Electro-optical device and electronic device

Abstract

To improve the utilization efficiency of light emitted from a light-emitting layer.SOLUTION: An electro-optical device 10 includes a light-emitting element 130 in which an emitting layer 132 is sandwiched between a pixel electrode 131 and a common electrode 133, and the emitting layer 132 is in contact with a pixel separation layer 151 in an opening region Ar, a partition wall 161 that surrounds the light-emitting element 130 and the common electrode 133 in a planar view, an insulating sealing layer 152 that is insulating and transparent and covers the light-emitting element 130 and the partition wall 161, and a planarization layer 153 that is insulating and transparent and covers the sealing layer 152 and has a refractive index higher than that of the sealing layer 152, and the surface of the sealing layer 12 in the opening region in a planar view that faces the planarization layer 153 is concave in a cross-sectional view.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an electro-optical device and an electronic device. [Background technology]

[0002] For example, electro-optical devices using OLEDs as light-emitting elements are known. OLED stands for Organic Light Emitting Diode. Such light-emitting elements have a configuration in which a light-emitting layer is sandwiched between a pixel electrode and a common electrode. A known technology for such electro-optical devices includes a substrate, a plurality of light-emitting elements provided on the substrate, a plurality of filters (colored layers) provided above the plurality of light-emitting elements, and a wall portion surrounding each colored layer in a planar view, and each colored layer has a concave surface on the display surface side (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2023 / 068227 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, in electro-optical devices with small pixel sizes, it has become desirable to improve the brightness in the front direction and the light utilization efficiency, thereby reducing power consumption and extending the life of the light-emitting layer. [Means for solving the problem]

[0005] In order to solve the above problem, an electro-optical device according to one embodiment of the present disclosure includes a light-emitting element having a first electrode, a second electrode, and a light-emitting layer provided between the first electrode and the second electrode, a partition wall surrounding the light-emitting element in a planar view, a first insulating layer covering the periphery of the first electrode and having an opening region overlapping the first electrode in a planar view, an insulating second insulating layer having insulating properties and transparency and covering the light-emitting element and the partition wall, and a third insulating layer having insulating properties and transparency and covering the second insulating layer and having a refractive index higher than that of the second insulating layer, wherein the first electrode and the light-emitting layer are in contact in the opening region, and a surface of the second insulating layer in the opening region facing the third insulating layer is concave in a planar view. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a perspective view illustrating a configuration of an electro-optical device according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating an electrical configuration of an electro-optical device. [Figure 3] FIG. 2 is a diagram illustrating a configuration of a pixel circuit in an electro-optical device. [Figure 4] 5A and 5B are diagrams illustrating the operation of the electro-optical device. [Figure 5] FIG. 2 is a plan view showing a main part of a pixel portion in the electro-optical device. [Figure 6] FIG. 1 is a partial cross-sectional view schematically illustrating an electro-optical device. [Figure 7] FIG. 2 is a partial cross-sectional view illustrating an electro-optical device. [Figure 8] FIG. 2 is a partial cross-sectional view illustrating an electro-optical device. [Figure 9] FIG. 2 is a partially enlarged cross-sectional view illustrating an electro-optical device. [Figure 10] FIG. 4 is a partially enlarged cross-sectional view illustrating the path of emitted light from the electro-optical device. [Figure 11] FIG. 10 is a partially enlarged cross-sectional view illustrating an electro-optical device according to a second embodiment. [Figure 12] FIG. 4 is a partially enlarged cross-sectional view illustrating the path of emitted light from the electro-optical device. [Figure 13] FIG. 10 is a partial cross-sectional view illustrating an electro-optical device according to a first application example. [Figure 14] FIG. 10 is a partial cross-sectional view illustrating an electro-optical device according to a second application example. [Figure 15] FIG. 1 is a perspective view showing a head-mounted display using an electro-optical device according to an embodiment. [Figure 16] FIG. 2 is a diagram illustrating an optical configuration of a head-mounted display. [Figure 17] FIG. 10 is a partially enlarged cross-sectional view illustrating the path of emitted light from an electro-optical device according to a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0007] Electro-optical devices according to embodiments will be described below with reference to the drawings. Note that the dimensions and scale of each part in each drawing are appropriately different from those of the actual device. Furthermore, the embodiments described below are preferred specific examples, and therefore various technically preferable limitations are applied. However, the scope of the present disclosure is not limited to these embodiments unless otherwise specified in the following description to the effect that the present disclosure is limited.

[0008] FIG. 1 is a perspective view showing an electro-optical device 10 according to a first embodiment, and FIG. 2 is a block diagram showing the electrical configuration of the electro-optical device 10. As shown in FIG. The electro-optical device 10 is, for example, a microdisplay panel that displays color images in a head-mounted display or the like. The electro-optical device 10 includes a plurality of pixel units and a drive circuit that drives the pixel units. The pixel units and the drive circuit are integrated on a semiconductor substrate. The semiconductor substrate is typically a silicon substrate, but may be another type of semiconductor substrate.

[0009] The electro-optical device 10 is housed in a frame-shaped case 192 that opens to the display region 100. One end of an FPC board 194 is connected to the electro-optical device 10. FPC is an abbreviation for Flexible Printed Circuits. The other end of the FPC board 194 is provided with a plurality of terminals 196 for connecting to a host device (not shown). When the plurality of terminals 196 are connected to the host device, video data, synchronization signals, and the like are supplied to the electro-optical device 10 from the host device via the FPC board 194.

[0010] As shown in FIG. 2, the electro-optical device 10 includes a control circuit 30, a data signal output circuit 50, a display area 100, and a scanning line driving circuit 120. In the display area 100, m rows of scanning lines 12 are arranged along the X direction, and (3n) columns of data lines 14 are arranged along the Y direction so as to be electrically insulated from each other and from each other, where m is an integer of 2 or more, and n is an integer of 2 or more.

[0011] To generalize and explain the scanning lines 12, an integer i between 1 and m is used. To distinguish the rows of the scanning lines 12, they are sometimes referred to as rows 1, 2, 3, ..., (i-1), i, ..., (m-1), and m, from top to bottom in the figure. Similarly, an integer j between 1 and n is used to generalize and describe the data lines 14. To distinguish the columns of the data lines 14, they may be referred to as columns 1, 2, 3, ..., (3j-2), (3j-1), (3j), ..., (3n-2), (3n-1), and (3n) from left to right in the drawing.

