JP7504580B2 - Electronic devices, display devices, photoelectric conversion devices, electronic equipment, lighting devices, and mobile objects - Google Patents

Description

The present invention relates to electronic devices, display devices, photoelectric conversion devices, electronic equipment, lighting devices, and mobile objects.

Organic light-emitting elements and organic photoelectric conversion elements have been proposed as electronic devices using organic layers. An organic light-emitting element is an element that has an upper electrode, a lower electrode, and an organic layer disposed between them, and emits light by exciting the organic compound contained in the organic layer. In recent years, electronic devices equipped with organic light-emitting elements have attracted attention, and display devices in particular are widely used.

Known methods for forming organic layers of organic light-emitting elements include a method for forming organic layers with different configurations for each emitted color, and a method for forming organic layers with the same configuration regardless of the emitted color. In a method for forming organic layers with the same configuration regardless of the emitted color, a continuous organic layer is typically formed across multiple light-emitting elements. Even when organic layers with different configurations are formed for each emitted color, some of the organic layers may be connected to multiple light-emitting elements.

However, in a configuration in which the organic layer is connected to multiple light-emitting elements and between multiple light-emitting elements, current leakage through the organic layer between adjacent light-emitting elements is likely to occur. Leakage current between light-emitting elements can cause unintended emission of light by light-emitting elements. Unintended emission of light by light-emitting elements narrows the color gamut that represents the expressive performance of the display device.

In addition, in photoelectric conversion elements that use an organic layer, a continuous organic photoelectric conversion layer is arranged to cover multiple lower electrodes. Leak current may occur between the multiple lower electrodes through the organic photoelectric conversion layer, resulting in noise.

A thin organic layer can reduce leakage current between the lower electrodes. However, if the organic layer is thin, leakage current is more likely to occur between the upper and lower electrodes. Patent Document 1 discloses a display device in which the thickness of the organic layer in the peripheral area of the pixel, close to the partition wall separating each pixel, is greater than the thickness of the organic layer in the center of the pixel, in order to reduce short circuits between the upper and lower electrodes.

JP 2007-73608 A

Patent Document 1 describes the relationship between the thickness of the organic layer in the center of the pixel and the thickness of the organic layer in the peripheral portion of the pixel, but does not describe the thickness of the organic layer in the direction perpendicular to the inclined portion of the partition wall separating the pixels. Simply controlling the ratio of the thickness of the organic layer in the center of the pixel to the thickness of the organic layer in the peripheral portion of the pixel is insufficient to reduce the leakage current between the upper electrode and the lower electrode caused by the thickness of the organic layer in the direction perpendicular to the inclined portion of the partition wall separating the pixels.

The present invention has been made in consideration of the above problems, and its purpose is to provide an electronic device having a plurality of first electrodes, which reduces leakage current between the plurality of first electrodes and reduces leakage current between the first electrode and the second electrode.

One embodiment of the present invention includes a plurality of first electrodes, a second electrode, a functional layer disposed between the first electrodes and the second electrodes and covering the plurality of first electrodes, and an insulating layer covering an edge of the first electrodes and having a slope on the first electrodes,
the first electrode has a first region including the end of the first electrode and covered with the insulating layer, and a second region in contact with the functional layer;
the functional layer is disposed continuously so as to cover the second regions of two adjacent first electrodes among the plurality of first electrodes and the insulating layer covering each of the two first electrodes;
an electronic device in which a layer thickness of the functional layer in the second region is smaller than a height from a top surface of the first electrode to a top surface of the insulating layer,
In a cross section perpendicular to a main surface of the first electrode, the inclined portion of the insulating layer has a gently inclined portion disposed between an upper end of the inclined portion and a lower end of the inclined portion, and a steeply inclined portion disposed between the gently inclined portion and the lower end and having an inclination angle with respect to the first electrode larger than an inclination angle of the gently inclined portion,
the steeply inclined portion has an inclination angle with respect to an upper surface of the first region of the first electrode that is greater than 50°, and the gently inclined portion has an inclination angle with respect to the first electrode that is equal to or smaller than 50°;
The electronic device is characterized in that the height of the upper surface of the functional layer in the second region of the first electrode is higher than the height of the upper end of the steeply inclined portion.

The present invention provides an electronic device having a plurality of first electrodes, which reduces leakage current between the plurality of first electrodes and reduces leakage current between the first electrode and the second electrode.

1 is a cross-sectional view illustrating a schematic configuration of an organic device according to a first embodiment of the present invention. FIG. 2 is a plan view illustrating a schematic configuration of the organic device of FIG. 1. 1A and 1B are schematic diagrams and a circuit diagram of an organic light-emitting device according to an embodiment. 11 is a diagram showing the relationship between the ratio of the distance between the openings of two adjacent first electrodes to the layer thickness of the organic layer on the first electrode, and the chromaticity of a red pixel. 1 is an enlarged cross-sectional view illustrating a schematic configuration of an organic light-emitting device according to a first embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view illustrating a schematic configuration of an organic light-emitting device according to a second embodiment of the present invention. FIG. 11 is a diagram showing the layout of components in a deposition simulation. FIG. 13 is a diagram showing a deposition simulation result. FIG. 1 is a schematic diagram illustrating an example of a display device according to an embodiment of the present invention. 1A is a schematic diagram illustrating an example of an imaging device according to the present embodiment, and FIG. 1B is a schematic diagram illustrating an example of an electronic device according to the present embodiment. 1A is a schematic diagram illustrating an example of a display device according to the present embodiment, and FIG. 1B is a schematic diagram illustrating an example of a foldable display device. 1A is a schematic diagram showing an example of an illumination device according to the present embodiment, and FIG. 1B is a schematic diagram showing an example of an automobile having a vehicle lamp according to the present embodiment. This is the relationship between the film thickness of the thinnest portion of the organic layer in the inclined portion in the direction perpendicular to the inclined portion, and the leakage current between the upper electrode and the lower electrode.

An electronic device according to one embodiment of the present invention includes a plurality of first electrodes, a second electrode, a functional layer disposed between the first electrodes and the second electrodes and covering the plurality of first electrodes, and an insulating layer covering the ends of the first electrodes and having an inclined portion on the first electrodes, the first electrodes including the ends of the first electrodes, a first region covered by the insulating layer, and a second region in contact with the functional layer, the functional layer is continuously disposed to cover the second regions of two adjacent first electrodes among the plurality of first electrodes and the insulating layer covering each of the two first electrodes, and the layer thickness of the functional layer in the second region is smaller than the height from the top surface of the first electrodes to the top surface of the insulating layer, and the functional layer in the inclined portion of the insulating layer has a layer thickness of 20 nm or more in a direction perpendicular to the inclined surface of the inclined portion.

An electronic device according to one embodiment of the present invention can be said to have an element having a first electrode, a second electrode, a functional layer disposed between the first electrode and the second electrode, and an insulating layer covering an edge of the first electrode.

As described above, in an electronic device in which the leakage current between multiple first electrodes is reduced, the thickness of the functional layer in the inclined portion of the insulating layer is 20 nm or more, thereby reducing the leakage current between the first electrode and the second electrode.

The effect of reducing leakage current due to the thickness of this functional layer is greater when the thickness of the functional layer is smaller than the height of the insulating layer covering the ends of the first electrodes, i.e., when the functional layer is thin. Also, the effect is greater when the functional layer is formed continuously in multiple elements, i.e., when the functional layer is formed in a connected manner.

When the electronic device is an organic light-emitting device, the light-emitting efficiency can be improved by making the functional layer, i.e., the organic layer, thinner. This is because the light absorbed by the organic layer can be reduced. The distance L between a pair of electrodes of the organic light-emitting device preferably satisfies the following formula (1). In the organic light-emitting device, satisfying the following formula (1) means that the optical interference between the electrodes is strengthened, and the organic light-emitting device can further improve its light-emitting efficiency. The light-emitting efficiency here can also be called extraction efficiency.
(λ/8)×(−(2φ/π)−1)<L<(λ/8)×(−(2φ/π)+1) (1)
In formula (1), λ is the wavelength of the maximum peak of the emission spectrum emitted by the light-emitting layer included in the organic layer. The maximum peak is the peak with the greatest intensity among the peaks in the emission spectrum. The peak wavelength may be the minimum wavelength among the peaks included in the emission. φ is the phase shift at the electrode. The phase shift is the phase shift that occurs when light is reflected. One of the first electrode or the second electrode may be a reflective electrode, and the other may be a light-transmitting electrode. The light-transmitting electrode may be an electrode that transmits part of the light and reflects part of it.

