JP2013089444A - Organic light-emitting device, manufacturing method therefor and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic light-emitting device in which light emission in an unintended area can be limited even in a micro display, and to provide a manufacturing method therefor and an electronic apparatus.SOLUTION: The organic light-emitting device includes a substrate, a plurality of first electrodes formed on the substrate, an insulation layer which covers the end of the first electrodes and is provided with openings for exposing a part of the first electrodes, second electrodes formed to face the first electrodes, and an organic light-emitting layer formed between the first electrodes and second electrodes. A part of the insulation layer overlapping the end of the first electrode has a first part, and a second part smaller in thickness than the first part in the direction perpendicular to the substrate. The second part is formed closer to the opening side than the first part.

Description

  The present invention relates to an organic light emitting device, a method for manufacturing the organic light emitting device, and an electronic apparatus.

  In recent years, a top emission type organic light-emitting device in which an organic EL (electroluminescence) element is formed on a substrate as a light-emitting element and light emitted from the light-emitting element is extracted to the opposite side of the substrate has been widely used as a display device for electronic devices. . In the top emission method, a reflective layer is formed between one substrate (for example, an anode) formed on the substrate side with a light emitting element (organic EL element) sandwiched between the substrate and the other electrode (for example, a cathode) sandwiching the light emitting element. This is a method of taking out light from the side, and is a method with high light utilization efficiency. Such an organic EL element has features such as thinness and light weight, and has been proposed for application as a direct-view display or various lighting applications.

  Currently, microdisplays with less than 1 inch diagonal have been proposed. For example, Patent Document 1 discloses an electronic viewfinder for a digital camera. When an organic EL display is applied as an application of such a micro display, it is difficult to separately coat light emitting materials of respective colors when forming a light emitting layer corresponding to RGB due to definition restrictions. It is difficult to realize a fine mask, and it is difficult to align the organic EL panel in the manufacturing process.

  Therefore, a configuration is known in which a light emitting layer common to pixels of each color is formed using a white light emitting material, and an RGB color filter is superimposed thereon to synthesize each color. In this case, a different resonant structure is formed in each pixel by changing the optical path length for each RGB using a cavity structure (for example, Patent Document 2). As a result, light having each spectrum of RGB can be generated, and light having a further enhanced spectral peak is emitted when the light passes through the color filter.

JP 2010-96800 A Japanese Patent Laid-Open No. 08-213174

When the size of the display is several inches or more, the size of the pixel electrode (anode) on the substrate side for forming each pixel is on the order of several tens μm to 100 μm, and the organic film has a thickness of 100 to 300 nm. Since the EL element was formed, it was normal that only the light emitting layer directly above the pixel electrode on the substrate side emitted light.
However, in the case of a micro display, the size of a pixel electrode for forming each pixel is on the order of several μm, and a light emitting layer having a film thickness of 100 to 300 nm is formed on such a pixel electrode. Become. For this reason, in particular, when a low voltage is applied to the pixel electrode, not only the light emitting layer directly above, but also the carriers move in the lateral direction, and the light emitting layer in the region where no pixel electrode exists also emits light. A malfunction will occur.

  The present invention has been made in view of the above-described problems of the prior art, and is an organic light emitting device capable of suppressing light emission in an unintended region even in a micro display, a method for manufacturing the organic light emitting device, and an electronic apparatus One of the purposes is to provide.

  The organic light emitting device of the present invention is provided with a substrate, a plurality of first electrodes formed on the substrate, and an opening that covers an end of the first electrode and exposes a part of the first electrode. An insulating layer, a second electrode formed to face the first electrode, and an organic light emitting layer formed between the first electrode and the second electrode, and the insulating layer The portion of the first electrode that overlaps the end portion includes a first portion and a second portion that is thinner than the first portion in a direction perpendicular to the substrate, and the second portion is It is characterized by being formed closer to the opening than the first part.

  According to this, since the film thickness around the opening of the insulating film covering the end portion of the first electrode is thinner than the other part, the film thickness of the insulating layer is reduced between the first electrode and the insulating layer. The step formed accordingly can be relaxed. As a result, the organic light emitting layer formed so as to cover the step formed between the first electrode and the insulating film between the first electrode and the second electrode is prevented from being partially formed thin. can do. As a result, when a voltage is applied between the first electrode and the second electrode, the current is prevented from flowing preferentially to the thin portion of the organic light emitting layer and becomes a leak component, thereby contributing to light emission. Current can be reduced. Thereby, current efficiency can be improved.

The second portion may be configured to surround the opening.
According to this, since the second portion surrounds the opening, the thickness of the entire periphery of the opening is thinner than the other portions, and the thickness of the insulating layer is between the first electrode and the insulating layer. Accordingly, the step around the opening formed can be relaxed.

The first portion may include a first insulating film and a second insulating film, and the second portion may include the first insulating film and not include the second insulating film.
According to this, since the film thickness of the second part is thinner than the film thickness of the first part, a step around the opening formed according to the film thickness of the insulating layer is formed between the first electrode and the insulating layer. Can be relaxed.