[0012] In the display area 100, pixel units 110R that emit light in the red wavelength range, pixel units 110G that emit light in the green wavelength range, and pixel units 110B that emit light in the blue wavelength range are arranged in the following manner, corresponding to the intersections of m rows of scanning lines 12 and (3n) columns of data lines 14. The pixel unit 110R is provided corresponding to the intersection of the scanning line 12 of each row and the (3j-2)th column data line 14. The pixel unit 110G is provided corresponding to the intersection of the scanning line 12 of each row and the (3j-1)th column data line 14. The pixel unit 110B is provided corresponding to the intersection of the scanning line 12 of each row and the (3j)th column data line 14.

[0013] That is, in the display region 100, pixel units 110R, 110G, and 110B are arranged in this order along the X direction. Note that one color is expressed by additive color mixture of three pixel units 110R, 110G, and 110B that are adjacent in the X direction. Therefore, the electro-optical device 10 displays an image in which color pixels are arranged in m rows and n columns. Strictly speaking, the pixel units 110R, 110G, and 110B should be called sub-pixel units, but for convenience of explanation, they will be referred to as pixel units. Furthermore, when the pixel units 110R, 110G, and 110B are generally described without specifying the color, they may be referred to as 110.

[0014] The control circuit 30 controls each unit based on video data Vid and a synchronization signal Sync supplied from a host device (not shown). Specifically, the control circuit 30 generates various control signals to control each unit. The video data Vid specifies the gradation level of pixels in the image to be displayed, for example, using 8 bits. The synchronization signal Sync includes a vertical synchronization signal that instructs the start of vertical scanning of the video data Vid, a horizontal synchronization signal that instructs the start of horizontal scanning, and a dot clock signal that indicates the timing of one pixel of video data.

[0015] The luminance characteristics at the gradation levels indicated by the video data Vid supplied from the host device do not necessarily match the luminance characteristics of the OLED included in the pixel unit 110. Therefore, in order to cause the OLED to emit light at a luminance corresponding to the gradation levels indicated by the video data Vid, the control circuit 30 up-converts the 8 bits of the video data Vid to, for example, 10 bits and outputs the up-converted data as video data Vdata. Therefore, the 10-bit video data Vdata becomes data corresponding to the R, G, and B gradation levels specified by the video data Vid. For up-conversion, a look-up table is used that stores in advance the correspondence between 8 bits of input video data Vid and 10 bits of output video data Vdata.

[0016] The scanning line driving circuit 120 is a circuit for driving the pixel units 110 arranged in m rows (3n) columns, row by row, under the control of the control circuit 30. Specifically, the scanning line driving circuit 120 supplies scanning signals / Gwr(1), / Gwr(2), / Gwr(3), ..., / Gwr(m-1), / Gwr(m) to the 1st, 2nd, 3rd, ..., (m-1), and mth scanning lines 12 in that order. Generally, the scanning signal supplied to the i-th scanning line 12 is represented as / Gwr(i).

[0017] The data signal output circuit 50 is a circuit that outputs a data signal via the data lines 14 to the pixel units 110 located in a row selected by the scanning line drive circuit 120 under the control of the control circuit 30. The data signal is a voltage signal obtained by converting 10-bit video data Vdata into analog. That is, the data signal output circuit 50 converts one row's worth of video data Vdata corresponding to the pixel units 110 in columns 1 to (3n) in the selected row into analog data, and outputs it to the data lines 14 in columns 1 to (3n) in this order.

[0018] Although not specifically shown, a power supply circuit is provided outside the display area 100, and this power supply circuit generates power supply potentials Vel and Vct for the control circuit 30, the scanning line driving circuit 120, the data signal output circuit 50, and the OLED. In addition, in the figure, the data signals output to the data lines 14 in the 1st, 2nd, 3rd, ..., (3n-2), (3n-1), and (3n)th columns are expressed as Vd(1), Vd(2), Vd(3), ..., Vd(3n-2), Vd(3n-1), and Vd(3n), respectively. Generally, for example, the potential of the data line 14 in the (3j-2)th column is expressed as Vd(3j-2).

[0019] FIG. 3 is a diagram showing the electrical configuration of the pixel section in the electro-optical device 10. As shown in FIG. The pixel units 110R, 110G, and 110B have the same electrical configuration. Therefore, the electrical configuration of the pixel units 110R, 110G, and 110B will be described using the pixel unit 110R corresponding to the i-th row and the (3j-2)-th column as an example.

[0020] As shown in the figure, the pixel unit 110R includes, from an electrical perspective, P-channel MOS transistors 121 and 122, an OLED 130, and a capacitance element 140. In the description of the pixel section, the term "electrically" is used to refer to the multiple elements that make up the pixel section and the connection relationships between these multiple elements.

[0021] In the OLED 130 of the pixel unit 110R, a light-emitting layer 132R is sandwiched between a pixel electrode 131 and a common electrode 133. The light-emitting layer 132R emits light including the R wavelength range. The pixel electrode 131 functions as an anode, and the common electrode 133 functions as a cathode. In the OLED 130, when a current flows from the anode to the cathode, holes injected from the anode and electrons injected from the cathode recombine in the light-emitting layer 132R to generate excitons, which then emit light including the R wavelength range.

[0022] In the OLED 130 of the pixel unit 110G, a light-emitting layer 132G is sandwiched between the pixel electrode 131 and the common electrode 133. The light-emitting layer 132G emits light including a G wavelength range. In the OLED 130 of the pixel unit 110B, a light-emitting layer 132B is sandwiched between the pixel electrode 131 and the common electrode 133. The light-emitting layer 132B emits light including a B wavelength range. Each of the light-emitting layers 132R, 123G, and 132B includes at least a light-emitting functional layer that emits light of the corresponding color. The light-emitting layers 132R, 123G, and 132B may be configured to sandwich one or more organic layers separate from the light-emitting functional layer. When the light-emitting layers 132R, 132G, and 132B are generally described without specifying the color, they may be referred to as 130.