The element of the electronic device according to one embodiment of the present invention may be an organic light-emitting element. When the element is an organic light-emitting element, the functional layer may be an organic layer having a light-emitting layer. On the other hand, the element may be a photoelectric conversion element. When the element is a photoelectric conversion element, the functional layer may be an organic layer having a photoelectric conversion layer.

The first electrode has a first region that is covered by the insulating layer and includes an edge, and a second region that is not covered by the insulating layer and is in contact with the functional layer. The first region may surround the second region.

In an organic light-emitting device according to one embodiment of the present invention, the layer thickness of the organic layer 4 in the second region of the first electrode is preferably less than 100 nm. This makes it easier to achieve high brightness and increases the effect of reducing leakage current between the first and second electrodes according to the present invention.

A specific embodiment of an electronic device according to one embodiment of the present invention will be described below with reference to the accompanying drawings. Note that in the following description and drawings, common reference numerals are used to designate components common to multiple drawings. Therefore, common components will be described with mutual reference to multiple drawings, and descriptions of components with common reference numerals will be omitted as appropriate.

First Embodiment
The first embodiment is an example in which the electronic device is an organic light-emitting device. Fig. 1 is a schematic cross-sectional view of an organic light-emitting device 100 according to the first embodiment of the present invention. Fig. 2 is a top view of the organic light-emitting device 100. The cross section between A-A' in Fig. 2 corresponds to Fig. 1, and three elements 10 constitute one pixel. In this embodiment, an example of pixels in a delta arrangement is shown, but the present invention is not limited to this, and a stripe arrangement or a square arrangement may also be used.

The organic light-emitting device 100 includes a substrate 1 and a number of light-emitting elements 10 arranged on the upper surface (first surface) of the substrate 1. FIG. 1 shows three light-emitting elements 10R, 10G, and 10B out of the number of light-emitting elements 10 included in the organic light-emitting device 100. The "R" in 10R indicates that it is an element that emits red light. Similarly, 10G and 10B indicate that they emit green and blue light, respectively. In this specification, when a specific light-emitting element among the number of light-emitting elements 10 is indicated, a subscript is added after the reference number, such as light-emitting element 10 "R", and when either is acceptable, it is simply indicated as light-emitting element "10". The same applies to the other components.

The plurality of light-emitting elements 10 include, from the upper surface side of the substrate 1, a lower electrode 2 (first electrode) separated for each light-emitting element by an insulating layer 3, an organic layer 4 including a light-emitting layer covering the lower electrode 2 and the insulating layer 3, and an upper electrode 5 (second electrode) covering the organic layer 4. The organic light-emitting device 100 of this embodiment is a top-emission type device that extracts light from the upper electrode 5. Furthermore, the organic light-emitting device 100 includes a protective layer 6 arranged to cover the upper electrode 5, and a plurality of color filters 7 arranged on the protective layer 6 to correspond to each of the plurality of light-emitting elements 10. In this embodiment, the organic layer 4 emits white light, and the color filters 7B, 7G, and 7R separate the white light emitted from the organic layer 4 into each of the RGB lights. The color filters may be color conversion layers that absorb light from the organic layer and convert it into another color.

In this specification, "top" and "bottom" refer to the top and bottom in FIG. 1. The surface of the main surface of the substrate 1 on which the lower electrode 2 and the like are arranged is called the "top" surface. Furthermore, "height" refers to the distance upward from the top surface (first surface) of the substrate 1. It is also possible to specify a portion parallel to the top surface (first surface) of the substrate 1 and specify the "height" based on this specified standard.

In FIG. 1, the reference numeral 1 is abbreviated to substrate, but it may be an insulator disposed between the first electrode and a driving circuit including a transistor connected to the first electrode. Examples of insulators include an interlayer insulating layer made of inorganic materials such as silicon oxide and silicon nitride, and organic materials such as polyimide and polyacrylic. The initial insulating layer is sometimes called a planarization layer for the purpose of reducing unevenness on the surface on which the first electrode is formed.

The lower electrode 2 may be made of a metal material having a reflectance of 80% or more for the emission wavelength of the organic layer 4. For example, metals such as Al and Ag, or alloys of these metals with Si, Cu, Ni, Nd, etc. added thereto, may be used for the lower electrode 2. Here, the emission wavelength refers to the spectral range of the light emitted from the organic layer 4. If the reflectance of the lower electrode 2 for the emission wavelength of the organic layer 4 is high, the lower electrode 2 may have a laminated structure including a barrier layer. The material of the barrier layer may be a metal such as Ti, W, Mo, Au, or an alloy thereof. The barrier layer may be a metal layer disposed on the upper surface of the lower electrode. The upper surface of the lower electrode 2R is the reflective surface 12R. The reflective surface may reflect the emission from the organic layer. Similarly, the other pixels have 12G and 12B.

The insulating layer 3 may cover the end of the lower electrode and be disposed between the lower electrode and the functional layer. The lower electrode may have a first region covered by the insulating layer and a second region that is not covered by the insulating layer and is covered by the organic layer. The second region may be said to be in contact with the organic layer. The second region is also called an opening. This is because, in a top view, the second region can be seen as a recess formed by the insulating layer. The second region is the light-emitting region of each light-emitting element 10. In other words, the shape of the light-emitting region in a top view may be the shape of the insulating layer. The insulating layer is not limited to the shape shown in FIG. 1 as long as it has the role of separating the first electrodes of each light-emitting element.

The insulating layer 3 may have a sloped portion at its upper portion. The upper portion can be referred to as the side opposite the substrate or the functional layer side.

The insulating layer 3 may be formed, for example, by a chemical vapor deposition method (CVD method) or a physical vapor deposition method (PVD method). The insulating layer 3 may be composed of, for example, silicon nitride (SiN), silicon oxynitride (SiON), silicon oxide (SiO), or the like. The insulating layer 3 may also be a laminated film of these materials. The inclination angle of the inclined portion of the insulating layer may be controlled by the conditions of anisotropic etching or isotropic etching. The inclination angle of the insulating layer 3 may also be controlled by controlling the inclination angle of the layer immediately below the insulating layer 3. The insulating layer 3 may have unevenness on its upper surface due to processing such as etching or stacking of layers.

The organic layer 4 is disposed between the lower electrode 2 and the upper electrode 5. It may be continuously formed on the upper surface of the substrate 1 and shared by a plurality of light-emitting elements 10. It can also be said that one organic layer is shared by a plurality of light-emitting elements. The organic layer 4 may be integrally formed over the entire display area of the organic light-emitting device 100 that displays an image. The organic layer 4 may include a hole transport layer, a light-emitting layer, and an electron transport layer. Appropriate materials can be selected from the viewpoints of light-emitting efficiency, driving life, optical interference, and the like for the organic layer 4. The hole transport layer may function as an electron blocking layer or a hole injection layer, or may have a laminated structure of a hole injection layer, a hole transport layer, an electron blocking layer, and the like. The light-emitting layer may have a laminated structure of light-emitting layers that emit different colors, or may be a mixed layer in which light-emitting dopants that emit different colors are mixed.

The electron transport layer may also function as a hole blocking layer or an electron injection layer, and may have a laminated structure of an electron injection layer, an electron transport layer, and a hole blocking layer.

In addition, the region between the upper and lower electrodes, which will become the anode, and the light-emitting layer is the hole transport region, and the region between the cathode and the light-emitting layer is the electron transport region. The hole transport region and the electron transport region are collectively called the charge transport region.

The organic light-emitting device may have a configuration having multiple light-emitting layers, and may have an intermediate layer between the multiple light-emitting layers. The organic light-emitting device may have a tandem structure in which the intermediate layer is a charge generating layer. In the tandem structure, a transport layer such as a hole transport layer or an electron transport layer may be formed between the intermediate layer and the light-emitting layer.

The upper electrode 5 is disposed on the organic layer 4. It is formed continuously on a plurality of elements and is shared by a plurality of light-emitting elements 10. Like the organic layer 4, the upper electrode 5 may be integrally formed on the entire surface of the display area that displays the image of the organic light-emitting device 100. The upper electrode 5 may be an electrode that transmits at least a portion of the light that reaches the lower surface of the upper electrode 5. The upper electrode may function as a semi-transmissive reflective layer that transmits a portion of the light and reflects the other portion (i.e., semi-transmissive and reflective). The upper electrode 5 may be formed of, for example, a metal such as magnesium or silver, an alloy mainly composed of magnesium or silver, or an alloy material containing an alkali metal or an alkaline earth metal. An oxide conductor or the like may also be used for the upper electrode 5. The upper electrode 5 may also have a laminated structure as long as it has an appropriate transmittance.