The insulating layer includes the first insulating film and a second insulating film stacked on the first insulating film, and the opening is provided in the first insulating film, The second insulating film may be provided with a second opening wider than the opening.
According to this, since the opening provided in the second insulating film stacked on the first insulating film is wider than the opening provided in the first insulating film, the first insulating film The thickness of the periphery of the opening provided in the substrate is reduced, and the step around the opening formed in accordance with the thickness of the first insulating film can be relaxed between the first electrode and the first insulating film.

The first insulating film and the second insulating film may be made of an inorganic material.
According to this, since the first insulating film and the second insulating film can be formed thinner than in the case of using an organic material, the periphery of the opening of the insulating layer covering the end portion of the first electrode can be formed. Suitable for reducing the level difference. Thereby, it can further reduce that an organic light emitting layer is formed thinly around the opening of an insulating layer. In addition, if the first insulating film and the second insulating film are formed of an inorganic material, the proportion of moisture contained is extremely low compared to the case where these insulating films are formed of an organic material. It can be suppressed and excellent display quality can be maintained.

Further, a reflective layer that reflects light, the plurality of first electrodes, the insulating layer, the organic light emitting layer, and the second electrode are sequentially formed on the substrate, and the first electrode The electrodes may be formed with different thicknesses for each pixel, and a plurality of openings may be formed corresponding to the first electrodes.
According to this, by forming the film thickness of the first electrode different for each pixel, light having a wavelength corresponding to the optical path length is formed for each pixel between the reflective layer and the second electrode. Injected from the respective openings.

  The method for manufacturing an organic light emitting device of the present invention includes a step of forming a first electrode on a substrate, and an end of the first electrode is covered on the first electrode and a part of the first electrode is exposed. A step of forming an insulating layer provided with an opening; a step of forming an organic light emitting layer on the insulating layer; and a step of forming a second electrode on the organic light emitting layer. The forming step includes a step of forming an opening so that the opening exposes a part of the first electrode, a portion of the insulating layer covering an end portion of the first electrode, a first portion, Forming a second portion having a thickness in a direction perpendicular to the substrate smaller than that of the first portion, and forming the second portion closer to the opening than the first portion. To do.

  According to this, the first portion and the second portion whose thickness in the direction perpendicular to the substrate is thinner than the first portion are formed in the portion covering the end portion of the first electrode, and the second portion Is formed on the opening side of the first portion, so that the film thickness around the opening of the insulating film covering the end portion of the first electrode becomes thinner than the other portions, so that the gap between the first electrode and the insulating layer is reduced. In addition, the step formed in accordance with the thickness of the insulating layer can be reduced. As a result, the organic light emitting layer formed so as to cover the step formed between the first electrode and the insulating film between the first electrode and the second electrode is prevented from being partially formed thin. can do. As a result, when a voltage is applied between the first electrode and the second electrode, the current is prevented from flowing preferentially to the thin portion of the organic light emitting layer and becomes a leak component, thereby contributing to light emission. Current can be reduced. Thereby, current efficiency can be improved.

An electronic apparatus according to the present invention includes the organic light-emitting device described above.
According to this, since the organic light emitting device capable of suppressing light emission in an unintended region even if it is a micro display, an electronic device that can perform good display can be obtained.

1 is a plan view showing an overall configuration of an organic light emitting device according to a first embodiment of the present invention. The circuit diagram which shows the whole structure of the organic light-emitting device in embodiment. It is a figure which shows the structure of a display unit pixel, Comprising: (a) is a top view, (b) is sectional drawing. The top view which shows the structure of an active matrix paying attention to 1 pixel. The fragmentary sectional view which shows the structure of an organic light-emitting device. Sectional drawing which expands and shows the principal part of the organic light-emitting device of 2nd Embodiment. The figure which shows the emission spectrum of each color obtained from the opening of the insulating film corresponding to the cathode from which film thickness differs. The figure which shows the emission spectrum obtained from the opening of the insulating layer corresponding to each sub pixel, and the emission spectrum from the organic electroluminescent light emitting layer on the opening periphery in the insulating layer with a film thickness of 50 nm. The figure which shows the emission spectrum obtained from the opening of the insulating layer corresponding to each sub pixel, and the emission spectrum from the organic electroluminescent light emitting layer on the opening periphery in the insulating layer with a film thickness of 50 nm. The figure which shows the emission spectrum obtained from the opening of the insulating layer corresponding to each sub pixel, and the emission spectrum from the organic electroluminescent light emitting layer on the opening periphery in the insulating layer with a film thickness of 50 nm. The figure which shows the emission spectrum obtained from the opening of the insulating layer corresponding to a sub pixel, and the emission spectrum from the organic electroluminescent light emitting layer on a 10 nm-thick insulating layer. The figure which shows the emission spectrum obtained from the opening of the insulating layer corresponding to a sub pixel, and the emission spectrum from the organic electroluminescent light emitting layer on a 10 nm-thick insulating layer. The figure which shows the emission spectrum obtained from the opening of the insulating layer corresponding to a sub pixel, and the emission spectrum from the organic electroluminescent light emitting layer on a 10 nm-thick insulating layer. The figure shown about the example of the electronic device provided with the organic light-emitting device of each embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

[First Embodiment]
FIG. 1 is a plan view showing an overall configuration of an organic light-emitting device according to the first embodiment of the present invention.
As shown in FIG. 1, in the organic light emitting device 100 of the present embodiment, sub pixels 3R, 3G, and 3B provided corresponding to R, G, and B are arranged in a matrix in the display region 4 on the substrate 10A. Arranged regularly. The three sub-pixels 3R, 3G, and 3B corresponding to R, G, and B constitute a display unit pixel 3 as one basic unit, and thus the display unit pixel 3 mixes RGB light. And full color display. At this time, the sub-pixels 3R, 3G, and 3B are arranged so that R, G, and B are repeatedly arranged in one direction.