[0023] In the transistor 121 of the pixel unit 110R in the i-th row and (3j-2) column, the gate node g is connected to the drain node of the transistor 122, the source node is connected to the power supply line 116 of the potential Vel, and the drain node is connected to the pixel electrode 131 which is the anode of the OLED 130. In the transistor 122 of the pixel unit 110R in the i-th row and (3j-2)th column, the gate node is connected to the i-th row scanning line 12 and the source node is connected to the (3j-2)-th column data line 14. The common electrode 133 functioning as the cathode of the OLED 130 is connected to the power supply line 118 at a potential Vct. In addition, since the electro-optical device 10 is formed on a silicon substrate, the substrate potential of the transistors 121 and 122 is set to a potential equivalent to, for example, the potential Vel.

[0024] 3 is electrically common to the pixel units 110G and 110B, except that the light-emitting layer 132R is replaced by the light-emitting layer 132G in the pixel unit 110G and by the light-emitting layer 132B in the pixel unit 110B.

[0025] The X direction is the extension direction of the scanning lines 12 in the electro-optical device 10, which corresponds to the horizontal direction on the display screen. The Y direction is the extension direction of the data lines 14, which corresponds to the vertical direction on the display screen. The two-dimensional plane defined by the X and Y directions is the substrate surface of the semiconductor substrate. The Z direction is perpendicular to the X and Y directions and corresponds to the emission direction of light emitted from the OLED 130. The Z direction can also be referred to as the display surface side. In this description, a planar view refers to viewing the semiconductor substrate from the opposite direction to the Z direction, and a cross-sectional view refers to viewing the semiconductor substrate by cutting it in the direction perpendicular to the substrate surface.

[0026] FIG. 4 is a timing chart for explaining the operation of the electro-optical device 10. As shown in FIG. In the electro-optical device 10, m scanning lines 12 are scanned one by one during one frame (V) in the order of 1, 2, 3, ..., (m-1)) and m-th row. In detail, as shown in the figure, the scanning signals / Gwr(1), / Gwr(2), / Gwr(3), ..., / Gwr(m-1), / Gwr(m) are sequentially and exclusively set to L level by the scanning line driving circuit 120 for each horizontal scanning period (H). In this embodiment, the periods during which adjacent scanning signals / Gwr(1) to / Gwr(m) are at L level are separated in time. Specifically, after scanning signal / Gwr(i-1) changes from L level to H level, the next scanning signal / Gwr(i) goes to L level after a period. This period corresponds to the horizontal blanking interval.

[0027] In this description, the period of one frame (V) refers to the time required to display one frame of the image specified by the video data Vid. If the length of one frame (V) is the same as the vertical synchronization period, for example, if the frequency of the vertical synchronization signal included in the synchronization signal Sync is 60 Hz, it is 16.7 milliseconds, which corresponds to one cycle of the vertical synchronization signal. Furthermore, the horizontal scanning period (H) is the time interval during which the scanning signals / Gwr(1) to / Gwr(m) sequentially go to the L level, but for convenience in the figure, the start timing of the horizontal scanning period (H) is shown to be approximately the center of the horizontal blanking period.

[0028] When one of the scanning signals / Gwr(1) to / Gwr(m), for example the scanning signal / Gwr(i) supplied to the scanning line 12 in the i-th row, goes low, the transistor 122 in the pixel unit 110R in the i-th row (3j-2) column, for example, goes on. As a result, the gate node g of the transistor 121 in the pixel unit 110R is electrically connected to the data line 14 in the (3j-2)-th column.

[0029] In this description, the "on state" of a transistor means that the source node and drain node of the transistor are electrically closed, resulting in a low impedance state, and the "off state" of a transistor means that the source node and drain node are electrically open, resulting in a high impedance state. In this description, "electrically connected" or simply "connected" means a state in which two or more elements are directly or indirectly connected or coupled. "Electrically not connected" or simply "not connected" means a state in which two or more elements are not directly or indirectly connected or coupled.

[0030] During the horizontal scanning period (H) when the scanning signal / Gwr(i) is at L level, the data signal output circuit 50 converts the video data Vdata decomposed into R, G, and B into analog potentials Vd(1) to Vd(3n) and outputs them as data signals to the 1st to (3n)th data lines 14 in order. The video data Vdata decomposed into R, G, and B are primary color components of the gradation levels of the pixels in the 1st column to the i-th row (3n) column indicated by the video data Vid. For example, in the case of the (3j-2)th column, the data signal output circuit 50 converts the R gradation level R(i,j) of the pixel in the ith row and jth column indicated by the video data Vid into an analog signal potential Vd(3j-2), and outputs it as a data signal to the (3j-2)th column data line 14. Note that, in the horizontal scanning period (H) when the scanning signal / Gwr(i-1) one row before the scanning signal / Gwr(i) is at the L level, the data signal output circuit 50 converts the R gradation level R(i-1,j) of the pixel in the (i-1)th row and jth column into an analog signal potential Vd(3j-2), and outputs it as a data signal to the (3j-2)th column data line 14.

[0031] The data signal of the potential Vd(3j-2) is applied to the gate node g of the transistor 121 in the pixel unit 110R at the i-th row and the (3j-2)th column via the (3j-2)-th data line 14, and the potential Vd(3j-2) is held by the capacitance element 140. Therefore, the transistor 121 passes a current to the OLED 130 according to the voltage between the gate node and the source node. Even when the scanning signal / Gwr(i) goes to H level and the transistor 122 is turned off, the potential Vd(3j-2) is held by the capacitive element 140, and therefore a current continues to flow through the OLED 130. Therefore, in the pixel unit 110R in the i-th row and column (3j-2), the OLED 130 continues to emit light at a brightness corresponding to the voltage held by the capacitive element 140, i.e., the gradation level, until the period of one frame (V) has elapsed and the transistor 122 is turned on again and the potential of the data signal is applied again.

[0032] Although the pixel unit 110R in the i-th row and (3j-2) column has been described here, the OLEDs 130 of the pixel units 110R, 110G, and 110B in the i-th row other than the pixel unit 110R in the (3j-2) column also emit light at the luminance indicated by the video data Vdata. Also, the OLEDs 130 of the pixel units 110R, 110G, and 110B in rows other than the i-th row emit light at the luminance indicated by the video data Vdata as the scanning signals / Gwr(1) to / Gwr(m) sequentially go to L level. Therefore, in the electro-optical device 10, during a period of one frame (V), the OLEDs 130 in all pixel sections 110, 110G, and 110B from row 1, column 1 to row m (3n) column emit light at the brightness indicated by the video data Vdata, thereby displaying one frame of an image.

