 27m and the layer adjacent to the metal layer 27m. Further, φ in the case of D2 is a total value of the phase shift at the interface between the reflective layer 14 and the first insulating layer 25 and the phase shift at the interface between the metal layer 27m and the layer adjacent to the metal layer 27m.

  That is, the position of the metal layer 27m between the reflective layer 14 and the pixel electrode 31 is set depending on how much the luminance in the light emitting pixel 20 is reduced as compared to the case where the metal layer 27m is absent.

According to the organic EL device 200 of the second embodiment, the following effects can be obtained.
(1) The optical path length adjustment layer 28 in the light resonance structure of the light emitting pixel 20G includes the fourth insulating layer 27 b functioning as a luminance adjustment layer and the metal layer 27 m. In addition, the optical path length adjustment layer 28 in the light resonance structure of the light emitting pixel 20R includes the third insulating layer 27a functioning as a brightness adjustment layer and the metal layer 27m. Therefore, the luminance can be reduced more effectively as compared with the case where the metal layer 27m is not provided. That is, when white display is performed, the difference in the magnitude of the current supplied to the organic EL elements 30B, 30G, and 30R of the light emitting pixels 20B, 20G, and 20R can be more effectively reduced, or the current ratio can be more effectively reduced. It can be

(2) Since the metal layer 27m is made of at least one metal selected from Ti, Mo, Ta, Al, Cu, and Cr or an alloy containing the metal, a metal thin film can be formed using these metals or alloys. If it does, metal layer 27m which has light transmittance and light reflectivity which exhibits a brightness adjustment function can be constituted. In particular, by using the metal nitride (TiN) as in this embodiment, the low reflective metal layer 27m can be formed, so that the luminance is not sharply reduced and the luminance is adjusted gently. be able to.
Further, since no special metal material is used, the metal layer 27m can be formed using various materials and devices for forming the wiring structure of the element substrate 10.

  In the first and second embodiments, the light emitting pixels 20G and 20R correspond to the first pixel of the present invention, and the light emitting pixel 20B corresponds to the second pixel of the present invention.

  Next, the effect of including the brightness adjustment layer in the optical resonant structure will be more specifically described by comparing it with a comparative example and taking a comparison example. FIG. 16 is a schematic cross-sectional view showing an optical resonant structure of the organic EL device of Comparative Example 1.

(Comparative example 1)
As shown in FIG. 16, in the organic EL device 300 of Comparative Example 1, an element substrate 310 provided with light emitting pixels 20 B, 20 G, and 20 R capable of obtaining different emission colors and an element substrate 310 oppositely disposed with the resin layer 60 interposed therebetween. And the transparent sealing substrate 70. The element substrate 310 is provided on the base 10s to correspond to the reflective layer 14 and the insulating layer 326 commonly formed over the light emitting pixels 20B, 20G, and 20R, and to the light emitting pixels 20B, 20G, and 20R. The organic EL elements 30B, 30G, and 30R and the color filter 50 (filter layers 50B, 50G, and 50R) are provided. The filter layers 50B, 50G, and 50R are disposed on the sealing layer 40 covering the organic EL elements 30B, 30G, and 30R.

  Each of the organic EL elements 30B, 30G, and 30R has a functional layer 35 sandwiched between the pixel electrode 31 which is an anode and the counter electrode 36 which is a cathode. The functional layer 35 includes a hole injection layer 32, an organic light emitting layer 33, and an electron transport layer 34 stacked in order from the pixel electrode 31 side, and the functional layer 35 emits white light. White light is converted into desired color light by transmitting through the filter layers 50B, 50G, and 50R, and is extracted from the sealing substrate 70 side.