FIG. 2 is a circuit diagram showing the overall configuration of the organic light-emitting device in the present embodiment.
As shown in FIG. 2, the organic light emitting device 100 of this embodiment includes a plurality of scanning lines 101, a plurality of signal lines 102 extending in a direction intersecting the scanning lines 101, and extending in parallel with the signal lines 102. A plurality of existing power supply lines 103 are arranged, and sub-pixels 3R, 3G, and 3B corresponding to R, G, and B are provided near intersections of the scanning lines 101 and the signal lines 102. It has been. These three sub-pixels 3R, 3G, and 3B are provided in this order along the extending direction of the scanning line 101.

  A data side driving circuit 90 including a shift register, a level shifter, an analog switch, and the like is connected to the signal line 102. Further, a scanning side driving circuit 80 including a shift register, a level shifter, and the like is connected to the scanning line 101.

  Each of the sub-pixels 3R, 3G, and 3B receives a switching transistor 112 to which a scanning line signal is supplied to the gate electrode via the scanning line 101, and a pixel signal supplied from the signal line 102 via the switching transistor 112. A holding capacitor 113 to be held, a driving transistor 123 to which a pixel signal held by the holding capacitor 113 is supplied to the gate electrode, and the power supply line 103 when electrically connected to the power supply line 103 via the driving transistor 123 An anode (first electrode) 16 to which a driving current is applied from a supply line 103, and an organic EL element 7 in which an organic EL light emitting layer 19 is sandwiched between the anode 16 and a cathode (second electrode) 18 are provided. Is provided.

3A and 3B are diagrams showing the structure of the display unit pixel, where FIG. 3A is a plan view and FIG. 3B is a cross-sectional view.
As shown in FIGS. 3A and 3B, the sub-pixels 3R, 3G, and 3B that constitute the display unit pixel 3 have pixel regions that are partitioned by the insulating layer 22, and each pixel region has a light-emitting region. 17. The light emitting region 17 is a region in which the cathode 18, the organic EL light emitting layer (organic light emitting layer) 19, and the anodes 16R, 16G, and 16B are overlapped and formed. In the present embodiment, the distance L1 between the sub-pixels 3R, 3G, 3B in the display unit pixel 3 is 1.5 μm. Further, the display unit inter-pixel distance L2 is larger than the inter-subpixel distance L1, and has a relationship of L1 <L2.

FIG. 4 is a plan view showing the configuration of the active matrix with a focus on one pixel.
As shown in FIG. 4, on the anodes 16R, 16G, and 16B provided corresponding to the sub-pixels 3R, 3G, and 3B, an insulating layer 22 having an opening 22A that exposes a part of the surface 161 is formed. Has been. In the insulating layer 22, the film thickness of the second part 222 existing around the opening 22 </ b> A is smaller than the film thickness of the other part (first part 221). The step formed between the insulating layer 22 and the anodes 16R, 16G, 16B existing around each opening 22A corresponds to the thickness of the second portion 222. Therefore, the level difference is smaller than that of the conventional configuration that does not include the second portion 222.

FIG. 5 is a partial cross-sectional view showing the configuration of the organic light emitting device.
The organic light emitting device 100 of the present embodiment has a top emission structure, and each of the sub-pixels 3R, 3G, and 3B in the display region 4 on the substrate 10A has an organic EL element 7 and the organic EL element 7 as shown in FIG. An active matrix substrate 10 provided with a drive circuit 8 for driving the EL element 7 to emit light, and a color filter substrate 20 disposed opposite to the active matrix substrate 10 are provided.

Each component will be specifically described below.
As shown in FIG. 5, the device layer 12 formed on the substrate 10A is a layer including a switching transistor (not shown), a drive transistor 123, a storage capacitor 113, and the like, and the drive circuit 8 is located inside the device layer 12. Is formed.
The driving transistor 123 includes a drain electrode 41d connected to the drain region of the semiconductor layer 41a formed on the substrate 10A, a source electrode 41c connected to the source region of the semiconductor layer 41a, and a gate insulating film covering the semiconductor layer 41a. And a gate electrode 41e formed on 41b. The drain electrode 41d is connected to the power supply line 103, and the source electrode 41c is formed to penetrate the cover layer 44 and the planarization layers 45 and 46 formed to cover the source electrode 41c and the drain electrode 41d. The corresponding anodes 16R, 16G, and 16B are connected through the contact holes H.
In the present embodiment, the drive transistor is a thin film transistor. However, the drive transistor may be a field effect transistor (MISFET) formed using a semiconductor substrate.

