JP2020136260A - Electronic device, display apparatus, photoelectric conversion apparatus, electronic appliance, lighting apparatus, and moving body - Google Patents

Abstract

To provide an electronic device in which a leak current between a plurality of first electrodes is reduced and a leak current between the first electrode and a second electrode is reduced.SOLUTION: An electronic device according to the present disclosure includes a plurality of first electrodes, a second electrode, a functional layer arranged between the first electrode and the second electrode, and an insulating layer having an inclined portion on the first electrode, wherein the functional layer is continuously arranged so as to cover two adjacent first electrodes from 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 on the first electrode is smaller than the height from an upper surface of the first electrode to an upper surface of the insulating layer. In the functional layer in the inclined portion of the insulating layer, the layer thickness in a direction perpendicular to an inclined surface of the inclined portion is 20 nm or more.SELECTED DRAWING: Figure 5

Description

The present invention relates to an electronic device, a display device, a photoelectric conversion device, an electronic device, a lighting device, and a moving body.

As an electronic device using an organic layer, an organic light emitting element and an organic photoelectric conversion element have been proposed. The organic light emitting element is an element having an upper electrode, a lower electrode, and an organic layer arranged between them, and emits light by exciting an organic compound contained in the organic layer. In recent years, electronic devices equipped with organic light emitting elements have attracted attention, and among them, display devices are widely used.

As a method for forming an organic layer of an organic light emitting device, a method for forming an organic layer having a different composition for each emission color and a method for forming an organic layer having the same composition regardless of the emission color are known. In the method of forming an organic layer having the same configuration regardless of the emission color, a continuous organic layer is typically formed over a plurality of light emitting elements. Further, even when forming an organic layer having a different configuration for each emission color, some organic layers may be provided by being connected to a plurality of light emitting elements.

However, in a configuration in which the organic layer is connected between the plurality of light emitting elements and the plurality of light emitting elements, current leakage is likely to occur between the adjacent light emitting elements through the organic layer. Leakage current between light emitting elements causes unintended light emission of the light emitting element. The unintended light emission of the light emitting element narrows the color gamut that expresses the expressive performance of the display device.

Further, in the photoelectric conversion element using the organic layer, continuous organic photoelectric conversion layers are arranged so as to cover the plurality of lower electrodes. Leakage currents can occur between the plurality of lower electrodes via the organic photoelectric conversion layer, resulting in noise.

Since the organic layer is thin, the leakage current between the lower electrodes can be reduced. However, when the organic layer is thin, a leak current is likely to occur between the upper electrode and the lower electrode. In Patent Document 1, in order to reduce a short circuit between the upper electrode and the lower electrode, the layer thickness of the organic layer in the peripheral portion of the pixel, which is close to the partition wall separating each pixel, is the organic layer in the central portion of the pixel. Discloses a display device that is larger than the layer thickness of.

JP-A-2007-73608

Patent Document 1 describes the relationship between the layer thickness of the organic layer in the central portion of the pixel and the layer thickness of the organic layer in the peripheral portion of the pixel, but the inclined portion in the inclined portion of the partition wall that separates the pixels On the other hand, there is no description about the layer thickness of the organic layer in the vertical direction. Only 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 periphery of the pixel is caused by the thickness of the organic layer in the direction perpendicular to the inclined portion in the inclined portion of the partition wall that separates the pixels. It is insufficient to reduce the leakage current between the upper electrode and the lower electrode.

The present invention has been made in view of the above problems, and an object of the present invention is to reduce a leakage current between a plurality of first electrodes in an electronic device having a plurality of first electrodes, and to reduce the leakage current between the first electrode and the first electrode. It is to provide an electronic device which reduced the leakage current between two electrodes.

Therefore, the electronic device according to the embodiment of the present invention is arranged between the plurality of first electrodes, the second electrode, and the first electrode and the second electrode, and covers the plurality of first electrodes. The functional layer includes an insulating layer that covers the end of the first electrode and has an inclined portion on the first electrode, and the first electrode includes the end of the first electrode. It has a first region covered with the insulating layer and a second region in contact with the functional layer, and the functional layer is the first of two adjacent first electrodes of the plurality of first electrodes. The two regions and the insulating layer covering the two first electrodes are continuously arranged so as to cover the two regions, and the layer thickness of the functional layer in the second region is the insulation from the upper surface of the first electrode. An electronic device that is smaller than the height to the top of the layer
The functional layer in the inclined portion of the insulating layer provides an electronic device characterized in that the layer thickness in the direction perpendicular to the inclined surface of the inclined portion is 20 nm or more.