The protective layer 6 may be made of a material that has low permeability to oxygen and moisture from the outside, such as silicon nitride, silicon oxynitride, aluminum oxide, silicon oxide, and titanium oxide. Silicon nitride and silicon oxynitride may be formed, for example, using a CVD method. On the other hand, aluminum oxide, silicon oxide, and titanium oxide may be formed using an atomic layer deposition method (ALD method). The combination of the constituent materials and manufacturing method of the protective layer is not limited to the above examples, but may be manufactured taking into consideration the layer thickness to be formed and the time required for it. The protective layer 6 may have a single layer structure or a multilayer structure as long as it transmits light that has passed through the upper electrode 5 and has sufficient moisture blocking performance.

The color filter 7 is formed on the protective layer 6. It may be in contact with the color filter 7R without any gap, as in the case of the color filter 7G shown in FIG. 1. Also, a color filter may be arranged so as to overlap a color filter of another color. The color filter may have a planarization layer 8 between it and the protective layer. Also, a planarization layer may be formed on the color filter. The planarization layer on the color filter may be made of the same material as the planarization layer under the color filter. For example, acrylic resin, epoxy resin, or polyimide resin may be used as the material for these planarization layers.

The layer thickness C of the organic layer 5 on the lower electrode 2R is the thickness of the organic layer in the direction perpendicular to the lower electrode, and the distance D from the opening of the lower electrode 2R to the opening of the lower electrode 2G is the shortest distance between the edges of the openings.

In an electronic device according to one embodiment of the present invention, the ratio of the distance from an opening in a first electrode to an opening in an adjacent first electrode to the layer thickness of the organic layer on the first electrode may be less than 50. An organic light-emitting device in this numerical range is a device in which light-emitting elements are arranged with such high precision that leakage current between the light-emitting elements can become an issue. The reason for this is explained below.

Figure 3 is a schematic diagram of an organic light-emitting device in which a light-emitting element 10R having a red color filter 7R and a light-emitting element 10G having a green color filter 7G are formed. The difference from Figure 1 is that the insulating layer does not have a sloped portion and does not reduce leakage current between elements. The schematic diagram shows an equivalent circuit of the light-emitting element 10R superimposed thereon. This shows the resistance value of the organic layer in Figure 3, and does not incorporate an electronic circuit. In addition, an equivalent circuit of the light-emitting element 10G is also shown to explain the leakage current between the light-emitting elements.

If the thickness of the organic layer on the lower electrode 2R is C, the distance between the openings of the lower electrode 2R and the lower electrode 2G is D, and the resistance per unit area in the thickness direction of the organic layer is r, the resistance per unit area in the horizontal direction of the organic layer is r(D/C). From this, if the current flowing through the light-emitting element 10R is I _R and the current flowing through the light-emitting element 10G is I _G , the following relationship holds:
I _G /I _R =1/(1+D/C) (2)
In other words, even if one tries to make only the red light emitting element 10R emit light, a current also flows through the green light emitting element 10G, causing it to emit light, and this is what depends on the D/C.

When the same amount of current is applied to emit light, the emission spectrum of only the red light-emitting element 10R is S _R and the emission spectrum of only the green light-emitting element 10G is S _G . In this case, the emission spectrum S _{R + G} taking into account the leakage current between the light-emitting elements is expressed by the following formula (3).
S _{R + G} = S _R + S _G (I _G /I _R ) (3)
FIG. 4 shows a graph in which the chromaticity coordinates in the CIE xy space of S _{R + G} are calculated and the x value is the vertical axis and the D/C is the horizontal axis. In FIG. 4, the change in the x coordinate means that green light is also emitted despite the intention of red light emission. That is, in FIG. 4, a low x coordinate indicates that a leak current to the adjacent pixel is generated. When D/C is 50 or more, the x value hardly changes. That is, even if there is no inclined portion of the insulating layer and the leak current between the light-emitting elements is likely to occur, when D/C is 50 or more, the leak current between the light-emitting elements may not be an issue. On the other hand, when D/C is less than 50, the x value is greatly reduced, and the decrease in the color purity of red becomes significant, so that the leak current between the light-emitting elements is an organic light-emitting device in which the light-emitting elements are arranged so finely that it may be an issue. That is, when D/C is less than 50, the effect of reducing the leak current of the organic light-emitting device according to this embodiment is particularly high.

The optical distance between a pair of electrodes of an organic light-emitting device according to one embodiment of the present invention may be a constructive interference structure. The constructive interference structure may also be called a resonant structure.

In the light-emitting element, by forming each organic layer so as to satisfy the constructive optical interference condition, the extracted light from the organic light-emitting device can be strengthened by optical interference. If the optical condition is set to strengthen the extracted light in the front direction, the light is emitted in the front direction with higher efficiency. It is also known that the half-width of the emission spectrum of the light strengthened by optical interference is smaller than that of the emission spectrum before interference. That is, the color purity can be increased. When designed for light of wavelength λ, the distance d ₀ from the emission position of the light-emitting layer to the reflection surface of the light-reflecting material can be adjusted to d ₀ = iλ/4n ₀ (i = 1, 3, 5, ...) to obtain constructive interference.

As a result, the radiation distribution of light with wavelength λ has more components in the front direction, improving the front brightness. Note that n ₀ is the refractive index at wavelength λ of the layer from the light emission position to the reflective surface.

The optical distance Lr from the light-emitting position to the reflecting surface of the light-reflecting electrode is expressed by the following formula (4), where φr [rad] is the sum of the phase shift amounts when light of wavelength λ is reflected by the reflecting surface. The optical distance L is the sum of the products of the refractive index nj of each layer of the organic layer and the thickness dj of each layer. In other words, L can be expressed as Σnj×dj, or also as n0×d0. φ is a negative value.
Lr = (2m - (φr / π)) × (λ / 4) (4)
In the above formula (4), m is an integer equal to or greater than 0. Note that when φ=-π and m=0, L=λ/4, and when m=1, L=3λ/4. Hereinafter, the condition of m=0 in the above formula will be referred to as the λ/4 interference condition, and the condition of m=1 in the above formula will be referred to as the 3λ/4 interference condition.

The optical distance Ls from the light emission position to the reflective surface of the light extraction electrode is expressed by the following formula (5), where m' is an integer of 0 or more, where φs [rad] is the sum of phase shifts when light of wavelength λ is reflected by the reflective surface.
Ls = (2m'-(φs/π)) × (λ/4) = -(φs/π) × (λ/4) (5)

Therefore, the total layer interference L is as shown in the following formula (6).
L = (Lr + Ls) = (2m - (φ/π)) x (λ/4) (6)
Here, φ is the sum (φr+φs) of the phase shifts when light of wavelength λ is reflected by the light reflecting electrode and the light extracting electrode.

In this case, in an actual light-emitting element, the above formula does not have to be strictly matched, taking into consideration viewing angle characteristics, which are in a trade-off relationship with the front extraction efficiency. Specifically, L may have an error within a range of ±λ/8 from the value that satisfies formula (6). The allowable value by which the value of L may deviate from the interference condition may be 50 nm or more and 75 nm or less.

Therefore, in the organic light-emitting device according to the present invention, it is preferable that the following formula (7) is satisfied. More preferably, L is within a range of ±λ/16 from the value that satisfies the formula (6), and it is preferable that the following formula (7') is satisfied.
(λ/8) × (4m-(2φ/π)-1) < L < (λ/8) × (4m-(2φ/π) + 1) (7)
(lambda / 16) × (8m - (4φ / π) - 1) < L < (lambda / 16) × (8m - (4φ / π) + 1) (7')
In the light-emitting device according to the present invention, it is preferable that m=0 and m'=0 in formulas (7) and (7'), that is, the optical interference condition is λ/4. In this case, formulas (7) and (7') can be expressed as formulas (8) and (8').
(λ/8)×(−(2φ/π)−1)<L<(λ/8)×(−(2φ/π)+1) (8)
(λ/16)×(−(4φ/π)−1)<L<(λ/16)×(−(4φ/π)+1) (8')
In formula (7) and formula (7'), when m=0 and m'=0, the organic layer has the thinnest film thickness in the constructive interference structure. This reduces the driving voltage of the light-emitting element, enabling light emission with higher brightness within the upper limit of the power supply voltage. When the organic layer is thin, leakage current between the upper electrode and the lower electrode is likely to occur, so by satisfying the requirements of the present invention, the effect of reducing leakage current between the upper electrode and the lower electrode is particularly large.

Here, the emission wavelength λ may be the emission wavelength at which the emission intensity is at its maximum peak. Since the maximum peak of the emission of an organic compound is generally the minimum peak in the emission spectrum, the emission wavelength λ may be the wavelength of the minimum peak.