Since the organic light emitting device 100 of the present embodiment has a top emission structure, the light emitted from the organic EL element 7 is emitted between the anodes 16R, 16G, and 16B and the substrate 10A so that the emitted light is emitted from the cathode 18 side. A plurality of reflective layers 14 corresponding to the sub-pixels 3R, 3G, and 3B are formed.
The reflective layer 14 is patterned on the surface of the device layer 12 for each of the sub-pixels 3R, 3G, and 3B, and is formed of a material having a high light reflectance. Examples of the material for forming the reflective layer 14 include aluminum, silver, or a silver alloy. The reflection layer 14 reflects light emitted from the organic EL element 7 through the anodes 16R, 16G, and 16B and emitted toward the substrate 10A, and emits the light toward the cathode 18 side. The reflective layer 14 may be formed over the entire region on the surface of the device layer 12 (region excluding the contact hole H formation region).

  On the surface of the device layer 12 (flattening layer 46), anodes 16R, 16G, and 16B having different thicknesses are formed for the sub-pixels 3R, 3G, and 3B. The anodes 16R, 16G, and 16B are made of a transparent electrode film such as ITO, and all of them are formed in a region overlapping the reflective layer 14 in plan view.

The relationship between the film thicknesses Tr, Tg, and Tb in each of the anodes 16R, 16G, and 16B is as follows: film thickness Tb <film thickness Tg <film thickness Tr. Specifically, the film thickness Tr of the anode 16R corresponding to the sub-pixel 3R is 100 nm, the film thickness Tg of the anode 16G corresponding to the sub-pixel 3G is 60 nm, and the film thickness Tb of the anode 16B corresponding to the sub-pixel 3B is 20 nm. . Note that the sizes (surface areas) of the anodes 16R, 16G, and 16B having a rectangular shape in plan view are equal to each other.
On these anodes 16R, 16G, and 16B, an insulating layer 22 is formed in which an opening 22A that covers each peripheral edge (end) 162 and exposes a part of each surface 161 is provided for each pixel.

The insulating layer 22 covers the surface 12a (exposed portion) of the device layer 12 and is formed so as to partially run on the surfaces 161 of the anodes 16R, 16G, and 16B from the surface 12a, and the anodes 16R, 16G, and 16B. The peripheral edge portion 162 of this is covered. Here, although the thicknesses of the adjacent anodes 16R, 16G, and 16B are different, the thickness of the insulating layer 22 formed between the adjacent sub-pixels 3R, 3G, and 3B is constant, and the insulating layer in this embodiment The film thickness of 22 is 20 nm. A step Q1 corresponding to the film thickness of the anodes 16R, 16G, and 16B occurs between the surface 12a of the device layer 12 and the surface 161 of each of the anodes 16R, 16G, and 16B. Thus, the insulating layer 22 exists.
In this specification, “constant, the same, and equal” includes errors that occur in the manufacturing process.

  The insulating layer 22 is formed so as to cover the ends of the anodes 16R, 16G, and 16B, and has an opening 22A that partially exposes the central side of each surface 161 of the anodes 16R, 16G, and 16B. ing. Of the insulating layer 22, the overlapping portion (portion) 220 that overlaps with the end portions (peripheral portion 162) of the anodes 16R, 16G, and 16B in a plan view can reliably cover the edge portions of the anodes 16R, 16G, and 16B. And a second portion 222 having a thickness smaller than that of the first portion 221, and the thickness is reduced toward the opening 22A. The second portion 222 existing on the opening 22A side of the first portion 221 has a width that can secure a predetermined light emitting region, and is formed in a frame shape along the inner peripheral surface of the first portion 221. is there.

The film thickness of the first portion 221 constituting the overlapping portion 220 is 1 nm or more and less than 20 nm, and the film thickness of the second portion 222 is 50 nm or more. Insulating layer 22 is formed using an inorganic material, for example, from one of _SiO 2, SiN, SiON.
The organic EL light emitting layer 19 is formed so as to cover the insulating layer 22 and the surface 161 of the anodes 16R, 16G, and 16B exposed from the openings 22A.

  In addition, since the reflective layer 14 cannot be formed in the connection region for contacting the anodes 16R, 16G, and 16B and the drive circuit 8, a resonance structure cannot be obtained. For this reason, the insulating layer 22 covers the organic EL light emitting layer 19 existing on the connection region so as not to emit light.

  From the anode 16R, 16G, 16B side, for example, the organic EL light emitting layer 19 includes a hole injection layer (HIL), a hole transport layer (HTL), a red light emitting layer (R-EML), A carrier transport layer (CTL), a blue light emitting layer (B-EML), a green light emitting layer (G-EML), and an electron injection layer (EIL) are laminated in order, and configured to emit white light from the light emitting region. ing. The layer thicknesses of the plurality of stacked functional layers are the same in the RGB sub-pixels 3R, 3G, and 3B. In this embodiment, the total film thickness of the organic EL light emitting layer 19 is 100 nm.

  In addition, each functional layer which comprises the organic EL element 7 is not limited to this, It serves as the structure by which the positive hole injection layer and the positive hole transport layer were made into the same layer, and all the functional layers of the organic EL light emitting layer 19 Other configurations such as other configurations may be used.