According to the present invention, in an electronic device having a plurality of first electrodes, an electronic device in which the leakage current between the plurality of first electrodes is reduced and the leakage current between the first electrode and the second electrode is reduced. Can be provided.

It is sectional drawing which shows typically the structure of the organic device which concerns on 1st Embodiment of this invention. It is a top view which shows typically the structure of the organic device of FIG. It is a schematic diagram and the circuit diagram of the organic light emitting device which concerns on embodiment. It is a relationship diagram of 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. It is an enlarged view of the cross-sectional view which shows typically the structure of the organic light emitting device which concerns on 1st Embodiment of this invention. It is an enlarged view of the cross-sectional view which shows typically the structure of the organic light emitting device which concerns on 2nd Embodiment of this invention. It is a layout drawing of a member in a vapor deposition simulation. It is a figure of the vapor deposition simulation result. It is a schematic diagram which shows an example of the display device which concerns on this embodiment. (A) It is a schematic diagram which shows an example of the image pickup apparatus which concerns on this embodiment. (B) It is a schematic diagram which shows an example of the electronic device which concerns on this Embodiment. (A) It is a schematic diagram which shows an example of the display device which concerns on this Embodiment. (B) It is a schematic diagram which shows an example of the foldable display device. (A) It is a schematic diagram which shows an example of the lighting apparatus which concerns on this embodiment. (B) It is a schematic diagram which shows an example of the automobile which has the lighting equipment for a vehicle which concerns on this embodiment. This is the relationship between the film thickness of the thinnest portion of the film thickness in the direction perpendicular to the inclined portion of the organic layer in the inclined portion and the leakage current between the upper electrode and the lower electrode.

The electronic device according to the embodiment of the present invention is arranged between the plurality of first electrodes, the second electrode, and the first electrode and the second electrode, and covers the plurality of first electrodes. It has a functional layer and an insulating layer that covers the end of the first electrode and has an inclined portion on the first electrode, and the first electrode includes the end of the first electrode and the insulation. It has a first region covered with a layer and a second region in contact with the functional layer, and the functional layer is the second region of two adjacent first electrodes of the plurality of first electrodes. And the insulating layer that covers the two first electrodes, respectively, and the layer thickness of the functional layer in the second region is increased from the upper surface of the first electrode to the insulating layer. An electronic device smaller than the height to the upper surface, wherein the functional layer in the inclined portion of the insulating layer has a layer thickness of 20 nm or more in the direction perpendicular to the inclined surface of the inclined portion. It is a device.

The electronic device according to the embodiment of the present invention includes a first electrode, a second electrode, a functional layer arranged between the first electrode and the second electrode, and an insulating layer covering the end of the first electrode. It can be said that it has an element having.

As described above, in the electronic device in which the leakage current between the first electrodes is reduced in the plurality of first electrodes, the thickness of the functional layer at the inclined portion of the insulating layer is 20 nm or more, so that the first electrode and the first electrode The leakage current to and from the second electrode can be reduced.

The effect of reducing the leakage current due to the thickness of the functional layer is obtained when the layer thickness of the functional layer is smaller than the height of the insulating layer covering the ends of the plurality of first electrodes, that is, when the functional layer is thin. Highly effective. Further, the effect is high when the functional layers are continuously formed by a plurality of elements, that is, when the functional layers are connected and formed.

When the electronic device is an organic light emitting element, the luminous efficiency can be improved by reducing the thickness of the functional layer, that is, the organic layer. This is because the light absorbed by the organic layer can be reduced. The distance L between the pair of electrodes of the organic light emitting element preferably satisfies the following formula (1). Satisfying the following equation (1) in the organic light emitting element means strengthening the optical interference between the electrodes, and the organic light emitting element can further improve the luminous efficiency. The luminous efficiency here can also be called the extraction efficiency.
(Λ / 8) × (− (2φ / π) -1) <L <(λ / 8) × (− (2φ / π) +1) (1)
In the formula (1), λ is the wavelength of the maximum peak of the emission spectrum emitted by the emission layer contained in the organic layer. The maximum peak is the peak having the highest intensity among the peaks of the emission spectrum. The peak wavelength may be the smallest wavelength of the peaks included in the emission. φ is the phase shift at the electrode. The phase shift is a 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 a part of light and reflects a part of the light.