[0033] FIG. 5 is a plan view showing an example of the arrangement of pixel sections 110R, 110G, and 110B in the electro-optical device 10, and FIG. 6 is a cross-sectional view of the main part taken along line AA' in FIG.

[0034] As shown in FIG. 5 or as described above, the pixel units 110R, 110G, and 110B are arranged side by side in the X direction in a plan view, with this order being repeated.

[0035] 6, the substrate 102 is a semiconductor substrate made of silicon or the like. A circuit layer 143 is provided on the substrate 102. The circuit layer 143 is provided corresponding to each of the pixel sections 110R, 110G, and 110G, and is provided with elements such as transistors 121 and 122 and various wirings. An insulating layer 103 is provided on the upper layer of the substrate 102. A contact hole H2 is provided in the insulating layer 103. The contact hole H2 is filled with a connection member 147 such as tungsten.

[0036] A laminate of the reflective electrode 171 and the pixel electrode 131 is provided for each of the pixel portions 110R, 110G, and 110B. Specifically, a metal wiring layer having light reflectivity, such as Al, its alloy, or Ag, is formed on the insulating layer 103 filled with the connecting member 147. After the film formation, the metal wiring layer is in contact with the connecting member 147, and the reflective electrode 171 is provided by patterning the metal wiring layer into a rectangular shape in a plan view. A transparent conductive layer having optical transparency and conductivity, such as ITO (Indium Tin Oxide), is formed to cover the insulating layer 103 and the reflective electrode 171. After the film formation, the pixel electrode 131 is provided by patterning the transparent conductive layer so that it overlaps the reflective electrode 171 and is located inside the periphery of the reflective electrode 171 in plan view. When Al is used for the reflective electrode 171, it is preferable to provide a barrier layer of a conductive material such as TiN with a thickness of about several nm between the reflective electrode 171 and the pixel electrode 131 made of ITO.

[0037] The reflective electrode 171 is in contact with the connection member 147 , so that the pixel electrode 131 is electrically connected to the drain node of the transistor 121 included in the circuit layer 143 via the reflective electrode 171 and the connection member 147 .

[0038] A pixel separation layer 151 having transparency and insulation properties is provided so as to cover the insulating layer 103, the reflective electrode 171, and the pixel electrode 131. After this, an opening region Ar that exposes the pixel electrode 131 is provided in the pixel separation layer 151 by patterning. In detail, the opening region Ar has a rectangular shape defined by an opening end Ap in plan view as shown in Fig. 5, and is provided so as to overlap the periphery of the pixel electrode 131 in cross-sectional view as shown in Fig. 6. After patterning the pixel separation layer 151, the partition wall 161 and the upper portion 163 are provided.

[0039] FIG. 7 is a cross-sectional view showing a state in which the partition wall 161 and the upper portion 163 have been provided in the manufacturing process of the electro-optical device 10. As shown in FIG. The partition wall 161 and the upper portion 163 are provided by, for example, collective patterning. In detail, the partition wall 161 and the upper portion 163 are provided at the boundary between the adjacent pixel portions 110R, 110G, and 110B as shown by hatching in FIG. In plan view, the partition walls 161 and the upper portion 163 are provided in a lattice pattern with portions extending along the X direction and portions extending along the Y direction.

[0040] The partition wall 161 is made of a conductive metal wiring layer such as aluminum, and the upper portion 163 is made of a conductive metal wiring layer such as titanium, which has a lower etching rate than the partition wall, i.e., is made of a material that is difficult to etch. In the collective etching, etching of the partition wall 161 progresses faster than etching of the upper portion 163, so that the upper portion 163 becomes wider than the partition wall 161 in plan view, and both ends of the upper portion 163 protrude beyond the side surfaces of the partition wall 161 in cross-sectional view, forming a so-called overhang structure.

[0041] As will be described later, the side surfaces of the partition walls 161 are tapered in cross section, i.e., the width in the X or Y direction narrows toward the Z direction, which is the display surface side in the figure; however, for the sake of simplicity, the side surfaces are not shown tapered in Figures 6 and 7. The partition walls 161 extend to the outside of the display area 100 and are electrically connected to the output terminal of the power supply circuit. This allows the partition walls 161 to be maintained at the potential Vct generated by the power supply circuit. Moreover, the upper portion 163 is made of a conductive metal wiring layer, but may be made of an insulating material.

[0042] FIG. 8 is a cross-sectional view showing the manufacturing process of the electro-optical device 10 immediately after the light-emitting layer 132R is formed. The light-emitting layer 132R is formed by evaporation using an evaporation source facing upward in the drawing. Therefore, the light-emitting layer 132R is formed so as to cover the opening region Ar of the pixel separation layer 151 in the pixel section 110R, and is also formed on the upper surface of the upper portion 163. In other words, the light-emitting layer 132R is formed in the pixel section 110R so as to overlap the pixel electrode 131, using the already-provided upper portion 163 as a mask. Therefore, the light-emitting layer 132R is formed by self-alignment rather than photolithography, which eliminates the need for an exposure process using an expensive fine metal mask. At this stage, the light-emitting layer 132R is also provided on the pixel portions 110G and 110B of different colors, but will be removed by etching later.

[0043] After the light-emitting layer 132R is formed, a common electrode 133 is provided by forming a conductive layer that is transparent, reflective, and conductive. The common electrode 133 is in contact with the sidewall of the partition wall 161. Therefore, the common electrode 133 is maintained at the potential Vct via the partition wall 161. Thereafter, a sealing layer 152 is provided to cover the common electrode 133, the partition wall 161, and the upper portion 163.

[0044] At this stage, the light-emitting layer 132R, the common electrode 133, and the sealing layer 152 are provided in layers above the pixel electrode 131 in the pixel sections 110G and 110B. To ensure that the pixel unit 110G has the light-emitting layer 132G of the correct color, the sealing layer 152 in the pixel unit 110R is first protected by covering it with photoresist. After this, the sealing layer 152, common electrode 133, and light-emitting layer 132R in the pixel units 110G and 110B are removed by etching. This exposes the pixel electrodes 131 in the pixel units 110G and 110B. After this, the photoresist of the pixel section 110R is removed, and in the same manner as in the pixel section 110R, in the pixel section 110G, the G light-emitting layer 132G is formed by self-alignment using the upper portion 163 as a mask, and the common electrode 133 and the sealing layer 152 are provided in that order.