  The cathode 18 is formed on the entire surface of the organic EL light emitting layer 19 using a material having transflective properties. The above-described anode 16 is formed of a material having conductivity and light transmission. However, the cathode 18 existing in the optical path is formed of a metal material thin enough to transmit light, for example, or light transmission. It is formed with the material (material which has transflective property) provided with both the property and light reflectivity. As a result, the light reflected by the reflective layer 14 passes through the anode 16 and enters the cathode 18, a part of which is reflected toward the anode 16, and is reflected by the reflective layer 14 again. As a result, light having a wavelength corresponding to the optical path length between the reflective layer 14 and the cathode 18 resonates between the reflective layer 14 and the cathode 18, and the resonated light is emitted from the cathode 18 side. Become. The cathode 18 of the present embodiment is configured with a film thickness of 10 to 15 nm by a co-evaporated thin film of magnesium and silver.

  The color filter substrate 20 opposed to the active matrix substrate 10 includes sub-pixels in which the R filter 2R, the G filter 2G, and the B filter 2B partitioned by a light shielding film 21 on a transparent substrate 20A such as a glass substrate correspond to each color. The filters 2R, 2G, and 2B are formed so as to conform to the arrangement of 3R, 3G, and 3B, and are arranged so as to overlap the light emitting regions of the sub-pixels 3R, 3G, and 3B. The surface area of each filter 2, 2, 2 is equal to the opening area of the opening 22 </ b> A of the insulating layer 22.

  The light emitted from the light emitting regions of the sub-pixels 3R, 3G, and 3B is converted into R light, G light, and B light that are further optimized by the filters 2R, 2G, and 2B, respectively. Accordingly, light of a color corresponding to the brightness of each light emitting area is emitted from each filter 2R, 2G, 2B, thereby forming each sub pixel 3R, 3G, 3B, and displaying a color image.

  In the organic light emitting device 100 of the present embodiment, anodes 16R, 16G, and 16B having different film thicknesses are formed in RGB, which are the three primary colors of light, on the substrate 10A side where the white organic EL light emitting layer 19 is formed. . In this way, by forming the anodes 16R, 16G, and 16B having different thicknesses for the sub-pixels 3R, 3G, and 3B, different optical resonator structures can be formed between the reflective layer 14 and the cathode 18, respectively. it can. As a result, light having a wavelength corresponding to the optical path length between the reflective layer 14 and the cathode 18 resonates between the reflective layer 14 and the cathode 18, and the resonated light is emitted from the cathode 18 side. . In this way, three different emission spectra corresponding to RGB are obtained from the white organic EL light emitting layer 19.

  In the case of a resonator structure having anodes 16R, 16G, and 16B having different thicknesses for each of the sub-pixels 3R, 3G, and 3B as in the present embodiment, each surface 161 of the anodes 16R, 16G, and 16B and the device layer 12 are provided. A step Q1 corresponding to the film thickness of the anodes 16R, 16G, and 16B occurs between the surface 12a. Therefore, when the organic EL light emitting layer 19 is uniformly formed on the substrate 10A on which such a step exists, the thickness of the organic EL light emitting layer 19 in the portion other than the step Q1 is shaded. There are cases where the film thickness becomes thinner than that of the part. In this case, when an electric field is applied between the anode 16 and the cathode 18, current flows preferentially through the thin portion of the organic EL light emitting layer 19. Since this becomes a so-called leak component and becomes a current that does not contribute to light emission necessary for display, current efficiency is lowered. This leak current (leak component) tends to occur particularly when a low voltage is applied between the anodes 16R, 16G, and 16B and the cathode 18.

  Therefore, the insulating layer 22 is formed so as to cover the step Q1 formed at the peripheral portions of the anodes 16R, 16G, and 16B. Since the insulating layer 22 covers at least the tip of the anode, the influence of the step Q1 is mitigated. As a result, the portion where the organic EL light emitting layer 19 and the anode 16 are in contact with each other is flattened, so that current is prevented from preferentially flowing through the portion of the organic EL light emitting layer 19 where the film thickness is reduced. Can be increased.

  However, when the insulating layer 22 is provided so as to cover the step Q1 generated at the peripheral portions of the anodes 16R, 16G, and 16B as described above, the anodes 16R, 16G, and 16B and the insulating layer are also provided on the opening 22A side of the insulating layer 22. A step Q <b> 2 corresponding to the film thickness of the insulating layer 22 is formed between them. Therefore, when the organic EL light emitting layer 19 is uniformly formed in a state where such a step Q2 exists, the film thickness of the organic EL light emitting layer 19 in that portion is different from that of the step Q2. It becomes a thin film thickness compared with the part. This problem is particularly noticeable in a micro display having a narrower pixel pitch (distance between sub-pixels L1, distance between display unit pixels L2) than a normal size display. In this case as well, there is a problem in that current flows preferentially through a part of the organic EL light emitting layer 19 that has been thinned as described above, causing the organic EL light emitting layer 19 on the insulating layer 22 to emit light, resulting in a decrease in current efficiency. Occurs. Further, when the resonator structure is provided as in the present embodiment, the light emitted from the organic EL light emitting layer 19 on the insulating layer 22 is the distance between the cathode 18 and the reflective layer 14 formed thereon. Unlike the other portions, (light path length) is different, and light of an unintended spectrum is emitted around the sub-pixels 3R, 3G, 3B, and pure color light cannot be obtained. A micro display with a sub-pixel area smaller than a normal size display emits light at the periphery of the sub-pixel as described above, and emits light of a color different from the intended light emission from the entire sub-pixel. Is a large percentage. This causes color misregistration.