The element of the electronic device according to the embodiment of the present invention may be an organic light emitting element. When the element is an organic light emitting device, 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 which is covered with an insulating layer and includes an edge, and a second region which is not covered with an insulating layer and is in contact with a functional layer. The first region may surround the second region.

The layer thickness of the organic layer 4 in the second region of the first electrode of the organic light emitting device according to the embodiment of the present invention is preferably less than 100 nm. As a result, the brightness is easily increased, and the effect of reducing the leakage current between the first electrode and the second electrode according to the present invention is increased.

Hereinafter, specific embodiments of the electronic device according to the embodiment of the present invention will be described with reference to the accompanying drawings. In the following description and drawings, common reference numerals are given to common configurations across a plurality of drawings. Therefore, a plurality of drawings will be referred to each other to explain a common configuration, and a configuration with a common reference numeral 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 the 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 and A'in FIG. 2 corresponds to FIG. 1, and the three elements 10 constitute one pixel. In the present embodiment, an example of pixels having a delta array is shown, but the present invention is not limited to this, and may be a striped array or a square array.

The organic light emitting device 100 includes a substrate 1 and a plurality 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 among the plurality of light emitting elements 10 included in the organic light emitting device 100. “R” in 10R indicates an element that emits red light. Similarly, 10G and 10B indicate that they emit green and blue, respectively. In the present specification, when a specific light emitting element is indicated among a plurality of light emitting elements 10, a subscript is added after the reference number such as the light emitting element 10 "R", and in any case, the light emitting element is simply emitted. It is indicated as "10". The same applies to other components.

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

In the present specification, "upper" and "lower" refer to the upper and lower parts in FIG. Of the main surfaces of the substrate 1, the surface on which the lower electrode 2 and the like are arranged is called an "upper" surface. The "height" is an upward distance from the upper surface (first surface) of the substrate 1. A portion parallel to the upper surface (first surface) of the substrate 1 may be specified, and the "height" may be specified based on the specified reference.

In FIG. 1, reference numeral 1 is abbreviated as a substrate, but may be an insulator arranged between a drive circuit including a transistor connected to the first electrode. Examples of the insulating material include an interlayer insulating layer composed of an inorganic substance such as silicon oxide and silicon nitride, and an organic substance such as polyimide and polyacrylic. The first issue insulating layer is sometimes called a flattening layer for the purpose of reducing the unevenness of the surface forming the first electrode.

For the lower electrode 2, a metal material having a reflectance of 80% or more with respect to the emission wavelength of the organic layer 4 may be used. For example, a metal such as Al or Ag, or an alloy obtained by adding Si, Cu, Ni, Nd or the like to these metals can 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 organic layer 4 of the lower electrode 2 with respect to the emission wavelength is high, the lower electrode 2 may have a laminated structure including a barrier layer. As the material of the barrier layer, a metal such as Ti, W, Mo, Au or an alloy thereof may be used. The barrier layer may be a metal layer arranged on the upper surface of the lower electrode. The upper surface of the lower electrode 2R is the reflecting surface 12R. The reflective surface may reflect light emitted from the organic layer. Similarly for the other pixels, it has 12G and 12B.

The insulating layer 3 may cover the end of the lower electrode and be arranged between the lower electrode and the functional layer. The lower electrode may have a first region covered with an insulating layer and a second region not covered with an insulating layer but covered with an organic layer. It can be said that the second region is in contact with the organic layer. The second region is also called the opening. This is because the second region can be seen as a recess formed by the insulating layer in the top bird's-eye view. The second region is a light emitting region of each light emitting element 10. That is, the shape of the top view of the light emitting region 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 a role of separating the first electrodes of each light emitting element.

The insulating layer 3 may have an inclined portion on the upper portion thereof. The upper part can be said to be the side opposite to the substrate or the functional layer side.