[0045] At this stage, in the pixel unit 110R, the light-emitting layer 132G, the common electrode 133, and the sealing layer 152 are provided overlapping the light-emitting layer 132R, the common electrode 133, and the sealing layer 152. In addition, in the pixel unit 110B, the light-emitting layer 132G, the common electrode 133, and the sealing layer 152 are provided overlapping on top of the pixel electrode 131. First, in the pixel unit 110G, the sealing layer 152 is covered with photoresist for protection. After this, the sealing layer 152, common electrode 133, and light-emitting layer 132G that are provided overlapping in the pixel unit 110R are removed by etching, and the sealing layer 152, common electrode 133, and light-emitting layer 132G in the pixel unit 110B are also removed by the same etching. As a result, the pixel electrode 131 in the pixel unit 110B is exposed. After this, the photoresist of the pixel section 110G is removed, and in the same manner as in the pixel section 110R, in the pixel section 110B, the B light-emitting layer 132B is formed by self-alignment using the upper portion 163 as a mask, and the common electrode 133 and the sealing layer 152 are provided in that order. At this stage, in the pixel unit 110R, the light-emitting layer 132B, the common electrode 133, and the sealing layer 152 are again provided to overlap the light-emitting layer 132R, the common electrode 133, and the sealing layer 152. In the pixel unit 110G, the light-emitting layer 132B, the common electrode 133, and the sealing layer 152 are again provided to overlap the light-emitting layer 132G, the common electrode 133, and the sealing layer 152. Therefore, in pixel unit 110B, sealing layer 152 is covered with photoresist for protection. After this, sealing layer 152, common electrode 133, and light-emitting layer 132B that are provided in overlapping relation in pixel unit 110R, and sealing layer 152, common electrode 133, and light-emitting layer 132B in pixel unit 110G are each removed by etching. As a result, in the pixel unit 110R, the sealing layer 152 is provided so as to cover the pixel electrode 131, the light-emitting layer 132R, and the common electrode 133. Similarly, in the pixel unit 110G, the sealing layer 152 is provided so as to cover the pixel electrode 131, the light-emitting layer 132G, and the common electrode 133, and in the pixel unit 110B, the sealing layer 152 is provided so as to cover the pixel electrode 131, the light-emitting layer 132B, and the common electrode 133.

[0046] The sealing layer 152 is a layer for preventing moisture from penetrating into the light-emitting layers 132R, 132G, and 132B, and is made of a single film or a multilayer film of an inorganic material such as SiN, SiON, Al2O3, etc. The sealing layer 152 is formed by sputtering, CVD, AVD, etc. as appropriate.

[0047] In the state where the light-emitting layer 132R and the common electrode 133 are provided in the pixel unit 110R, the partition wall 161 and the upper portion 163 are located higher than the common electrode 133 in a cross-sectional view, that is, located closer to the display surface in the Z direction. When the sealing layer 152 is provided so as to cover the partition wall 161, the upper portion 163, and the common electrode 133 that are positioned in this way, the upper surface 152a of the sealing layer 152 has a concave surface in a cross-sectional view, as will be described below.

[0048] 9 is a partially enlarged cross-sectional view illustrating a concave surface in the electro-optical device 10. In a cross-sectional view, the partition wall 161 and the upper portion 163 are located higher than the common electrode 133, and therefore, the upper surface 152a of the sealing layer 152 has a concave surface in a region that overlaps with the opening region Ar in a plan view. In detail, as shown in FIG. 5 or 9, when the diagonal center of the opening region Ar is Cen, in the pixel electrode 131, the distance β from the opening end Ap to the upper surface 152a of the sealing layer 152 is longer than the distance α from the diagonal center Cen to the upper surface 152a of the sealing layer 152.

[0049] A planarization layer 153 is provided to cover the sealing layer 152 having such a concave surface. The planarization layer 153 is a layer for planarizing the sealing layer 152, and is formed by depositing an inorganic material having a refractive index higher than that of the sealing layer 152. The planarization layer 153 may be formed using titanium oxide, niobium oxide, hafnium oxide, tantalum oxide, zirconium oxide, or the like. The planarization layer 153 may be formed by sputtering, CVD, AVD, vapor deposition, or the like, as appropriate. The upper surface 153a of the planarization layer 153 is planarized by, for example, CMP. Although the pixel unit 110R has been described as an example here, the upper surface 152a of the sealing layer 152 in the pixel units 110G and 110B also becomes concave in the opening region Ar.

[0050] A colored layer 180 is provided to cover the planarization layer 153. The colored layer 180 collectively refers to Cf_R provided in the pixel unit 110R, Cf_G provided in the pixel unit 110G, and Cf_B provided in the pixel unit 110B. In a plan view, the colored layer Cf_R covers the opening region Ar of the pixel unit 110R, the colored layer Cf_G covers the opening region Ar of the pixel unit 110G, and the colored layer Cf_B covers the opening region Ar of the pixel unit 110B. The colored layers Cf_R, Cf_G, ​​and Cf_B are provided by patterning a photosensitive resin containing a pigment that selectively transmits each color of light using a photolithography technique, and have the function of transmitting each color of light. Here, the red light transmitted through the colored layer Cf_R is specifically light having a wavelength of 580 nm or more and 700 nm or less. The green light transmitted through the colored layer Cf_G is specifically light having a wavelength of 500 nm or more and 580 nm or less. The blue light transmitted through the colored layer Cf_B is specifically light having a wavelength of 400 nm or more and 500 nm or less.

[0051] In this embodiment, the light-emitting layer 132R emits red light, and the red light emitted from the light-emitting layer 132R passes through the colored layer Cf_R and is then visually recognized by the user. The green light emitted from the light-emitting layer 132G passes through the colored layer Cf_G, ​​and similarly, the blue light emitted from the light-emitting layer 132B passes through the colored layer Cf_B and is then visually recognized by the user. Therefore, the purity of the color visually recognized by the user can be improved compared to a configuration in which the white light emitted from the light-emitting layers is colored by a colored layer, or a configuration in which the colored layer 180 is not included and the light emitted from the light-emitting layers 132R, 132G, and 132B is directly visually recognized.