The electronic device according to one embodiment of the present invention is a device in which the functional layer has a small thickness. More specifically, the thickness of the functional layer in the second region of the first electrode that is not covered by the insulating layer is smaller than the height of the insulating layer. The thickness of the functional layer can be estimated not only in the second region of the first electrode, but also on the upper surface of the insulating layer. In a device in which the functional layer has a small thickness and leakage current between elements is an issue, the thickness of the functional layer in the region along the inclined portion of the insulating layer is 20 nm or more. The functional layer being along the inclined portion of the insulating layer refers to a configuration in which, when a line is drawn perpendicular to the inclined portion of the insulating layer, the functional layer reaches the inclined portion of the insulating layer.

In other words, in an electronic device according to one embodiment of the present invention, the thickness of the functional layer in the second region of the first electrode is smaller than the height of the insulating layer, so that leakage current to adjacent elements is reduced. At the same time, the thickness of the functional layer in the inclined portion of the insulating layer is 20 nm or more, so that leakage current between the first electrode and the second electrode is reduced.

5(a) is an enlarged view of the dotted line portion B in FIG. 1. FIG. 5(a) shows the second region 21 of the first electrode and the inclined portion 31 of the insulating layer. The inclined portion 31 of the insulating layer is an inclined portion on the first region of the first electrode. The inclined portion 31 can also be called an inclined portion in contact with the light-emitting region or an inclined portion forming the inner periphery of the opening. In addition, in a plan view perpendicular to the substrate, the inclined portion and the first region of the first electrode overlap. In contrast, the inclined portion 32 is an inclined portion disposed between the first electrode and another first electrode in a plan view perpendicular to the substrate. It can also be called an inclined portion forming the outer periphery of the opening or an inclined portion between pixels. The height F of the upper surface of the organic layer in the second region 21 represents the height of the upper surface of the organic layer formed approximately parallel to the second region 21. The organic layer on the second region can also be called a flat portion of the organic layer on the first electrode.

The upper end 33 of the inclined portion 31 of the insulating layer is the position where the angle of the insulating layer is 0°, and the height of the upper end 33 of the inclined portion 31 is represented as E. The inclination angle θ of the inclined portion of the insulating layer may be constant at each position of the inclined portion as shown in FIG. 5(a), or the inclination angle may change depending on the position of the inclined portion. Even if the inclination angle changes, it is considered to be the same inclined portion when the inclination angle is greater than 0°, and the positions of both ends where the inclination angle is 0° are the upper end 33 and lower end 34 of the inclined portion 31. In the planar structure shown in FIG. 2, the inclined portion 31 is formed by going around each side of the hexagon.

The height F of the upper surface of the organic layer 4 is lower than the height E of the upper end 33 of the inclined portion 31. This is because the organic layer thickness of the organic light-emitting device according to this embodiment is smaller than the height of the insulating layer. That is, as shown in FIG. 5(a), the organic light-emitting device according to this embodiment has an organic layer along the inclined portion of the insulating layer. A region 41 (within the dotted line) of the organic layer is formed along the inclined portion 31. The organic layer along the inclined portion is a region formed approximately parallel to the inclined portion, and is separated by a perpendicular line to the insulating layer, like the organic layer region 41. In the planar structure shown in FIG. 2, the organic layer region 41 along the inclined portion 31 is a region that spans each side of the hexagon. Note that approximately parallel refers to a case where the inclination angle at a position of the inclined portion is the same as the inclination angle at the position where the perpendicular line to the inclined portion drawn from that position intersects with the upper surface of the organic layer 4, and the difference in the inclination angle is within the range of ±15°.

The region 42 of the organic layer in FIG. 5(a) is not the organic layer along the sloped portion 31 of the insulating layer. This is because the organic layer formed on the second region 21 is so thick that it buries the organic layer formed along the sloped portion 31.

Figure 5(b) shows, as a comparative example, an example in which the height E of the upper surface of the organic layer 4 is higher than the height F of the upper end 61 of the inclined portion 31. In this case, there is no organic layer along the inclined portion 31. This is because the organic layer formed on the second region 21 is so thick that it buries the organic layer formed along the inclined portion 31. In the example of Figure 5(b), the resistance of the organic layer is relatively low, so there are cases in which the reduction in leakage current to adjacent light-emitting elements is insufficient.

The inventors have found, while examining organic devices under various conditions, that if the layer thickness G of the organic layer in the inclined portion 31 shown in FIG. 5(a) is 20 nm or more, the leakage current between the upper electrode 5 and the lower electrode 2 can be significantly reduced. The layer thickness of the organic layer in the inclined portion is the layer thickness in the direction perpendicular to the inclined portion of the insulating layer. On the other hand, the layer thickness of the organic layer along the inclined portion is smaller than the layer thickness of the organic layer formed on the flat portion, and therefore the electrical resistance is high. In addition to the organic layer in the second region having a small layer thickness, the resistance of the organic layer is increased by the inclined portion, so that the leakage current to the adjacent light-emitting element is reduced. If the leakage current to the adjacent light-emitting element is reduced, it is possible to reduce unintended light emission of the light-emitting element and reduce the narrowing of the color gamut of the light-emitting device. The layer thickness G of the organic layer in the inclined portion 31 is preferably 25 nm or more, and particularly preferably 33 nm or more. This makes it possible to further reduce the leakage current between the upper electrode and the lower electrode.

Therefore, by using the organic device shown in FIG. 5(a), it is possible to reduce both the leakage current to adjacent light-emitting elements and the leakage current between the upper electrode and the lower electrode. The thickness of the organic layer in the direction perpendicular to the inclined portion may be 20 nm or more even at the thinnest part of one of the inclined portions. The thickness of the organic layer in the direction perpendicular to the inclined portion can be controlled by the inclination angle of the inclined portion, the deposition conditions of the organic layer, etc. The inclination angle of the inclined portion of the insulating layer may be 50° or less.

The organic light-emitting device according to this embodiment has multiple insulating layers. Although one of the insulating layers has been given as an example above, in the multiple insulating layers, the organic layer in the inclined portion may have a layer thickness of 20 nm or more in the direction perpendicular to the inclined portion.

The above describes the thickness of the organic layer in the inclined portion 31 of the insulating layer. On the other hand, for the inclined portion 32 of the insulating layer, it is preferable that the thickness of the organic layer in the direction perpendicular to the inclined portion is 20 nm or more. Although it is preferable that the thickness of the organic layer is 20 nm or more in both inclined portions, it is more preferable that the thickness is 20 nm or more in the inclined portion 31 than that the thickness is 20 nm or more in the inclined portion 32. This is because the organic layer in the inclined portion 31 contributes more to the leakage current between the first electrode and the second electrode than the organic layer in the inclined portion 32.

In addition, in the inclined portion on the first region of the first electrode of the multiple insulating layers, the layer thickness of the organic layer in the direction perpendicular to the inclined portion may be 20 nm or more. In the inclined portions of all the insulating layers, the layer thickness of the organic layer in the direction perpendicular to the inclined portion may be 20 nm or more. Furthermore, in the inclined portion disposed between the first electrode of the multiple insulating layers and another first electrode, the layer thickness of the organic layer in the direction perpendicular to the inclined portion may be 20 nm or more. Furthermore, in the inclined portion disposed between the first electrode of all the insulating layers and another first electrode, the layer thickness of the organic layer in the direction perpendicular to the inclined portion may be 20 nm or more.

In the organic light-emitting device according to this embodiment, the inclined surface of the inclined portion is not parallel to the upper surface of the first electrode, and the inclined surface of the inclined portion is a portion of the surface of the insulating layer between the upper surface of the insulating layer and the upper surface of the first electrode that the insulating layer covers. In other words, the inclined surface of the inclined portion is a portion of the surface of the insulating layer between an edge of the upper surface of the insulating layer and the upper surface of the first electrode. The angle of the inclined portion on the first electrode may be less than 90°. When the angle is less than 90°, the width of the opening formed by the insulating layer increases from the upper surface of the first electrode upward.

Second Embodiment
6 is a diagram of a second embodiment of the present invention. This is the same as the first embodiment except that the shape of the insulating layer 3 is different and a charge transport region is included in the lower part of the organic layer. The differences from the first embodiment and their effects will be described below.

The inclined portion 31 of the insulating layer on the first region of the first electrode includes a gently sloping portion (thick line portion) 311 and a steeply sloping portion (thick line portion) 312. The gently sloping portion is located between the upper end of the inclined portion and the lower end of the inclined portion. If the insulating layer has an upper surface, the height of the upper surface is the height of the upper end, and the upper surface itself is not included in the upper end. The steeply sloping portion is located between the gently sloping portion and the lower end of the inclined portion. More specifically, it is located between the lower end of the gently sloping portion and the lower end of the inclined portion.