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

The organic layer 4 is arranged 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 be said that one organic layer is shared by a plurality of light emitting elements. The organic layer 4 may be integrally formed on the entire surface of the display area for displaying the image of the organic light emitting device 100. The organic layer 4 may include a hole transport layer, a light emitting layer, and an electron transport layer. Appropriate materials can be selected for the organic layer 4 from the viewpoints of luminous efficiency, drive life, and optical interference. The hole transport layer may function as an electron block layer or a hole injection layer, or may have a laminated structure such as a hole injection layer, a hole transport layer, or an electron block layer. The light emitting layer may have a laminated structure of light emitting layers that emit light of different colors, or may be a mixed layer in which light emitting dopants that emit light of different colors are mixed.

Further, the electron transport layer may function as a hole block layer or an electron injection layer, or may have a laminated structure of an electron injection layer, an electron transport layer, or a hole block layer.

Further, among the upper electrode and the lower electrode, the region between the electrode serving as the anode and the light emitting layer is the hole transport region, and the region between the electrode serving as 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.

Further, the configuration may have a plurality of light emitting layers, and an intermediate layer may be provided between the plurality of light emitting layers. It may be an organic light emitting device having a tandem structure in which the intermediate layer is a charge generation layer. In the tandem configuration, 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 arranged on the organic layer 4. It is continuously formed on a plurality of elements and shared by a plurality of light emitting elements 10. Similar to the organic layer 4, the upper electrode 5 may be integrally formed on the entire surface of the display area for displaying the image of the organic light emitting device 100. The upper electrode 5 may be an electrode that transmits at least a part of the light that has reached the lower surface of the upper electrode 5. The upper electrode may function as a semi-transmissive reflective layer that transmits a part of light and reflects another part (that is, transflective). The upper electrode 5 can be formed of, for example, a metal such as magnesium or silver, an alloy containing magnesium or silver as a main component, or an alloy material containing an alkali metal or an alkaline earth metal. Further, an oxide conductor or the like may be used for the upper electrode 5. Further, the upper electrode 5 may have a laminated structure as long as it has an appropriate transmittance.

The protective layer 6 may be made of a material having low permeability of 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 by using, for example, a CVD method. On the other hand, it may be formed by using an aluminum oxide, silicon oxide and titanium oxide atomic layer deposition method (ALD method). The combination of the constituent material of the protective layer and the manufacturing method is not limited to the above examples, but may be manufactured in consideration of the layer thickness to be formed, the time required for the formation, and the like. The protective layer 6 may have a single-layer structure or a laminated structure as long as it transmits light transmitted through the upper electrode 5 and has sufficient moisture blocking performance.

The color filter 7 is formed on the protective layer 6. Like the color filter 7R and the color filter 7G shown in FIG. 1, they may be in contact with each other without a gap. Further, the color filter may be arranged so as to overlap the color filters of other colors. The color filter may have a flattening layer 8 between the color filter and the protective layer. Further, a flattening layer may be provided on the color filter. The flattening layer on the color filter may be made of the same material as the flattening layer under the color filter. As the material of these flattening layers, for example, an acrylic resin, an epoxy resin, or a polyimide resin may be used.

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 opening end. The shortest distance between.

In the electronic device according to the embodiment of the present invention, the ratio of the distance from the opening of the first electrode to the opening of the adjacent first electrode to the layer thickness of the organic layer on the first electrode is less than 50. It may be. The organic light emitting device in this numerical range is a device in which the light emitting elements are arranged in high definition so that the leakage current between the light emitting elements can be a problem. The rationale will be explained below.

FIG. 3 is a schematic view 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 FIG. 1 is that the insulating layer does not have an inclined portion and the leakage current between the elements is not reduced. The equivalent circuit of the light emitting element 10R is superimposed on the schematic diagram. It shows the resistance value of the organic layer of FIG. 3, and does not incorporate an electronic circuit. Further, an equivalent circuit of the light emitting element 10G is also described in order to explain the leakage current between the light emitting elements.

Assuming that the organic layer thickness on the lower electrode 2R is C, the distance between the lower electrode 2R and the opening of the lower electrode 2G is D, and the resistance per unit area in the thickness direction of the organic layer is r, the horizontal direction of the organic layer The resistance per unit area in is r (D / C). Here, the current flowing through the light emitting element 10R _{I R,} and the current flowing through the light emitting element 10G and _{I G,} the following relationship holds.
_{I G / I R = 1 /} (1 + D / C) (2)
That is, even if only the red light emitting element 10R is to emit light, a current flows through the green light emitting element 10G to emit light, which depends on the D / C.