[0052] When the colored layers Cf_R, Cf_G, ​​and Cf_B are provided so as to cover the planarizing layer 153, the configuration shown in FIG. 6 is obtained. 6, the same conductive layer as the light-emitting layers 132R, 132G, and 132B and the common electrode 133 is superimposed on the upper surface of the upper portion 163, but is spaced apart near the boundaries of the pixel portions 110R, 110G, and 100B. This space is caused by etching for the protection of the photoresist.

[0053] In order to explain the advantages of the electro-optical device 10 according to this embodiment, a comparative example according to this embodiment will be described.

[0054] FIG. 17 is a diagram showing the emission path of light in an electro-optical device according to a comparative example, taking the red pixel unit 110R as an example. In the comparative example, the upper surface 152a of the sealing layer 152 is concave in cross section in the opening region Ar, as in the embodiment. However, in the comparative example, the planarizing layer 159 is made of an organic material such as epoxy resin, rather than an inorganic material as in the embodiment. Because the photosensitive resin contained in the colored layer 180 is an organic material, it is preferable that the sealing layer 152 be made of a similar organic material in consideration of adhesion to the colored layer 180. However, the epoxy resin in the planarization layer 159 generally has a refractive index of approximately 1.5 to 1.6. In contrast, if the sealing layer 152 is made of SiN, its refractive index is approximately 1.9 to 2.0. Therefore, in the comparative example, the refractive index of the planarization layer 159 is lower than the refractive index of the sealing layer 152, and therefore the light emitted from the light-emitting layer 132 is diffused by the concave surface of the sealing layer 152, and some of the light penetrates into the colored layers other than the colored layer Cf_R.

[0055] Of the light emitted from the light-emitting layer 132R of the pixel unit 110R, light that penetrates into colored layers other than the colored layer Cf_R can be made invisible to the user by using a light-blocking layer (not shown) or the like, but the utilization efficiency of red light will decrease. Therefore, increasing the brightness of the red light requires more power, which will have a negative impact on the lifespan of the light-emitting layer 132R. Although the red pixel section 110R has been described here, the same thing occurs in the green pixel section 110G and the blue pixel section 110B.

[0056] Furthermore, in electro-optical devices in which the pixel portions 110R, 110G, and 110B are relatively large, specifically in direct-view display devices used in smartphones and the like, the upper surface 152a of the sealing layer 152 is substantially flat in the opening region. Therefore, in direct-view display devices, the emitted light travels substantially straight without being refracted at the interface between the sealing layer 152 and the planarization layer 153, and the problem of reduced light utilization efficiency does not occur. In other words, the problem of reduced light utilization efficiency due to refraction of emitted light at the interface between the sealing layer 152 and the planarization layer 153 occurs in microdisplay panels in which the pixel portion arrangement pitch is approximately several micrometers.

[0057] FIG. 10 is a diagram showing the emission path of light in the electro-optical device 10 according to the first embodiment, taking the red pixel unit 110R as an example. In the first embodiment, the planarization layer 153 is made of an inorganic material, rather than an organic material as in the comparative example. Furthermore, the inorganic material of the planarization layer 153 is made of a material with a higher refractive index than that of the sealing layer 152, for example, a Ti oxide with a refractive index of approximately 2.3 to 2.5. Therefore, in the first embodiment, the light emitted from the light-emitting layer 132 is collected by the concave surface of the sealing layer 152, and the proportion of red light passing through the colored layer Cf_R is greater than in the comparative example. Therefore, according to the present embodiment, the utilization efficiency of red light is higher than in the comparative example, and a high brightness display is possible while suppressing power consumption.

[0058] In the first embodiment, the partition wall 161 and the upper portion 163 are used when forming the light-emitting layers 132R, 132G, and 133B in a self-aligned manner, and also used as wiring for supplying a potential Vct to the common electrode 133. The concave surface on the upper surface 152a of the sealing layer 152 is formed using a point where the common electrode 133 is relatively lower than the partition wall 161 and the upper portion 163. That is, in the first embodiment, the partition wall 161 and the upper portion 163 are used for forming the light-emitting layers 132R, 132G, and 133B, for wiring to the common electrode 133, and for forming a concave surface on the upper surface 152a of the sealing layer 152. Therefore, in the first embodiment, the partition wall 161 and the upper portion 163 are effectively utilized.

[0059] In the electro-optical device 10 according to the first embodiment, the colored layer 180 is provided on the planarization layer 153 made of an inorganic material, which raises concerns that the adhesion of the colored layer 180 may be inferior to that of the comparative example. Therefore, a second embodiment that overcomes such concerns will be described.

[0060] 11 is a cross-sectional view of a main part of the electro-optical device 10 according to the second embodiment, cut in the same manner as in FIG. 6. As shown in this figure, in the second embodiment, a planarization layer 154 is provided between the planarization layer 153 and the colored layer 180. That is, in the second embodiment, two planarization layers 153 and 154 are provided between the sealing layer 152 and the colored layer 180. The interface between the planarizing layers 153 and 154 is substantially parallel to the substrate surface. That is, the distance from the center Cen of the opening region Ar to the interface is substantially the same as the distance from the opening edge Ap of the opening region Ar.

[0061] In the second embodiment, the planarization layer 153 is the same as in the first embodiment, but the planarization layer 154 is made of an organic material such as epoxy resin. If the sealing layer 152 is made of SiN, its refractive index is approximately 1.9 to 2.0; if the planarizing layer 153 is made of Ti oxide, its refractive index is approximately 2.3 to 2.5; and if the planarizing layer 154 is made of epoxy Ti oxide, its refractive index is approximately 1.5 to 1.6.

[0062] FIG. 12 is a diagram showing the emission path of light in the electro-optical device 10 according to the second embodiment, taking the red pixel unit 110R as an example. In the second embodiment, as in the first embodiment, light emitted from the light-emitting layer 132 is collected by the concave surface of the sealing layer 152. In the second embodiment, the refractive index of the planarization layer 154 made of an organic material is lower than the refractive index of the planarization layer 153 made of an inorganic material, so light is diffused by refraction at the interface between the planarization layers 153 and 154. Therefore, in the second embodiment, the utilization efficiency of red light is lower than in the first embodiment, but since the light has been collected by the concave surface, the utilization efficiency of red light is higher than in the comparative example. Although the red pixel section 110R has been described here, the same applies to the green pixel section 110G and the blue pixel section 110B, and the utilization efficiency of green and blue color light is improved compared to the comparative example.