In FIG. 6, the gently sloping portion 311 is a portion of the sloping portion 31 that contacts the region 41 of the organic layer along the sloping portion. The gently sloping portion is formed at an angle of θ1 with respect to the upper surface of the first electrode. If the upper surface of the first electrode is parallel to the horizontal plane, the angle of the gently sloping portion may be θ1 from the horizontal plane. The steeply sloping portion is disposed between the gently sloping portion and the lower end of the insulating layer, and is formed at an angle of θ2 with respect to the upper surface of the first electrode. The steeply sloping portion 312 is a portion of the sloping portion 31 that has an angle of θ2 larger than the portion of the gently sloping portion 311 that has the largest angle of θ1.

The inclination angle θ2 of the steeply inclined portion is greater than 50°, and the inclination angle θ1 of the gently inclined portion is less than or equal to 50°. Preferably, the inclination angle θ2 of the steeply inclined portion is greater than 50° and less than or equal to 90°, and the inclination angle θ1 of the gently inclined portion is greater than or equal to 30° and less than or equal to 50°.

The organic layer 4 is composed of a region 44 including a charge transport layer 43 and a light-emitting layer, and the charge transport layer is disposed on the first electrode side. The charge transport layer may have a different component from the organic layer. The height I of the upper surface 431 of the charge transport layer in the second region 21 of the first electrode is lower than the height H of the upper end of the steeply inclined portion 312. As a result, the charge transport layer 43 forms a region with a small layer thickness in a direction perpendicular to the steeply inclined portion, and a region along the steeply inclined portion 312.

When formed by vapor deposition, the thickness of the layer along the inclined portion becomes thinner as the inclination angle increases, making it easier to increase the resistance of the charge transport layer. The charge transport layer is an area of the organic layer with excellent charge transport capabilities, so it is likely to contribute to leakage current between light-emitting elements. However, if the resistance can be increased as described above, the leakage current between light-emitting elements can be reduced.

Therefore, the height F of the upper surface of the organic layer in the second region 21 of the first electrode is higher than the height H of the upper end of the steeply inclined portion 312. This is because a region of high resistance is formed in the organic layer 4 on the second region 21 due to the formation of the steeply inclined portion.

Even if the organic layer is thinned by an insulating layer having a sloped portion, in the organic light-emitting device according to this embodiment, the organic layer in the sloped portion has a layer thickness of 20 nm or more in the direction perpendicular to the sloped portion, so that leakage current between the first electrode and the second electrode is reduced.

In this embodiment, the gentle slope portion and the steep slope portion can be formed, for example, by using isotropic etching for the gentle slope portion 311 and anisotropic etching for the steep slope portion 312.

So far, we have given examples in which the inclined portion 31 of the insulating layer has a gentle slope portion and a steep slope portion, but the inclined portion 32 of the insulating layer may also have a gentle slope portion and a steep slope portion.

The inclination angles of the steep and gentle slope portions of the insulating layer may be constant along each slope as shown in FIG. 6, or the inclination angle may vary along the slope. In this case, the boundary between the gentle slope portion and the steep slope portion is the point where the inclination angle exceeds 50°.

The charge transport layer in this embodiment may be a hole transport layer. Generally, the charge mobility of the hole transport layer is higher than that of the electron transport layer, so that the structure of this embodiment can increase the resistance of the hole transport layer, thereby making it possible to increase the effect of reducing the leakage current between the light-emitting elements. In addition, the hole transport layer may be a hole transport region made of multiple organic compound layers.

When reducing leakage current between light-emitting elements, it is preferable that the light-emitting layer is of the electron trap type. An electron trap type is a light-emitting layer in which the energy of the lowest unoccupied molecular orbital of the dopant material contained in the light-emitting layer is 0.15 eV or more deeper than the energy of the lowest unoccupied molecular orbital of the host material that constitutes the main component of the light-emitting layer. This reduces the electron mobility of the light-emitting layer. Therefore, the leakage current between light-emitting elements due to holes can be reduced by increasing the resistance of the inclined portion, and the leakage current between light-emitting elements due to electrons can be reduced by increasing the resistance of the light-emitting layer, making it easy to reduce both the leakage current between light-emitting elements due to holes and electrons.

To obtain knowledge about the preferred inclination angle of the inclined portion in this embodiment, a film formation simulation using a deposition method was performed. Figure 7 is a diagram showing the layout of each component during the deposition simulation. The positions of the deposition source 201, the substrate 202, and the organic device 203 arranged on the substrate were set as shown in Figure 7, with R = 200 mm, r = 95 mm, and h = 340 mm.

The deposition distribution represented by the following formula (9) was set to n=2.
φ=φ ₀ cos ⁿ α (9)
Here, α is an angle, φ is the vapor flow density at angle α, and φ ₀ is the vapor flow density at α = 0. It is also assumed that the substrate 202 rotates around its center.

Assuming that there is an inclined portion with an inclination angle of 0° to 90° at the position of the organic device 203 on the substrate, and assuming that the layer thickness of the organic layer at an inclination angle of 0° is 76 nm, the layer thickness of the organic layer region along the inclined portion at each inclination angle was calculated.

Figure 8 shows the results of the film formation simulation. It can be seen that when the inclination angle is greater than 50°, the layer thickness of the organic layer region along the inclined portion tends to be thin, and when the inclination angle is 50° or less, the layer thickness of the organic layer region along the inclined portion tends to be thick. Therefore, in this embodiment, it is preferable that the inclination angle of the steep inclination portion is greater than 50°, and it is preferable that the inclination angle of the gentle inclination portion is 50° or less.

In this embodiment, the inclination angle of the steeply inclined portion may include a portion that is greater than 90°. This makes it easier for the layer thickness of the charge transport layer in the steeply inclined portion to be particularly thin, making it easier to reduce leakage current between light-emitting elements.

[Uses of the organic light-emitting element according to this embodiment]
The organic light-emitting device according to the present embodiment can be used as a component of a display device or a lighting device, and can also be used as an exposure light source for an electrophotographic image forming device, a backlight for a liquid crystal display device, a light-emitting device having a white light source and a color filter, etc.

The display device may be an image information processing device that has an image input unit that inputs image information from an area CCD, a linear CCD, a memory card, etc., has an information processing unit that processes the input information, and displays the input image on the display unit.

The display unit of the imaging device or inkjet printer may have a touch panel function. The driving method of this touch panel function is not particularly limited and may be an infrared method, a capacitance method, a resistive film method, or an electromagnetic induction method. The display device may also be used in the display unit of a multifunction printer.

Next, a display device according to this embodiment will be described. The display device may have an organic light-emitting element and a transistor connected to the organic light-emitting element. The transistor is an example of an active element.

The transistor may be connected to a first electrode constituting an organic light-emitting element through a contact hole provided in the interlayer insulating layer.

The method of electrical connection between the electrodes (anode, cathode) included in the organic light-emitting element and the electrodes (source electrode, drain electrode) included in the transistor is not particularly limited. In other words, it is sufficient that either the anode or the cathode is electrically connected to either the source electrode or the drain electrode of the transistor.

The transistors used in the display device are not limited to transistors using single crystal silicon wafers, but may be thin film transistors having an active layer on the insulating surface of a substrate. Examples of active layers include single crystal silicon, amorphous silicon, non-single crystal silicon such as microcrystalline silicon, and non-single crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. Thin film transistors are also called TFTs.

The transistors included in the display device may be formed within a substrate such as a Si substrate. Formed within a substrate here means that the substrate itself, such as a Si substrate, is processed to create the transistors. In other words, having a transistor within a substrate can be seen as the substrate and the transistor being formed integrally.

The organic light-emitting element according to this embodiment has its emission brightness controlled by a TFT, which is an example of a switching element, and by providing organic light-emitting elements on multiple surfaces, an image can be displayed with the emission brightness of each element. Whether to provide a transistor in the substrate or to use a TFT is selected according to the size of the display unit. For example, if the size is about 0.5 inches, it is preferable to provide the organic light-emitting element on a Si substrate.

Figure 9 is a schematic diagram showing an example of a display device according to this embodiment. The display device 1000 may have a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. Flexible printed circuits FPCs 1002 and 1004 are connected to the touch panel 1003 and the display panel 1005. Transistors are printed on the circuit board 1007. The battery 1008 may not be provided if the display device is not a portable device, and may be provided in a different position even if the display device is a portable device.

The display device according to this embodiment may be used in the display section of an imaging device having an optical section with multiple lenses and an imaging element that receives light that has passed through the optical section. The imaging device may have a display section that displays information acquired by the imaging element. The display section may be a display section exposed to the outside of the imaging device, or a display section that is disposed within the viewfinder. The imaging device may be a digital camera or a digital video camera.