When light is emitted in the same amount of current, the red light emitting device 10R only emission spectrum S _R, when the emission spectrum of only the green light emitting element 10G S _G, and the emission spectrum S in consideration of the leakage current between the light emitting element _{R + G} is represented by the following equation (3).
_{S R + G = S R +} S G (I G / I R) (3)
FIG. 4 shows a graph obtained by calculating the chromaticity coordinates of SR _{+ G in} the CIExy space and using the x value as the vertical axis and D / C as the horizontal axis. In FIG. 4, the change in the x-coordinate means that green is also emitted even though it is intended to emit red. That is, in FIG. 4, the 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 a leak current between the light emitting elements is likely to occur, the leak current between the light emitting elements may not be a problem when the D / C is 50 or more. On the other hand, when the D / C is less than 50, the x value is greatly reduced and the red color purity is significantly reduced. Therefore, the light emitting elements are arranged with high definition so that the leakage current between the light emitting elements can be a problem. It is an organic light emitting device. That is, when the D / C is less than 50, the effect of reducing the leakage current of the organic light emitting device according to the present embodiment is particularly high.

The optical distance between the pair of electrodes of the organic light emitting device according to the embodiment of the present invention may be a strong interference structure. The strong interference structure can also be called a resonance structure.

By forming each organic layer in the light emitting element so as to satisfy the conditions of the optical interference of the strengthening, the light extracted from the organic light emitting device can be strengthened by the optical interference. If the optical conditions are such that the light taken out in the front direction is strengthened, the light is emitted in the front direction with higher efficiency. Further, it is known that the half width of the emission spectrum of light enhanced 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 light emitting position of the light emitting layer to the reflecting surface of the light reflecting material is set to d ₀ = iλ / 4n ₀ (i = 1, 3, 5, ...). By adjusting it, it can be a strong interference.

As a result, the radiation distribution of light having a wavelength of λ has more components in the front direction, and the front brightness is improved. Note that n ₀ is the refractive index at the wavelength λ of the layer from the light emitting position to the reflecting surface.

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

The optical distance Ls from the light emitting position to the reflecting surface of the light extraction electrode is given by the following equation (5), where φs [rad] is the sum of the phase shifts when light of wavelength λ is reflected on the emitting surface. Shown. In the following equation (5), m'is an integer of 0 or more.
Ls = (2m'-(φs / π)) x (λ / 4) =-(φs / π) x (λ / 4) (5)

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

At this time, in the actual light emitting element, it is not necessary to exactly match the above equation in consideration of the viewing angle characteristics and the like, which have a trade-off relationship with the front extraction efficiency. Specifically, there may be an error within the range of ± λ / 8 from the value in which L satisfies the equation (6). The permissible value at which the value of L may deviate from the interference condition may be 50 nm or more and 75 nm or less.

Therefore, it is preferable that the organic light emitting device according to the present invention satisfies the following formula (7). More preferably, L may be within the range of ± λ / 16 from the value satisfying the formula (6), and it is preferable to satisfy the following formula (7').
(Λ / 8) × (4m− (2φ / π) -1) <L <(λ / 8) × (4m− (2φ / π) +1) (7)
(Λ / 16) x (8m- (4φ / π) -1) <L <(λ / 16) x (8m- (4φ / π) + 1) (7')
The light emitting device according to the present invention preferably has optical interference conditions of m = 0 and m'= 0, that is, λ / 4 in the formulas (7) and (7'). In that case, the equations (7) and (7') are expressed as the equations (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 the formulas (7) and (7'), when m = 0 and m'= 0, the film thickness of the organic layer is the thinnest among the strengthened interference structures. As a result, the drive voltage of the light emitting element becomes low, and higher brightness can be emitted within the upper limit of the power supply voltage. When the organic layer becomes thin, a leak current between the upper electrode and the lower electrode is likely to occur. Therefore, by satisfying the requirements of the present invention, the effect of reducing the leak current between the upper electrode and the lower electrode becomes particularly large.

Here, the emission wavelength λ may be the emission wavelength at which the emission intensity has the maximum peak. The emission of the organic compound may be the wavelength of the minimum peak because the maximum peak is generally the maximum emission in the emission spectrum.