The light resonance structure in the organic EL device 300 of the comparative example 1 has the light of the resonance wavelength (peak wavelength) by making the thicknesses of the pixel electrodes 31B, 31G, 31R different for each of the light emitting pixels 20B, 20G, 20R. It is taking out. The insulating layer 326 between the reflective layer 14 and the pixel electrode 31 can be formed using SiN or SiO ₂ . In the case of extracting light of the same resonant wavelength as that of the organic EL device 100 according to the above embodiment, for example, the target thickness of the insulating layer 326 in the case of forming the insulating layer 326 using SiN is 73 nm. In this case, the film thickness of the pixel electrode 31B is 20 nm, the film thickness of the pixel electrode 31G is 57 nm, and the film thickness of the pixel electrode 31R is 112 nm. That is, the optical resonant structure of Comparative Example 1 does not include the luminance adjustment layer.

Example 1
The optical resonant structure including the brightness adjustment layer of Example 1 is the one described in the organic EL device 100 of the first embodiment, and the film thickness of the aim of the first insulating layer 25 made of SiO ₂ is 35 nm and SiN consisting aim of the thickness of the second insulating layer 26 is 45 nm, made of SiO _2, the thickness of the aim of the third insulating layer 27a is 56 nm, the aim of the thickness of the fourth insulating layer 27b is 44 nm, a pixel electrode made of ITO The target film thickness of 31B, 31G, 31R is 20 nm.

(Example 2)
The optical resonant structure including the brightness adjustment layer of the second embodiment is the one described in the organic EL device 200 of the second embodiment, and the target film thickness of the first insulating layer 25 made of SiO ₂ is 35 nm and SiN The target thickness of the second insulating layer 26 is 45 nm, the target thickness of the metal layer 27 m of TiN is 2 nm, the target thickness of the third insulating layer 27 a is 56 nm, the fourth insulating layer is SiO ₂ The target film thickness of 27b is 44 nm, and the target film thickness of pixel electrodes 31B, 31G, 31R made of ITO is 20 nm.

  In Comparative Example 1, Example 1, and Example 2, the configuration of the functional layer 35 between the pixel electrodes 31B, 31G, and 31R and the counter electrode 36 is the same.

FIG. 17 is a table showing the evaluation results of Comparative Example 1 and Example 1 and Example 2, and FIG. 18 is a graph showing the current ratio in the light emitting pixel of Comparative Example 1 and Example 1 and Example 2.
As shown in FIG. 17, the consumption current [mA] in the light emitting pixels 20B, 20G, and 20R when white is displayed is as follows.
In Comparative Example 1, blue (B) was 48.5 mA, green (G) was 16.1 mA, and red (R) was 15.6 mA.
In Example 1, blue (B) was 39.3 mA, green (G) was 18.3 mA, and red (R) was 17.9 mA.
In Example 2, blue (B) was 38.8 mA, green (G) was 28.6 mA, and red (R) was 42.8 mA.
That is, in the case of displaying white with desired chromaticity, in Comparative Example 1, it was necessary to flow twice or more current to the light emitting pixel 20B with respect to the other light emitting pixels 20G and 20R. On the other hand, in Example 1 and Example 2, the current supplied to the light emitting pixel 20B decreases, and the current supplied to the light emitting pixels 20G and 20R increases. Thereby, as shown in FIG. 18, the current ratio in Comparative Example 1 was B: G: R = 0.6: 0.2: 0.19 ≒ 3: 1: 1, but in Example 1, , B: G: R = 0.52: 0.24: 0.24 2 2: 1: 1, Example 2 B: G: R = 0.35: 0.26: 0.39 1 1: It was 1: 1. That is, by forming the optical path length adjustment layer 28 so as to include the luminance adjustment layer, it is possible to reduce the difference in current consumption between the light emitting pixels 20B, 20G, and 20R, or make the current ratio uniform.