  Therefore, in order to prevent partial thinning of the organic EL light-emitting layer 19 due to such a step Q2, in this embodiment, the film thickness of the peripheral portion of the opening 22A of the insulating layer 22 is thinner than other portions. By forming, the step Q2 generated on the opening 22A side is relaxed. Here, in the overlapping portion 220 that covers the peripheral edge 162 of the anodes 16R, 16G, and 16B, the first portion 221 has a film thickness that can reliably cover the edge portions of the anodes 16R, 16G, and 16B. Since the second portion 222 located closer to the opening 22A than the portion 221 has a thinner film thickness than the first portion 221, a step Q2 formed between the first portion 221 and the anodes 16R, 16G, and 16B is formed. Relaxed and reduced.

In order to deposit the vapor deposition material of the organic EL light emitting layer 19 on the respective surfaces 161 of the anodes 16R, 16G, and 16B exposed from the opening 22A, the thinner the insulating layer 22 existing around the opening, the better. . If the insulating layer 22 around the opening 22A is thick, the vapor deposition material flying from the vapor deposition source, depending on the positional relationship with the vapor deposition source of the opening 22A, becomes the anodes 16R and 16G to be the vapor deposition surfaces inside the opening 22A. , 16B on the surface 161, the shadow of the insulating layer 22 is greatly generated. In particular, the organic EL light emitting layer 19 formed on the opening 22A is obstructed to reach a portion corresponding to the edge of the pattern shape of the insulating layer 22 (a corner portion between the surface 161 of the anodes 16R, 16G, and 16B and the insulating layer 22). The film thickness becomes non-uniform.
By reducing the film thickness of the insulating layer 22 existing around the opening 22A as in the present embodiment, it is difficult for the shadow to be generated inside the opening 22A when the organic EL light emitting layer 19 is formed by vapor deposition. The organic EL light emitting layer 19 having a uniform thickness is formed on the insulating layer 22 and the anodes 16R, 16G, and 16B.

Thereby, even when a low voltage is applied between the anodes 16R, 16G, and 16B and the cathode 18, current is prevented from preferentially flowing through a part of the organic EL light emitting layer 19. As a result, leakage current that does not contribute to light emission can be reduced, so that current efficiency can be increased.
Therefore, even in the case of a fine electrode structure such as a micro display, it is possible to suppress light emission in an unintended region around the subpixel, and pure RGB light can be obtained.

[Second Embodiment]
Next, the organic light emitting device of the second embodiment will be described.
The basic configuration of this embodiment is the same as that of the first embodiment, but differs in the configuration of the insulating film. Therefore, in the following description, it demonstrates centering on a different location from previous embodiment, and abbreviate | omits description about a common location.

FIG. 6 is an enlarged cross-sectional view illustrating a main part of the organic light emitting device according to the second embodiment.
As shown in FIG. 6, the organic light emitting device 200 of this embodiment includes an insulating layer 52 having a stacked structure. The insulating layer 52 includes a first insulating film 53 and a second insulating film 54 stacked thereon, and has a plurality of openings 52A formed corresponding to the sub-pixels 3R, 3G, and 3B. .

  The first insulating film 53 is formed so as to cover the surface 12a of the device layer 12 and the peripheral edges 162 of the anodes 16R, 16G, and 16B having different film thicknesses, and the second insulating film 54 is formed of the first insulating film 53. Is laminated on the first insulating film 53 with an opening 54 </ b> A exposing a part 53 a (peripheral edge of the opening 52 </ b> A). Therefore, a two-layer structure of the first insulating film 53 and the second insulating film 54 is formed on the peripheral edge portion 162 of the anodes 16R, 16G, and 16B. Here, the laminated portion of the first insulating film 53 and the second insulating film 54 corresponds to the first portion, and a part 53a of the first insulating film 53 exposed from the opening (second opening) 54A becomes the second portion. Correspond.

  In the present embodiment, the insulating film present on the periphery of the opening 52A in the insulating layer 22 is only the first insulating film 53, and is thinner than the thickness of the other part having the two-layer structure. Therefore, also in this embodiment, it is possible to obtain the same effect as the above embodiment.

[Reference example]
The structure of the organic EL element and the emission spectrum obtained in each subpixel will be described below.
The organic EL element 7 includes a reflective layer 14, an anode 16, an insulating layer 22, an organic EL light emitting layer 19, and a cathode 18. Of these, the organic EL light emitting layer 19 includes a hole injection layer (HIL) and hole transport. It consists of a layer (HTL), a red light emitting layer (R-EML), a carrier transport layer (CTL), a blue light emitting layer (B-EML), a green light emitting layer (G-EML), and an electron injection layer (EIL).

In this embodiment, Al is used for the reflective layer 14, SiO _{2 is used for the} insulating layer 22, ITO is used for the anodes 16R, 16G, and 16B, HI406 is manufactured by Idemitsu Kosan Co., Ltd., and HT320 is used for the hole transport layer (HTL). BH215 + RD001 made by Idemitsu Kosan Co., Ltd. for the red light emitting layer (R-EML), HT320 for the carrier transport layer (CTL) which is one of the functional layers constituting the electron transport layer, BH215 + BD102 for the blue light emitting layer (B-EML), green BH215 + GD206 was used for the light emitting layer (G-EML), and Alq ₃ (tris (8-hydroxyquinolinato) aluminum) was used for the electron injection layer (EIL).