FIG. 10(a) is a schematic diagram showing an example of an imaging device according to this embodiment. The imaging device 1100 may have a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 may have a display device according to this embodiment. In this case, the display device may display not only the image to be captured, but also environmental information, imaging instructions, etc. The environmental information may include the intensity of external light, the direction of external light, the speed at which the subject moves, the possibility that the subject will be blocked by an obstruction, etc.

The optimal timing for capturing an image is very short, so it is better to display the information as soon as possible. Therefore, it is preferable to use a display device that uses an organic light-emitting device according to one embodiment of the present invention. This is because organic light-emitting elements have a fast response speed. A display device that uses organic light-emitting elements can be used more preferably than liquid crystal display devices, which require high display speed.

The imaging device 1100 has an optical section (not shown). The optical section has multiple lenses, and forms an image on an imaging element housed in a housing 1104. The focus of the multiple lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically.

The display device according to this embodiment may have a color filter having red, green, and blue colors. The color filters may be arranged such that the red, green, and blue colors are arranged in a delta arrangement.

The display device according to this embodiment may be used in the display section of a mobile terminal. In this case, it may have both a display function and an operation function. Examples of the mobile terminal include mobile phones such as smartphones, tablets, and head-mounted displays.

Figure 10 (b) is a schematic diagram showing an example of an electronic device according to this embodiment. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may have a circuit, a printed circuit board having the circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel type reaction unit. The operation unit may be a biometric recognition unit that recognizes a fingerprint to perform operations such as unlocking. An electronic device having a communication unit may also be called a communication device.

Figure 11 is a schematic diagram showing an example of a display device according to this embodiment. Figure 11(a) shows a display device such as a television monitor or a PC monitor. The display device 1300 has a frame 1301 and a display unit 1302. The light-emitting device according to this embodiment may be used for the display unit 1302.

It has a frame 1301 and a base 1303 that supports a display unit 1302. The base 1303 is not limited to the form shown in FIG. 11(a). The bottom side of the frame 1301 may also serve as the base.

Furthermore, the frame 1301 and the display unit 1302 may be curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

Figure 11 (b) is a schematic diagram showing another example of the display device according to this embodiment. The display device 1310 in Figure 11 (b) is configured to be bendable, and is a so-called foldable display device. The display device 1310 has a first display unit 1311, a second display unit 1312, a housing 1313, and a bending point 1314. The first display unit 1311 and the second display unit 1312 may have a light-emitting device according to this embodiment. The first display unit 1311 and the second display unit 1312 may be a single display unit without a joint. The first display unit 1311 and the second display unit 1312 can be separated by the bending point. The first display unit 1311 and the second display unit 1312 may each display different images, or the first and second display units may display a single image.

Figure 12 (a) is a schematic diagram showing an example of a lighting device according to this embodiment. The lighting device 1400 may have a housing 1401, a light source 1402, a circuit board 1403, an optical film 1404, and a light diffusion section 1405. The light source may have an organic light-emitting element according to this embodiment. The optical filter may be a filter that improves the color rendering of the light source. The light diffusion section can effectively diffuse the light of the light source, such as for lighting up, and deliver the light over a wide range. The optical filter and the light diffusion section may be provided on the light emission side of the lighting. If necessary, a cover may be provided on the outermost part.

The lighting device is, for example, a device that illuminates a room. The lighting device may emit white light, daylight white light, or any other color from blue to red. It may have a dimming circuit that adjusts the light intensity. The lighting device may have an organic light-emitting element of the present invention and a power supply circuit connected thereto. The power supply circuit is a circuit that converts AC voltage into DC voltage. Furthermore, white has a color temperature of 4200K, and daylight white has a color temperature of 5000K. The lighting device may have a color filter.

The lighting device according to this embodiment may also have a heat dissipation section. The heat dissipation section dissipates heat from within the device to the outside, and examples of the heat dissipation section include metals with high specific heat, liquid silicon, etc.

Figure 12(b) is a schematic diagram of an automobile, which is an example of a moving body according to this embodiment. The automobile has tail lamps, which are an example of a lamp. The automobile 1500 has tail lamps 1501, and may be configured to turn on the tail lamps when braking or the like is performed.

The tail lamp 1501 may have an organic light-emitting element according to this embodiment. The tail lamp may have a protective member that protects the organic EL element. The protective member may be made of any material as long as it has a relatively high strength and is transparent, but it is preferable that the protective member is made of polycarbonate or the like. Polycarbonate may be mixed with a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like.

The automobile 1500 may have a body 1503 and a window 1502 attached to it. The window may be a transparent display as long as it is not a window for checking the front and rear of the automobile. The transparent display may have an organic light-emitting element according to this embodiment. In this case, the constituent materials of the electrodes and the like of the organic light-emitting element are made of transparent materials.

The moving body according to this embodiment may be a ship, an aircraft, a drone, or the like. The moving body may have a body and a lamp provided on the body. The lamp may emit light to indicate the position of the body. The lamp has an organic light-emitting element according to this embodiment.

As explained above, by using a device using the organic light-emitting element according to this embodiment, it is possible to achieve a display with good image quality and stability even over long periods of time.

[Example 1]
Hereinafter, an example of the organic light-emitting device 100 of this embodiment will be described. First, a metal layer was formed on the substrate 1, and a desired region of the metal layer was etched using a mask pattern or the like to form the lower electrode 2. Next, an insulating layer 3 was formed so as to cover the end of the lower electrode 2. In this example, the insulating layer 3 was formed of silicon oxide, and the thickness of the insulating layer 3 in the direction perpendicular to the upper surface of the substrate 1 on the upper surface of the lower electrode 2 was set to 80 nm. After the insulating layer 3 was formed, an opening 12 was formed by etching a desired region of the insulating layer 3 using a mask pattern or the like. As shown in FIG. 6, the insulating layer 3 had a shape having a gentle slope and a steep slope. The gentle slope 311 had an inclination angle of 40°, and the steep slope 312 had an inclination angle of 80°. The height of the upper end of the steep slope 312 with respect to the second region (flat portion) 21 of the upper surface of the first electrode was set to 50 nm. The height of the inclined portion 31 with respect to the second region (flat portion) 21 of the first electrode was set to 80 nm. The inclination angle of the gentle inclination portion 321 included in the inclination portion 32 of the insulating layer 3 was 40°, and the inclination angle of the steep inclination portion 322 was 80°. The height of the inclination portion 32 with respect to the flat portion 22 between the first electrode and the other first electrode was 80 nm. In this embodiment, the pixels were arranged in a delta arrangement, with the distance between adjacent openings 12 being 1.4 μm, and the distance between adjacent lower electrodes 2 being 0.6 μm. As shown in FIG. 2, the pixels were arranged in a delta arrangement with each pixel having a hexagonal shape.

Next, organic layer 4 was formed. The organic layer had a hole injection layer, a hole transport layer, an electron blocking layer, a two-layer light-emitting layer, an electron transport layer, and an electron injection layer, in that order. First, a 7-nm film of the material shown in Compound 1 below was formed on substrate 1 as a hole injection layer.

Next, the material shown in Compound 2 below was deposited to a thickness of 5 nm as the hole transport layer, and Compound 3 below was deposited to a thickness of 10 nm as the electron blocking layer. The light-emitting layer 42 had a two-layer laminate structure. First, a light-emitting layer was formed as the first light-emitting layer, with Compound 4 below as the host material and Compound 5 below as the light-emitting dopant. The weight ratio of the light-emitting dopant was adjusted to 3%, and the thickness of the first light-emitting layer was 10 nm.

Next, a second light-emitting layer was formed in which the host material was the above-mentioned compound 4 and the light-emitting dopant was the following compound 6. The weight ratio of the light-emitting dopant was adjusted to 1%, and the thickness of the second light-emitting layer was set to 10 nm. After the formation of the two-layer light-emitting layer, a film of the following compound 7 was formed to a thickness of 34 nm as an electron transport layer, and further, a film of LiF was formed to a thickness of 0.5 nm as an electron injection layer.

After the organic layer 4 was formed, a 10 nm thick MgAg alloy with a 1:1 ratio of Mg to Ag was deposited as the upper electrode 5. After the upper electrode 5 was formed, a 1.5 μm thick SiN film was deposited as the sealing layer 6 using the CVD method. After the protective layer 6 was formed, a color filter 7 was formed.