  Further, as shown in FIG. 17, the luminance life (LT80 (H)), which indicates the current application time at which the luminance is 80% of the initial luminance when white light is emitted, is obtained in Comparative Example 1 and Example 1. It is almost the same, and in Example 2, the luminance life is shorter than that in Example 1 due to the increase in current consumption. On the other hand, when Δu′v ′ is determined based on the CIE 1976 UCS chromaticity diagram as the color difference (shift in chromaticity) of white display when the luminance becomes 80% of the initial level, Comparative Example 1 is 0.041. Example 1 was 0.030, Example 2 was 0.010, and Example 2 was the most preferable state. That is, by making the current ratio in the light emitting pixels 20B, 20G, and 20R uniform, it is possible to maintain white display with desired chromaticity even if the luminance in white display decreases.

Third Embodiment
<Electronic equipment>
Next, an example of an electronic device to which the organic EL device 100 of the present embodiment is applied will be described with reference to FIG. FIG. 19 is a schematic view showing a head mounted display as an electronic device.

  A head mount display (HMD) 1000 mounts a pair of optical units 1001L and 1001R and a pair of optical units 1001L and 1001R for displaying information corresponding to the left and right eyes on the head of the user. And a power supply unit, a control unit (not shown), and the like. Here, since the pair of optical units 1001L and 1001R have a symmetrical configuration, the optical unit 1001R for the right eye will be described as an example.

  The optical unit 1001R includes the display unit 100R to which the organic EL device 100 of the above embodiment is applied, a condensing optical system 1002, and a light guide 1003 bent in an L shape. A half mirror layer 1004 is provided on the light guide 1003. In the optical unit 1001R, display light emitted from the display unit 100R is incident on the light guide 1003 by the condensing optical system 1002, is reflected by the half mirror layer 1004, and is guided to the right eye. The display light (image) projected on the half mirror layer 1004 is a virtual image. Therefore, the user can visually recognize both the display (virtual image) by the display unit 100R and the external world beyond the half mirror layer 1004. That is, the HMD 1000 is a transmissive (see-through) projection type display device.

  The light guide 1003 is a combination of rod lenses, and forms a rod integrator. The light collecting optical system 1002 and the display unit 100R are disposed on the light incident side of the light guide 1003, and the rod lens receives the display light collected by the light collecting optical system 1002. . In addition, the half mirror layer 1004 of the light guide 1003 has an angle to reflect toward the right eye the light flux collected by the light collection optical system 1002 and totally reflected and transmitted in the rod lens. .

  The display unit 100R can display the display signal transmitted from the control unit as image information such as characters and video. The displayed image information is converted by the focusing optical system 1002 from a real image to a virtual image.

  As described above, the left-eye optical unit 1001L also has the display unit 100L to which the organic EL device 100 of the above embodiment is applied, and the configuration and function are the same as the right-eye optical unit 1001R. is there.

  According to this embodiment, since the organic EL device 100 of the above embodiment is applied as the display units 100L and 100R, it has high reliability quality in which chromaticity deviation in white display is unlikely to occur even in long-term use. A see-through HMD 1000 can be provided.

  The HMD 1000 to which the organic EL device 100 of the above embodiment is applied is not limited to the configuration including the pair of optical units 1001L and 1001R corresponding to both eyes, and may be configured to include one optical unit 1001R, for example. It is also good. Further, the present invention is not limited to the see-through type, and may be an immersive type in which the display is visually recognized in the state of blocking external light. In addition, the organic EL device 200 of the second embodiment may be applied to the display units 100L and 100R.

  The present invention is not limited to the embodiments described above, and can be appropriately modified without departing from the scope or spirit of the invention as can be read from the claims and the entire specification, and an electro-optical device with such modifications Electronic equipment to which the electro-optical device is applied is also included in the technical scope of the present invention. Various modifications can be considered other than the above embodiment. Hereinafter, a modification is given and demonstrated.

  (Modification 1) The configuration of the insulating layer 28 in the light emitting pixel 20G is not limited to the configuration having the fourth insulating layer 27b in addition to the second insulating layer 26. For example, the third insulating layer 27a may be provided instead of the fourth insulating layer 27b. That is, the third insulating layer 27a may be formed across the light emitting pixels 20G and 20R, and the fourth insulating layer 27b may be formed corresponding to the light emitting pixel 20R.