  In the organic EL element 7 having such an element structure, only the thicknesses of the anodes 16R, 16G, and 16B are changed, and the openings 22A of the insulating layer 22 formed corresponding to the RGB sub-pixels 3R, 3G, and 3B. FIG. 7 shows emission spectra of RGB colors obtained from the above.

Table 1 shows the film thickness of each functional layer of the organic EL light emitting device.
Here, the film thicknesses of the anodes 16R, 16G, and 16B made of ITO differ for each RGB corresponding to the emission spectra of the respective colors shown in FIG. The film thickness Tr of the anode 16R is 130 nm, the film thickness Tg of the anode 16G is 70 nm, and the film thickness Tb of the anode 16B is 30 nm. The film thickness increases as it shifts to the longer wavelength side. That is, the film thickness of the anode 16R of the sub-pixel 3R is the largest. Further, the film thicknesses of the functional layers other than the anodes 16R, 16G, and 16B are equal in the sub-pixels 3R, 3G, and 3B.

By making the thicknesses of the anodes 16R, 16G, and 16B different, light having a wavelength corresponding to the optical path length between the reflective layer 14 and the cathode 18 is emitted from the sub-pixels 3R, 3G, and 3B, respectively.
In the present embodiment, the opening area of the opening 22A or the surface area of each filter 2R, 2G, 2B in the color filter substrate 20 is made different for each color so that the emission spectra from the sub-pixels 3R, 3G, 3B are equal. ing. The light emitting area of the R pixel having a large wavelength is the smallest, followed by the light emitting area of the G pixel and the light emitting area of the B pixel. As a result, the emission intensity from each of the sub-pixels 3R, 3G, 3B becomes equal, and display with a good color balance is possible.

Next, a structure in which the film thickness around the opening in the insulating film is different will be described.
Table 2 shows the difference in film thickness around the opening in the insulating film.

[Comparative example]
First, consider an example in which an insulating layer 22 having a thickness of 50 nm is formed so as to overlap the peripheral portions of the anodes 16R, 16G, and 16B in the RGB sub-pixels 3R, 3G, and 3B.
8, 9, and 10 show the emission spectrum obtained from the opening 22 </ b> A of the insulating layer 22 corresponding to each of the sub-pixels 3 </ b> R, 3 </ b> G, and 3 </ b> B, FIG.

  In the peripheral portions of the anodes 16R, 16G, and 16B, an optical path length including the thickness of the insulating layer 22 on the peripheral portion 162 is formed in addition to the thicknesses of the anodes 16R, 16G, and 16B that are different for each RGB. That is, when injected carriers spread and flow onto the organic EL light emitting layer 19 on the overlapping portion 220 and the organic EL light emitting layer 19 on the overlapping portion 220 emits light, an emission spectrum different from the emission spectrum obtained at the opening 22A. Light will be emitted.

  8 to 10, when the thickness of the overlapping portion 220 on the anodes 16R, 16G, and 16B is 50 nm, an emission spectrum emitted from a partial region of the organic EL light emitting layer 19 on the overlapping portion 220; The emission spectrum obtained from each opening 22A is shown. According to this, the emission spectrum emitted from a partial region of the organic EL emission layer 19 on the overlapping portion 220 of the anodes 16R, 16G, and 16B is obtained from the opening 22A. As a result, the light is shifted from the light emission spectrum and chromaticity from the opening 22A that should be originally obtained.

[Example]
Next, consider an example in which the thickness of the insulating layer 22 formed so as to overlap the peripheral edge 162 of the anodes 16R, 16G, and 16B in the RGB sub-pixel is thin at the periphery of the opening.
11, 12, and 13 show emission spectra obtained from the openings 22 </ b> A of the insulating layer 22 corresponding to the sub-pixels 3 </ b> R, 3 </ b> G, and 3 </ b> B and light emission from the organic EL light-emitting layer 19 on the insulating layer 22 having a thickness of 10 nm. It is a figure which shows a spectrum.
In contrast to Example 2 described above, in this example, the overlapping portion 220 of the insulating layer 22 covering the peripheral edge 162 of the anodes 16R, 16G, and 16B has a two-stage film thickness structure. In this case, the film thickness of the second portion 222 present at the periphery of the opening 22A is smaller than that of the other portions. Of the overlapping portion 220, the film thickness of the first portion 221 is 50 nm, The film thickness of the two portions 222 is 10 nm.

  11 to 13, when the thickness of the second portion 222 on the opening 22A side of the overlapping portion 220 on the anodes 16R, 16G, and 16B is 10 nm, the organic EL light emitting layer on the second portion 222 is shown. 19 shows an emission spectrum emitted from a partial region of 19 and an emission spectrum obtained from each opening 22A. According to this, the film thickness of the anode portion 16R, 16G, 16B is equal to the film thickness of the second portion 222. Even if the optical path length is formed, the difference from the optical path length in the opening 22A is smaller than the optical path length in the first portion 111. Therefore, the emission spectrum emitted from a partial region of the organic EL light emitting layer 19 on the second portion 222 is slightly shifted to the long wavelength side as compared with the emission spectrum obtained from the opening 22A, and should be originally obtained. There is little deviation from the emission spectrum and chromaticity.