The ratio of the distance between the openings of two adjacent first electrodes, 1.4 μm, to the layer thickness of the organic layer on the first electrode, 76 nm (total of each organic layer), was 18, which was less than 50. The layer thickness of the organic layer in the second region (flat portion) 21 of the first electrode was 76 nm, which was lower than the height of the upper end of the inclined portion 31, 80 nm. In addition, the layer thickness of the organic layer in the flat portion 22, 76 nm, was lower than the height of the upper end of the inclined portion 32, 80 nm. The organic film thickness of the organic layer region 41 along the inclined portion 31 and the organic layer region 42 along the inclined portion 32 was 36 nm to 45 nm, which was 20 nm or more. The minimum wavelength λ of the peak of the emission spectrum of the light-emitting layer was 460 nm, the optical path length L was 146 nm, and the phase difference shift φ was -π, so that the following formula (8) was satisfied. Formula (8) is derived from the above formula (5).
(λ/8)×(−(2φ/π)−1)<L<(λ/8)×(−(2φ/π)+1) (8)

The organic layer also has a hole transport region between the first electrode and the light-emitting layer, which is made up of a hole injection layer and a hole transport layer. The height of the top surface of the charge transport region in the flat portion 21, 12 nm, relative to the flat portion 21 is lower than the height of the top end of the steeply inclined portion, 50 nm, and the height of the top surface of the organic layer in the flat portion 21, 76 nm, relative to the flat portion 21, is higher than the height of the top end of the steeply inclined portion 312, 50 nm. Similarly, the height of the top surface of the charge transport region in the flat portion 22, 12 nm, relative to the flat portion 22 is lower than the height of the top end of the steeply inclined portion, 50 nm, and the height of the top surface of the organic layer in the flat portion 22, 76 nm, relative to the flat portion 22, is higher than the height of the top end of the steeply inclined portion 322, 50 nm.

Next, the characteristics of the organic light-emitting device 100 of Example 1 that was formed will be described. First, the measurement method of _Ileak / _Ioled , which is an index related to the leak current between light-emitting elements, will be described by taking the R pixel as an example. The R pixel is energized in a state where the adjacent G pixel and B pixel are shorted (potential = 0V, i.e., shorted). At this time, the current flowing from the first electrode of the R pixel to the second electrode of the R pixel is _Ioled , and the sum of the currents flowing from the first electrode of the R pixel to the second electrode of the G pixel or the B pixel is _Ileak . _Ileak was measured at a potential value where _Ioled is 0.1 nA/pixel. The ratio of _Ileak to _Ioled is _Ileak / _Ioled . If _Ileak / _Ioled is 0.20 or less, it was evaluated that the leak current was reduced.

Next, the leakage current between the upper electrode and the lower electrode will be explained. Since the emission threshold voltage of an organic light-emitting element is about 2V, in a light-emitting element in which leakage current does not occur between the upper electrode and the lower electrode, no current flows even when a voltage of 1.5V is applied between the upper electrode and the lower electrode. However, in a light-emitting element in which leakage current occurs between the upper electrode and the lower electrode, current flows when a voltage of 1.5V is applied between the upper electrode and the lower electrode. Therefore, the current value when a voltage of 1.5V is applied between the upper electrode and the lower electrode of the R pixel was measured. In other words, the current that flows when 1.5V is applied is leakage current. In a light-emitting element in which leakage current between the upper electrode and the lower electrode is reduced, no current flows even when 1.5V is applied.

Next, a voltage of 5 V was applied between the upper and lower electrodes of the R pixel, and the current value and brightness were measured.

As a result, I _leak /I _oled was 0.15, the current amount when a voltage of 1.5 V was applied was 1×10 ⁻⁶ nA/pixel, the current amount when a voltage of 5 V was applied was 16 nA/pixel, and the luminance was 250 cd/m ² , showing good device characteristics in terms of luminance.

[Comparative Example 1]
An organic light-emitting device was fabricated in the same manner as in Example 1, except that the height of steeply inclined portion 312 relative to flat portion 21 was 90 nm, the height of inclined portion 31 relative to flat portion 21 was 120 nm, and the height of steeply inclined portion 322 relative to flat portion 22 was 90 nm, and the height of inclined portion 32 relative to flat portion 22 was 120 nm. Region 41 of the organic layer along inclined portion 31 was formed not only in gentle inclined portion 311 but also in the region along steeply inclined portion 312, and the thickness of the organic layer in the region along the steeply inclined portion was 18 to 24 nm. The same was true for inclined portion 32.

As a result, the leak current between the upper electrode and the lower electrode was too large, and an accurate value of I _leak /I _oled could not be measured. Since I _leak was large and I _oled was small, I _leak /I _oled became a very large value and could not be measured. In addition, the current amount when a voltage of 1.5 V was applied was very large at 1×10 ⁻¹ nA/pixel. A phenomenon occurred in which the intensity of the light emission became smaller around the inner circumference of the opening. This is thought to be due to the fact that there was a region in which the potential difference between the upper electrode and the lower electrode became smaller due to the influence of the leak current between the upper electrode and the lower electrode.

This shows that if the layer thickness of the organic layer region along the slope has a portion that is less than 20 nm, the leakage current between the upper electrode and the lower electrode becomes large.

[Comparative Example 2]
An organic device was fabricated in the same manner as in Example 1, except that the height of steeply inclined portion 312 relative to flat portion 21 was 30 nm, the height of inclined portion 31 was 50 nm, and the height of steeply inclined portion 322 relative to flat portion 22 was 30 nm, and the height of inclined portion 32 was 50 nm.

As a result, I _leak /I _oled was 0.25, and the amount of current when a voltage of 1.5 V was applied was below the measurement limit (10 ⁻⁶ nA/pixel). As shown by _{the I leak} /I _oled of 0.25, the proportion of leakage current was large, and the leakage current between the light-emitting elements was very large.

This shows that when the height of the top surface of the organic layer in the flat portion is lower than the height of the top end of the inclined portion, crosstalk between light-emitting elements is likely to become large.

[Comparative Example 3]
An organic light-emitting device was fabricated in the same manner as in Example 1, except that the thickness of the electron transport layer was 140 nm.

As a result, _Ileak / _Ioled was 0.35, and the amount of current when a voltage of 1.5 V was applied was below the measurement limit ( ^10-6 nA/pixel). As indicated by _{the Ileak} / _Ioled of 0.35, the proportion of leakage current was large, and the leakage current between the light-emitting elements was very large. This shows that crosstalk between the light-emitting elements is likely to increase when the height of the top surface of the organic layer in the flat portion is lower than the height of the top end of the inclined portion.

In addition, the thickness of the electron transport layer was 140 nm, and the total thickness of the organic layers on the lower electrode was 182 nm, which were thicker than those in Example 1. Therefore, the following formula (8) was not satisfied, and the λ/4 interference condition was not met.
(λ/8)×(−(2φ/π)−1)<L<(λ/8)×(−(2φ/π)+1) (8)

As a result, the current amount when a voltage of 5 V was applied was 6 nA/pixel, and the brightness was 90 cd/ ^m2 , and both the current amount and the brightness were small. This is thought to be because the resistance increased due to the thickening of the organic layer on the lower electrode.

[Comparative Example 4]
An organic light-emitting device was fabricated in the same manner as in Comparative Example 1, except that the angle of steeply inclined portion 312 with respect to flat portion 21 was set to 76°, and the angle of steeply inclined portion 322 was set to 76°. The film thickness of the thinnest portion of the film thickness in the direction perpendicular to the inclined portions of the organic layer along inclined portions 31 and 32 (hereinafter referred to as the organic minimum film thickness) was 19 nm. In addition, the amount of current when a voltage of 1.5 V was applied was 3×10 ⁻⁴ nA/pixel.

[Example 2]
An organic light-emitting device was fabricated in the same manner as in Example 1, except that the height of steeply inclined portion 312 relative to flat portion 21 was 70 nm, and the height of steeply inclined portion 322 was 70 nm. The minimum organic film thickness was 20 nm. The current amount when a voltage of 1.5 V was applied was 3×10 ⁻⁵ nA/pixel.

[Example 3]
An organic light-emitting device was fabricated in the same manner as in Example 1, except that the height of steeply inclined portion 312 relative to flat portion 21 was 65 nm, and the height of steeply inclined portion 322 was 65 nm. The minimum organic film thickness was 25 nm. The current amount when a voltage of 1.5 V was applied was 7×10 ⁻⁶ nA/pixel.

[Example 4]
An organic light-emitting device was fabricated in the same manner as in Example 1, except that the height of steeply inclined portion 312 relative to flat portion 21 was 58 nm, and the height of steeply inclined portion 322 was 58 nm. The minimum organic film thickness was 29 nm. The current amount when a voltage of 1.5 V was applied was 4×10 ⁻⁶ nA/pixel.