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

That is, in the electronic device according to the embodiment of the present invention, the layer thickness of the functional layer in the second region of the first electrode is smaller than the height of the insulating layer, so that the leakage current to the adjacent element is reduced. To. At the same time, since the layer thickness of the functional layer at the inclined portion of the insulating layer is 20 nm or more, the leakage current between the first electrode and the second electrode is reduced.

FIG. 5A is an enlarged view of the dotted line portion B of FIG. FIG. 5A 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 referred to as an inclined portion in contact with the light emitting region and an inclined portion forming the inner circumference of the opening. Further, in a plan view from a direction perpendicular to the substrate, the inclined portion and the first region of the first electrode are overlapped with each other. On the other hand, the inclined portion 32 is an inclined portion arranged between the first electrode and the other first electrode in a plan view in a direction perpendicular to the substrate. It can also be called an inclined portion forming the outer circumference 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 substantially parallel to the second region 21. The organic layer on the second region can also be referred to as 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 a position where the angle of the insulating layer becomes 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. 5A, or the inclination angle may change depending on the position of the inclined portion. Even when the inclination angle changes, it is regarded as the same inclined portion in the range where the inclination angle is larger than 0 °, and the positions of both ends where the inclination angle becomes 0 ° are the upper end 33 and the lower end 34 of the inclined portion 31. In the planar structure shown in FIG. 2, the inclined portion 31 is formed so as to go 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 the present embodiment is smaller than the height of the insulating layer. That is, as shown in FIG. 5A, the organic light emitting device according to the present embodiment has an organic layer along the inclined portion of the insulating layer. A region 41 (inside 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 substantially parallel to the inclined portion, and is separated by a perpendicular line to the insulating layer like the region 41 of the organic layer. In the planar structure shown in FIG. 2, the region 41 of the organic layer along the inclined portion 31 is a region that goes around each side of the hexagon and straddles it. It should be noted that "generally parallel" means that the inclination angle at a position where the inclined portion is present and the inclination angle at the position where the perpendicular line drawn from that position intersects the upper surface of the organic layer 4 are the same. It refers to the case where the difference in angle is within the range of ± 15 °.

The region 42 of the organic layer in FIG. 5A is not an organic layer along the inclined portion 31 of the insulating layer. This is because the organic layer formed on the second region 21 has a large layer thickness, so that the organic layer formed along the inclined portion 31 is filled.

FIG. 5B 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 of the upper end 61 of the inclined portion 31 than F. 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 has a large layer thickness, so that the organic layer formed along the inclined portion 31 is filled. In the case of the example of FIG. 5B, since the resistance of the organic layer is relatively low, the reduction of the leakage current to the adjacent light emitting element may not be sufficient.

The present inventor has found that when the layer thickness G of the organic layer of 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. Et al. Found in examining organic devices under various conditions. 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, so that the electric resistance is high. In addition to the organic layer in the second region where the layer thickness is small, 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 the 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 of the inclined portion 31 is preferably 25 nm or more, and particularly preferably 33 nm or more. As a result, the leakage current between the upper electrode and the lower electrode can be further reduced.

Therefore, by using the organic device shown in FIG. 5A, both the leakage current to the adjacent light emitting element and the leakage current between the upper electrode and the lower electrode can be reduced. The layer thickness of the organic layer in the direction perpendicular to the inclined portion may be 20 nm or more even in the portion where the layer thickness of one inclined portion is the thinnest. The layer 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 film forming condition of the organic layer, and the like. The inclination angle of the inclined portion of the insulating layer may be 50 ° or less.

The organic light emitting device according to the present embodiment has a plurality of insulating layers. In the above, one of the insulating layers is taken as an example, but in the plurality of 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.

In the above, the layer thickness of the organic layer in the inclined portion 31 of the insulating layer has been described. On the other hand, also for the inclined portion 32 of the insulating layer, it is preferable that the layer thickness of the organic layer in the direction perpendicular to the inclined portion is 20 nm or more. It is preferable that the layer thickness of the organic layer is 20 nm or more in both inclined portions, but it is better that the inclined portion 31 satisfies the layer thickness of 20 nm or more in the inclined portion 32. It is preferable that the thickness is 20 nm or more. This is because the organic layer in the inclined portion 31 contributes to the leakage current between the first electrode and the second electrode more than the organic layer in the inclined portion 32.