[0063] In the second embodiment, the colored layer 180 is provided on the planarization layer 154 made of an organic material, so that it is possible to dispel the concern that the adhesion of the colored layer 180 is inferior to that of the comparative example.

[0064] The above-described first and second embodiments (hereinafter referred to as "embodiments, etc.") can be modified or applied in various ways as follows.

[0065] FIG. 13 is a partial cross-sectional view showing a main part of an electro-optical device 10 according to a first application example. In the first application example, the pixel units 110R, 110G, and 110B are provided with an optical resonance structure corresponding to the color. The optical resonance structure refers to a structure in which, when the optical distance between the reflective surface of the common electrode 133 and the reflective surface of the reflective electrode is Lr in the pixel unit 110R, Lg in the pixel unit 110G, and Lb in the pixel unit 110B, the optical distances Lr, Lg, and Lb are set to distances corresponding to the wavelengths of the respective colors. Specifically, the following measures can be considered for setting the optical distances Lr, Lg, and Lb to distances corresponding to the wavelengths of the respective colors. That is, As a first measure, the film thickness of the light-emitting layers 132R, 132G, and 132B is made different for each color. As a second measure, the film thickness of the transparent pixel electrode 131 is made different for each color. As a third measure, the sum of the film thickness of the pixel electrode 131 and the film thickness of the light-emitting layer 132R, 132G, or 132B is made different for each color. The first application example is the first of these.

[0066] The optical distances Lr, Lg, and Lb are: Lr>Lg>Lb This is the relationship. In the optical resonance structure, light emitted from the light emitting layer 132R, 132B or 132B resonates due to reflection between the reflective electrode 171 and the common electrode 133, and is emitted at a resonance wavelength set corresponding to the R, G or B color. Therefore, in the first application example having an optical resonant structure, light of a wavelength corresponding to a color is intensified and emitted, which makes it possible to sharpen and increase the intensity of the spectrum and improve the purity and brightness of the color.

[0067] Although not shown in the figure, the light-emitting layer 132R, 132G, or 132B actually has a laminated structure including a hole injection layer, a hole transport layer, a light-emitting functional layer, an electron blocking layer, an electron transport layer, an electron injection layer, etc. Therefore, by adjusting the thickness of these layers for each color, the film thickness of the light-emitting layer 132R, 132G, or 132B can be made different for each color. Strictly speaking, the optical distance is the distance between the reflective electrode 171 and the common electrode 133 multiplied by the refractive index of the pixel electrode 131 and the light-emitting layer, which are the media between the reflective electrode 171 and the common electrode 133, but in the figure it is simply shown as a physical distance.

[0068] In addition, in the first application example, it is possible to omit the transparent pixel electrode 131. When the pixel electrode 131 is omitted, the optical distances Lr, Lg, and Lb can be set to distances corresponding to the wavelengths of the respective colors by the first measure described above.

[0069] FIG. 14 is a partial cross-sectional view showing a main part of an electro-optical device 10 according to a second application example. The second application example is similar to the first application example in that the pixel units 110R, 110G, and 110B have optical resonance structures corresponding to the colors. However, unlike the first application example, the second application example is different from the first application example in that the optical distances Lr, Lg, and Lb are adjusted by the film thickness of the insulating layer provided between the pixel electrode 131 and the reflective electrode 171. Note that Figure 17 shows an example in which the insulating layer provided between the pixel electrode 131 and the reflective electrode 171 is not provided in the pixel section 110B, is a single layer in the pixel section 110G, and is a two-layer structure in the pixel section 110R, in which an additional insulating layer is added to the single insulating layer provided in the pixel section 110G. As the thickness of the light-emitting layer 132 increases, the electric field weakens, and therefore a higher voltage must be applied to obtain the same brightness. However, in the second application example, the optical distances can be set to Lr > Lg > Lb while the thicknesses of the light-emitting layers 132R, 132G, and 132G are the same. Therefore, in the second application example, it is not necessary to drive the R light-emitting layer 132R, which has the longest optical distance, at a high voltage in order to improve color purity and brightness.

[0070] 13 and the second application example shown in FIG 14, elements subsequent to the planarization layer 153 are not shown. In the first and second application examples, the planarization layer 153 may be a single layer as in the first embodiment, or the planarization layers 153 and 154 may be multiple layers as in the second embodiment, between the sealing layer 152 and the colored layer 180.

[0071] In the embodiments and the like, the aperture shapes of the aperture regions Ar in the pixel units 110R, 110G, and 110B are rectangular, but are not limited to this. For example, they may be polygonal, such as hexagonal, or circular, elliptical, etc. Furthermore, the aperture areas of the aperture regions Ar may not be uniform in the pixel units 110R, 110G, and 110B, but may be different for each color. For example, the aperture areas of the aperture regions Ar may be B>G>R. The pixel units 110R, 110G, and 110B may be aligned in either the X direction or the Y direction. Alternatively, the pixel units 110R and 110B may be aligned in the same column, and the pixel unit 110G may be aligned in a column adjacent to the column of the pixel units 110R and 110B.

[0072] Furthermore, in the description of the embodiments and the like, the light emitting layers 132R, 132G, and 132B are formed in this order, but the order of film formation is not limited to this.

[0073] In this description, the pixel electrode 131 is an example of a "first electrode," the common electrode 133 is an example of a "second electrode," and the OLED 130 is an example of a "light-emitting element." The pixel separation layer 151 is an example of a "first insulating layer," the sealing layer 152 is an example of a "second insulating layer," the planarization layer 153 is an example of a "third insulating layer," and the planarization layer 154 is an example of a "fourth insulating layer."

[0074] Next, an electronic device to which the electro-optical device 10 according to the embodiment is applied will be described. The electro-optical device 10 is suitable for applications requiring small-sized pixels and high-definition displays. Therefore, a head-mounted display will be used as an example of the electronic device.