Figure 13 shows the relationship between the thickness of the thinnest part of the organic layer in the direction perpendicular to the inclined portion of the inclined portion and the leakage current between the upper electrode and the lower electrode. It shows the relationship between the thickness of the thinnest part of the organic layer in the direction perpendicular to the inclined portion of the inclined portion along the inclined portion 31 and the inclined portion 32 (minimum organic thickness) and the leakage current between the upper electrode and the lower electrode in the organic light-emitting devices of Comparative Examples 1 and 4 and Examples 1, 2, 3, and 4.

From this, it can be seen that when the layer thickness of the organic layer region along the slope portion is less than 20 nm, the leakage current between the upper electrode and the lower electrode becomes large. Conversely, when the layer thickness of the organic layer region along the slope portion is 20 nm or more, the leakage current between the upper electrode and the lower electrode can maintain good characteristics of less than 1×10 ⁻⁴ nA/pixel. Furthermore, when the layer thickness of the organic layer region along the slope portion is 25 nm or more, it is even better at less than 1×10 ⁻⁵ nA/pixel.

[Comparative Example 4]
An organic light-emitting device was produced in the same manner as in Example 1, except that the insulating layer was shaped as shown in Fig. 5(a) and the inclination angle of inclined portion 31 was set to 67° and the inclination angle of inclined portion 32 was set to 40°. Since the shape of the pixel is hexagonal, inclined portion 31 is made up of regions 1 to 6 counterclockwise from the right side of the paper in Fig. 2 according to the sides of the hexagon.

A current of 1 nA/pixel was applied to 25 pixels of the organic light-emitting device according to this comparative example. As a result, the phenomenon occurred in which the luminous intensity at the inner periphery of the opening became smaller. The situation in which the luminous intensity at the inner periphery of the opening became smaller varied depending on each side of the hexagon. It was found that this was related to the layer thickness of the organic layer region along the slope. The results are shown in Table 1.

This shows that when the layer thickness of the organic layer region along the slope is 33 nm or more, the phenomenon of the emission intensity decreasing on the inner circumference of the opening does not occur, and the leakage current between the upper electrode and the lower electrode is reduced.

REFERENCE SIGNS LIST 1 Substrate 2 Reflective electrode 3 Insulating layer 4 Organic layer 5 Semi-transparent electrode 6 Protective layer 7 Color filter 8 Planarization layer 9 Transmitted light 10 Light-emitting element 100 Organic light-emitting device 1000 Display device 1001 Upper cover 1002 Flexible printed circuit 1003 Touch panel 1004 Flexible printed circuit 1005 Display panel 1006 Frame 1007 Circuit board 1008 Battery 1009 Lower cover 1100 Imaging device 1101 Viewfinder 1102 Rear display 1103 Operation unit 1104 Housing 1200 Electronic device 1201 Display unit 1202 Operation unit 1203 Housing 1300 Display device 1301 Frame 1302 Display unit 1303 Base 1310 Display device 1311 First display portion 1312 Second display portion 1313 Housing 1314 Bend point 1400 Illumination device 1401 Housing 1402 Light source 1403 Circuit board 1404 Optical film 1405 Light diffusion portion 1500 Automobile 1501 Tail lamp 1502 Window 1503 Vehicle body

Claims (22)

a plurality of first electrodes, a second electrode, a functional layer disposed between the first electrodes and the second electrodes and covering the plurality of first electrodes, and an insulating layer covering an edge of the first electrodes and having a sloped portion on the first electrodes;
the first electrode has a first region including the end of the first electrode and covered with the insulating layer, and a second region in contact with the functional layer;
the functional layer is disposed continuously so as to cover the second regions of two adjacent first electrodes among the plurality of first electrodes and the insulating layer covering each of the two first electrodes;
an electronic device in which a layer thickness of the functional layer in the second region is smaller than a height from a top surface of the first electrode to a top surface of the insulating layer,
In a cross section perpendicular to a main surface of the first electrode, the inclined portion of the insulating layer has a gently inclined portion disposed between an upper end of the inclined portion and a lower end of the inclined portion, and a steeply inclined portion disposed between the gently inclined portion and the lower end and having an inclination angle with respect to the first electrode larger than an inclination angle of the gently inclined portion,
the steeply inclined portion has an inclination angle with respect to an upper surface of the first region of the first electrode that is greater than 50°, and the gently inclined portion has an inclination angle with respect to the first electrode that is equal to or smaller than 50°;
An electronic device characterized in that the height of the upper surface of the functional layer in the second region of the first electrode is higher than the height of the upper end of the steeply inclined portion. The electronic device according to claim 1, characterized in that the functional layer in the gently sloping portion of the insulating layer has a layer thickness of 20 nm or more in a direction perpendicular to the sloping surface of the gently sloping portion. The electronic device according to claim 1 or 2, characterized in that, in a plan view from a direction perpendicular to the main surface of the first electrode, the inclined portion and the first region of the first electrode overlap. The electronic device according to claim 1, characterized in that the functional layer in the gently sloping portion of the insulating layer has a layer thickness of 33 nm or more in a direction perpendicular to the sloping surface of the gently sloping portion. the insulating layer is covered with the functional layer and has another inclined portion different from the inclined portion, the other inclined portion being disposed between the first electrode and the other first electrode in a plan view from a direction perpendicular to a main surface of the first electrode,
5. The electronic device according to claim 1, wherein the functional layer in the other inclined portion has a layer thickness of 20 nm or more in a direction perpendicular to the other inclined portion. the insulating layer is covered with the functional layer and has another inclined portion different from the inclined portion, the other inclined portion being disposed between the first electrode and the other first electrode in a plan view from a direction perpendicular to a main surface of the first electrode,
The electronic device according to claim 1 , wherein the functional layer in the other inclined portion has a layer thickness of 33 nm or more in a direction perpendicular to the other inclined portion. The electronic device according to any one of claims 1 to 6, characterized in that in the insulating layers, the thickness of the functional layer in the inclined portion in the direction perpendicular to the inclined portion is 20 nm or more. The electronic device according to claim 7, characterized in that the insulating layers are covered with the functional layer, have another inclined portion different from the inclined portion, and the thickness of the functional layer in the other inclined portion in a direction perpendicular to the inclined surface of the other inclined portion is 20 nm or more. The electronic device according to any one of claims 1 to 6, characterized in that in the insulating layers, the thickness of the functional layer in the inclined portion in the direction perpendicular to the inclined portion is 33 nm or more. The electronic device according to claim 9, characterized in that the insulating layers are covered with the functional layer, have another inclined portion different from the inclined portion, and the thickness of the functional layer in the other inclined portion in a direction perpendicular to the inclined surface of the other inclined portion is 33 nm or more. the inclined surface of the inclined portion is not parallel to the top surface of the first electrode,
11. The electronic device according to claim 2, 4, 8, or 10, characterized in that the inclined surface in the inclined portion is a portion of the surface of the insulating layer between an upper surface of the insulating layer and an upper surface of the first electrode covered by the insulating layer. The electronic device according to any one of claims 1 to 11, characterized in that the insulating layer includes a portion in which the steeply inclined portion has an inclination angle of greater than 90° with respect to the first electrode. The electronic device according to any one of claims 1 to 12, characterized in that the functional layer is an organic layer having a light-emitting layer. The electronic device according to any one of claims 1 to 13, characterized in that the functional layer has a charge transport layer in contact with the first electrode, and the height of the charge transport layer in the second region of the first electrode is lower than the height of the upper end of the steeply inclined portion. The electronic device of claim 14, wherein the charge transport layer is a hole transport layer. 14. The electronic device according to claim 13, wherein the first electrode is a reflective electrode, the second electrode is a light extraction electrode, and an optical distance L between the reflective electrode and the light extraction electrode satisfies formula (1).
(λ/8)×(−(2φ/π)−1)<L<(λ/8)×(−(2φ/π)+1) (1)
Here, λ is the wavelength of the maximum peak of the emission spectrum emitted by the light emitting layer, n is the refractive index of the functional layer, and φ is the phase shift in the reflective electrode. The electronic device according to any one of claims 1 to 12, characterized in that the functional layer is an organic layer having a photoelectric conversion layer. A display device having a plurality of pixels, at least one of which has an electronic device according to any one of claims 1 to 16 and a transistor connected to the electronic device. an optical unit having a plurality of lenses, an image sensor that receives light that has passed through the optical unit, and a display unit that displays an image captured by the image sensor;
A photoelectric conversion device, comprising: a display unit comprising the electronic device according to claim 1 . An electronic device comprising a display unit having the electronic device according to any one of claims 1 to 16, a housing in which the display unit is provided, and a communication unit provided in the housing and communicating with the outside. A lighting device comprising a light source having the electronic device according to any one of claims 1 to 16, and a light diffusion section or optical film that transmits the light emitted by the light source. A moving object comprising a lighting fixture having an electronic device according to any one of claims 1 to 16, and a body on which the lighting fixture is mounted.

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