Further, in the inclined portion on the first region of the first electrode of the plurality of 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 portion 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. Further, in the inclined portion arranged between the first electrode of the plurality of insulating layers and the other first electrodes, the layer thickness of the organic layer in the direction perpendicular to the inclined portion may be 20 nm or more. Further, in the inclined portion arranged between the first electrode and the other first electrodes 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.

In the organic light emitting device according to the present embodiment, the inclined surface in the inclined portion is not parallel to the upper surface of the first electrode, and the inclined surface in the inclined portion is the upper surface of the insulating layer and the insulating layer among the surfaces of the insulating layer. It is a part between the upper surface of the first electrode covered by. In other words, the inclined surface of the inclined portion is a portion of the surface of the insulating layer between the end 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 smaller than 90 °. When the angle is smaller than 90 °, the width of the opening by the insulating layer increases from the upper surface of the first electrode upward.

<Second embodiment>
FIG. 6 is a diagram of a second embodiment according to the present invention. It is the same as the first embodiment except that the shape of the insulating layer 3 is different and the charge transport region is included in the lower part of the organic layer. Hereinafter, the difference from the first embodiment and its effect will be described.

The inclined portion 31 of the insulating layer on the first region of the first electrode includes a gently inclined portion (thick line portion) 311 and a steeply inclined portion (thick line portion) 312. The gently inclined portion is arranged between the upper end of the inclined portion and the lower end of the inclined portion in the inclined portion. When 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 inclined portion is arranged between the gently inclined portion and the lower end of the inclined portion. More specifically, it is arranged between the lower end of the gently inclined portion and the lower end of the inclined portion.

In FIG. 6, the gently inclined portion 311 is a portion of the inclined portion 31 that is in contact with the region 41 of the organic layer along the inclined portion. The gently inclined 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 inclined portion may be θ1 from the horizontal plane. The steeply inclined portion is arranged between the gently inclined 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 inclined portion 312 is a portion of the inclined portion 31 having an inclination angle θ2 larger than the portion having the largest inclination angle θ1 among the gently inclined portions 311.

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

The organic layer 4 is composed of a charge transport layer 43 and a region 44 including a light emitting layer, and the charge transport layer is arranged on the first electrode side. The components of the organic layer of the charge transport layer may be different from those of 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 having a small layer thickness in the direction perpendicular to the steep slope portion and a region along the steep slope portion 312.

When formed by the thin-film deposition method, the thickness of the layer along the inclined portion becomes thinner as the inclination angle is large, so that the charge transport layer tends to have high resistance. Since the charge transport layer is a region having excellent charge transport capacity among the organic layers, it easily contributes to the leakage current between the light emitting elements. However, if the resistance can be increased as described above, the leak current between the light emitting elements can be reduced. be able to.

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 the organic layer 4 on the second region 21 forms a region with high resistance due to the formation of the steeply inclined portion.

Even when the organic layer is thinned by the insulating layer having the inclined portion, in the organic light emitting device according to the present embodiment, the organic layer in the inclined portion has a layer thickness in the direction perpendicular to the inclined portion. Since it is 20 nm or more, the leakage current between the first electrode and the second electrode is reduced.

As for the gently inclined portion and the steeply inclined portion according to the present embodiment, for example, the gently inclined portion 311 can be formed by using isotropic etching or the like, and the steeply inclined portion 312 is formed by using anisotropic etching or the like. be able to.

Up to this point, the example in which the inclined portion 31 of the insulating layer has a gently inclined portion and a steeply inclined portion has been given, but the inclined portion 32 of the insulating layer may have a gently inclined portion and a steeply inclined portion.

The inclination angles of the steeply inclined portion and the gently inclined portion of the insulating layer may be constant in the inclined portion as shown in FIG. 6, or the inclination angle may be changed along the inclined portion. In this case, the boundary between the gently inclined portion and the steeply inclined portion is a point where the inclination angle exceeds 50 °.

The charge transport layer in this embodiment may be a hole transport layer. In general, the hole transport layer has a higher charge mobility than the electron transport layer. Therefore, by adopting the structure of the present embodiment, the hole transport layer can be made highly resistant, and between light emitting elements. The effect of reducing the leakage current can be increased. Further, the hole transport layer may be a hole transport region composed of a plurality of compound layers.