[0075] FIG. 15 is a diagram showing the appearance of a head-mounted display, and FIG. 16 is a diagram showing its optical configuration. First, as shown in Fig. 15, the head mounted display 300 has temples 310, a bridge 320, and lenses 301L and 301R in appearance similar to ordinary eyeglasses. Furthermore, as shown in Fig. 16, the head mounted display 300 is provided with an electro-optical device 10L for the left eye and an electro-optical device 10R for the right eye near the bridge 320 and behind the lenses 301L and 301R (below in the figure). The image display surface of the electro-optical device 10L is disposed on the left side in FIG. 16. As a result, the image displayed by the electro-optical device 10L is emitted in the 9 o'clock direction in the figure via the optical lens 302L. The half mirror 303L reflects the image displayed by the electro-optical device 10L in the 6 o'clock direction while transmitting light incident from the 12 o'clock direction. The image display surface of the electro-optical device 10R is disposed on the right side, opposite the electro-optical device 10L. As a result, the image displayed by the electro-optical device 10R is emitted in the 3 o'clock direction in the figure via the optical lens 302R. The half mirror 303R reflects the image displayed by the electro-optical device 10R in the 6 o'clock direction while transmitting light incident from the 12 o'clock direction.

[0076] In this configuration, a person wearing the head-mounted display 300 can observe the images displayed by the electro-optical devices 10L and 10R in a see-through state in which the images are superimposed on the outside world. Furthermore, in this head-mounted display 300, when the electro-optical device 10L displays the image for the left eye and the electro-optical device 10R displays the image for the right eye among the binocular images with parallax, the wearer can perceive the displayed image as if it had depth and a three-dimensional effect.

[0077] In addition to the head-mounted display 300, electronic devices including the electro-optical device 10 can also be applied to electronic viewfinders in video cameras and interchangeable lens digital cameras, smart watches, display units of wearable devices, light bulbs in projection projectors, and the like.

[0078] From the above-described exemplary embodiments, the following embodiments can be understood: In order to facilitate understanding of each embodiment, reference numerals in the drawings are written in parentheses for convenience, but this is not intended to limit the embodiments to those shown in the drawings.

[0079] An electro-optical device (10) according to one aspect 1 includes a light-emitting element (130) having a first electrode (131), a second electrode (133), and a light-emitting layer (132) provided between the first electrode (131) and the second electrode (133), a partition wall (161) surrounding the light-emitting element (130) in a planar view, a first insulating layer (151) covering the periphery of the first electrode (131) and having an opening region (Ar) overlapping the first electrode (131) in a planar view, and an insulating and transparent first insulating layer (151) having an opening region (Ar) overlapping the first electrode (131) in a planar view. The light-emitting element (130) includes an insulating second insulating layer (152) that covers the light-emitting element (130) and the partition wall (161), and an insulating and transparent third insulating layer (153) that covers the second insulating layer (152) and has a refractive index higher than that of the second insulating layer (152), wherein the first electrode (131) and the light-emitting layer (132) are in contact with each other in the opening region (Ar), and in a planar view, the surface of the second insulating layer (152) in the opening region (Ar) that faces the third insulating layer (153) is concave.

[0080] In the electro-optical device according to the first aspect, the refractive index of the third insulating layer covering the second insulating layer is higher than that of the second insulating layer, and the surface of the second insulating layer facing the third insulating layer is concave, so that the light emitted from the light-emitting layer is condensed, thereby improving the utilization efficiency of the light emitted from the light-emitting layer in an electro-optical device with a narrow aperture area.

[0081] In the electro-optical device (10) according to a specific aspect 2 of aspect 1, the third insulating layer (153) is made of an inorganic material.

[0082] In an electro-optical device (10) according to a third specific aspect of the first aspect, a colored layer (180) is provided on the third insulating layer (153) on the side opposite to the second insulating layer (152).

[0083] In the electro-optical device (10) according to a specific example 4 of example 3, a fourth insulating layer (154) having insulating properties and transparency is provided between the third insulating layer (153) and the colored layer (180).

[0084] In the electro-optical device (10) according to a fifth specific example of the fourth example, the fourth insulating layer (154) is made of an organic material.

[0085] In an electro-optical device (10) relating to another specific aspect 6 of aspect 1, in a planar view, the distance (β) between the first electrode and the second insulating layer (152) at the opening end (Ap) of the opening region (Ar) is longer than the distance (α) between the first electrode and the second insulating layer (152) at the center (Cen) of the opening region (Ar).

[0086] An electro-optical device (10) according to a seventh specific aspect of the first aspect includes an upper portion (163) provided on the upper surface of the partition wall (161) and protruding from the partition wall (161) in a cross-sectional view.

[0087] The electronic device (300) according to the eighth aspect includes the electro-optical device (10) according to any one of the first to seventh aspects. [Explanation of symbols]

[0088] 10...electro-optical device, 102...substrate, 103...insulating layer, 131...pixel electrode, 132, 132R, 132G, 132B...luminescent layer, 133...common electrode, 143...circuit layer, 151, 152, 153, 154...insulating layer, 161...partition wall, 163...upper part, 300...head-mounted display.

Claims

1. a light-emitting element having a first electrode, a second electrode, and a light-emitting layer provided between the first electrode and the second electrode; a partition wall surrounding the light-emitting element in a plan view; a first insulating layer covering a periphery of the first electrode and having an opening region overlapping the first electrode in a plan view; a second insulating layer having insulating and transparent properties and covering the light emitting element and the partition wall; a third insulating layer having insulating and transparent properties, covering the second insulating layer, and having a refractive index higher than that of the second insulating layer; Including, the first electrode and the light-emitting layer are in contact with each other in the opening region; In a plan view, a surface of the second insulating layer in the opening region facing the third insulating layer is concave. Electro-optical device.

2. The third insulating layer is Consisting of inorganic materials The electro-optical device according to claim 1 .

3. A colored layer is provided on the third insulating layer on the opposite side to the second insulating layer. The electro-optical device according to claim 1 .

4. A fourth insulating layer having insulating and transparent properties is provided between the third insulating layer and the colored layer. The electro-optical device according to claim 3 .

5. The fourth insulating layer is Consisting of organic materials 5. The electro-optical device according to claim 4.

6. In a plan view, the distance between the first electrode and the second insulating layer at an opening edge of the opening region is longer than the distance between the first electrode and the second insulating layer at a center of the opening region. The electro-optical device according to claim 1 .

7. an upper portion provided on an upper surface of the partition wall and protruding from the partition wall in a cross-sectional view; The electro-optical device according to claim 1 .

8. 8. An electronic device comprising the electro-optical device according to claim 1.

Images