  (Modification 2) The organic EL elements 30B, 30G, and 30R of the light emitting pixels 20B, 20G, and 20R are not limited to the configuration in which white light can be obtained from the functional layer 35. The present invention can be applied even if the corresponding color light is obtained from each of the organic EL elements 30B, 30G, and 30R. The present invention can also be applied to an organic EL device that does not have the color filter 50.

  (Modification 3) In the organic EL device 100 according to the above-described embodiment, the reflection layer is not limited to the configuration using the power supply line 14. An electrically independent reflective layer may be provided in the lower layer of the pixel electrode 31 using a material having light reflectivity separately from the power supply line 14. According to this, the reflective layer can be freely disposed to the light emitting pixels 20B, 20G, and 20R.

  (Modification 4) The electronic device to which the organic EL device 100 of the above embodiment is applied is not limited to the HMD 1000. For example, it can be used suitably for display parts, such as a head up display (HUD), an electronic view finder (EVF), and a portable information terminal.

DESCRIPTION OF SYMBOLS 10 ... Element substrate, 14 ... Power supply line as a reflection layer, 20, 20B, 20G, 20R ... Light emission pixel, 25 ... 1st insulating layer as a reflection layer, 26 ... 2nd insulation layer, 27a ... As a brightness adjustment layer Third insulating layer, 27 m: metal layer, 28: insulating layer (optical path length adjusting layer), 30, 30B, 30G, 30R: organic EL element, 31, 31B, 31G, 31R: pixel electrode, 35: functional layer, 36: counter electrode as a semi-transmissive reflective layer, 100, 200: organic EL device, 1000: head mounted display (HMD) as an electronic device.

Claims (8)

A reflective layer, a semi-transmissive reflective layer, and first and second pixels provided between the reflective layer and the semi-transmissive reflective layer, each having an optical path length adjusting layer and a light emitting functional layer;
Each of the first pixel and the second pixel has a reflection enhancing layer made of a silicon oxide film provided on the reflection layer,
The optical path length adjustment layer of the first pixel includes a luminance adjustment layer forming an interface for reflecting light in the optical path adjustment layer, and the optical path length adjustment layer of the second pixel does not include the luminance adjustment layer. ,
The consumption current in the first pixel when emitting white light by the first pixel and the second pixel is 0.455 or more and 1.10 or less with respect to the consumption current in the second pixel. Electro-optical device. Comprising red pixels, green pixels and blue pixels,
Each of the red pixel and the green pixel is the first pixel,
The blue pixel is the second pixel,
The consumption current in the red pixel when emitting white light by the red pixel, the green pixel and the blue pixel is 23.8% with respect to the total consumption current in the red pixel, the green pixel and the blue pixel. The electro-optical device according to claim 1, which is 38.8% or less. The optical path length adjustment layer includes a translucent pixel electrode,
The electro-optical device according to claim 1, wherein the brightness adjustment layer is provided between the reflective layer and the pixel electrode.   The electro-optical device according to any one of claims 1 to 3, wherein the brightness adjustment layer has a layer whose refractive index is smaller than the refractive index of an adjacent layer.   The electro-optical device according to any one of claims 1 to 3, wherein the brightness adjustment layer includes a layer having a refractive index smaller than that of an adjacent layer, and a metal layer.   6. The electro-optical device according to claim 5, wherein the metal layer is made of at least one metal selected from Ti, Mo, Ta, Al, Cu, and Cr, or an alloy containing the metal. The adjacent layer comprises a silicon nitride film,
The electro-optical device according to any one of claims 4 to 6, wherein the layer having a small refractive index is made of a silicon oxide film. An electronic apparatus comprising the electro-optical device according to any one of claims 1 to 7 .