  Table 3 shows CIE chromaticity coordinates calculated from each emission spectrum.

First, when calculating from each chromaticity of RGB emission obtained only from the opening 22A of the insulating layer 22 in the reference example, the NTSC ratio is 115.2%, and a color reproduction range of a wide color gamut is obtained.
On the other hand, when the film thickness of the insulating layer 22 at the periphery of the opening in the comparative example is 50 nm, the color reproduction range by each light emission of RGB obtained from the organic EL light emitting layer 19 on the opening 22A and the overlapping portion 220 is as follows. The NTSC ratio is reduced to 63% due to the light emission of the upper organic EL light emitting layer 19.
Therefore, by setting the thickness of the insulating layer 22 (second portion 222) at the periphery of the opening to 10 nm, each of RGB obtained from the organic EL light emitting layer 19 on the opening 22A and the overlapping portion 220 (second portion 222) is obtained. The NTSC ratio of the color reproduction range by light emission can be improved to 92.8%.

(Electronics)
Next, an example of an electronic apparatus provided with the organic light emitting device of the embodiment will be described.

  FIG. 14A is a perspective view showing an example of a mobile phone. In FIG. 14A, reference numeral 1000 denotes a mobile phone body (electronic device), and reference numeral 1001 denotes a display unit including an organic light emitting device.

  FIG. 14B is a perspective view showing an example of a wristwatch type electronic device. In FIG. 14B, reference numeral 1100 indicates a watch body (electronic device), and reference numeral 1101 indicates a display unit provided with an organic light emitting device.

  FIG. 14C is a perspective view illustrating an example of a portable information processing apparatus such as a word processor or a personal computer. 14C, reference numeral 1200 denotes an information processing device (electronic device), reference numeral 1202 denotes an input unit such as a keyboard, reference numeral 1204 denotes an information processing body, and reference numeral 1206 denotes a display unit including an organic light emitting device.

  Since the electronic devices shown in FIGS. 14A to 14C are provided with the organic light emitting device described in the previous embodiment, the electronic devices have good display characteristics.

  In addition to the above, the electronic devices include engineering workstations (EWS), pagers, televisions, viewfinder type or monitor direct view type video tape recorders, electronic notebooks, electronic desk calculators, car navigation devices, POS terminals, A touch panel, a head mounted display (HMD), etc. can be mentioned.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  3 ... Pixel, 10A ... Substrate, 14 ... Reflective layer, 16 ... Anode (first electrode), 18 ... Cathode (second electrode), 19 ... Organic EL light-emitting layer (organic light-emitting layer), 22, 52 ... Insulating layer, 22A, 22R, 52A, 221a, 222a ... opening, 53 ... insulating film, 53 ... first insulating film, 54 ... second insulating film, 54A ... opening (second opening), Tb, Tg, Tr ... film thickness, DESCRIPTION OF SYMBOLS 100, 200 ... Organic light-emitting device, 111, 221 ... 1st part, 162 ... Peripheral part (end part), 220 ... Overlapping part (part), 221 ... 1st part, 222 ... 2nd part, 1000 ... Mobile phone main body (Electronic equipment), 1100 ... Clock body (electronic equipment), 1200 ... Information processing apparatus (electronic equipment)

Claims (8)

A substrate,
A plurality of first electrodes formed on the substrate;
An insulating layer provided with an opening that covers an end of the first electrode and exposes a part of the first electrode;
A second electrode formed to face the first electrode;
An organic light emitting layer formed between the first electrode and the second electrode,
The portion of the insulating layer that overlaps the end portion of the first electrode has a first portion and a second portion that is thinner than the first portion in a direction perpendicular to the substrate,
The organic light emitting device, wherein the second portion is formed closer to the opening than the first portion. The organic light-emitting device according to claim 1, wherein the second portion surrounds the opening. The first portion includes a first insulating film and a second insulating film,
The organic light-emitting device according to claim 1, wherein the second portion includes the first insulating film and does not include the second insulating film. The insulating layer includes the first insulating film and a second insulating film stacked on the first insulating film,
The opening is provided in the first insulating film,
4. The organic light-emitting device according to claim 1, wherein the second insulating film is provided with a second opening wider than the opening. 5. 5. The organic light emitting device according to claim 3, wherein the first insulating film and the second insulating film are made of an inorganic material. A reflective layer that reflects light, the plurality of first electrodes, the insulating layer, the organic light emitting layer, and the second electrode are sequentially formed on the substrate.
The first electrode is formed with a different thickness for each pixel,
The organic light-emitting device according to claim 1, wherein a plurality of the openings are formed corresponding to the first electrode. Forming a first electrode on the substrate; and forming an insulating layer provided on the first electrode with an opening that covers an end of the first electrode and exposes a part of the first electrode. When,
Forming an organic light emitting layer on the insulating layer;
Forming a second electrode on the organic light emitting layer,
The step of forming the insulating layer includes
Forming an opening such that the opening exposes a portion of the first electrode;
A portion of the insulating layer covering the end portion of the first electrode is provided with a first portion and a second portion having a thickness smaller in the direction perpendicular to the substrate than the first portion. Forming a portion closer to the opening than the first portion. A method for manufacturing an organic light-emitting device.   An electronic apparatus comprising the organic light emitting device according to any one of claims 1 to 6.

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