When reducing the leakage current between the light emitting elements, the light emitting layer is preferably an electron trap type. The electron trap type is a light emitting layer when the energy of the lowest unoccupied orbit of the dopant material contained in the light emitting layer is 0.15 eV or more deeper than the energy of the lowest unoccupied orbit of the host material which occupies the main component of the light emitting layer. is there. As a result, the electron mobility of the light emitting layer is reduced. Therefore, the leak current between the light emitting elements due to holes can be dealt with by increasing the resistance due to the inclined portion, and the leak current between the light emitting elements due to electrons can be dealt with by increasing the resistance due to the light emitting layer. It is easy to reduce both leakage currents between them.

In order to obtain knowledge about the preferred inclination angle of the inclined portion in the present embodiment, a film formation simulation by a vapor deposition method was carried out. FIG. 7 is a layout diagram of each member during the vapor deposition simulation. The positions of the vapor deposition source 201, the substrate 202, and the organic device 203 arranged on the substrate were set as shown in FIG. 7, and R = 200 mm, r = 95 mm, and h = 340 mm.

The vapor deposition distribution n = 2 represented by the following equation (9).
φ = φ ₀ cos ⁿ α (9)
Here, α is an angle, φ is a steam flow density at an angle α, and φ ₀ is a steam flow density at α = 0. Further, it is assumed that the substrate 202 rotates at the center of the substrate.

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, the inclined portion at each inclination angle when the layer thickness of the organic layer at the inclination angle of 0 ° is 76 nm. The layer thickness of the region of the organic layer along was calculated.

FIG. 8 shows the result of the film formation simulation. From this, when the inclination angle is larger 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 of the organic layer region along the inclined portion is formed. It can be seen that the thickness tends to increase. Therefore, the inclination angle of the steeply inclined portion of the present embodiment is preferably larger than 50 °, and the inclined angle of the gently inclined portion is preferably 50 ° or less.

The inclination angle of the steeply inclined portion according to the present embodiment may include a portion larger than 90 °. As a result, the thickness of the charge transport layer in the steeply inclined portion tends to be particularly thin, and the leakage current between the light emitting elements tends to be reduced.

[Use of organic light emitting device according to this embodiment]
The organic light emitting element according to the present embodiment can be used as a constituent member of a display device or a lighting device. In addition, there are applications such as an exposure light source of an electrophotographic image forming apparatus, a backlight of a liquid crystal display device, and a light emitting device having a color filter as a white light source.

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

Further, the display unit of the image pickup device or the inkjet printer may have a touch panel function. The drive method of this touch panel function may be an infrared method, a capacitance method, a resistance film method, or an electromagnetic induction method, and is not particularly limited. Further, the display device may be used as a display unit of a multifunction printer.

Next, the 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. Transistors are an example of active devices.

The transistor may be connected to the first electrode constituting the 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. That is, it is sufficient that either the anode or the cathode and either the source electrode or the drain electrode of the transistor are electrically connected.

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

The transistor included in the display device may be formed in a substrate such as a Si substrate. Here, being formed in the substrate means that a transistor is manufactured by processing the substrate itself such as a Si substrate. That is, having a transistor in the substrate can also be seen as the substrate and the transistor being integrally formed.

In the organic light emitting element according to the present embodiment, the emission brightness is controlled by a TFT which is an example of a switching element, and by providing the organic light emitting element in a plurality of planes, an image can be displayed by each emission brightness. Whether to provide a transistor in the substrate or to use a TFT is selected depending on the size of the display unit. For example, if the size is about 0.5 inch, it is preferable to provide an organic light emitting element on the Si substrate. ..

FIG. 9 is a schematic view showing an example of the display device according to the present 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 the upper cover 1001 and the lower cover 1009. Flexible print circuits FPC1002 and 1004 are connected to the touch panel 1003 and the display panel 1005. A transistor is printed on the circuit board 1007. The battery 1008 may not be provided if the display device is not a portable device, or may be provided at a different position even if it is a portable device.

The display device according to the present embodiment may be used as a display unit of an image pickup device having an optical unit having a plurality of lenses and an image pickup element that receives light that has passed through the optical unit. The image pickup device may have a display unit that displays information acquired by the image pickup device. Further, the display unit may be a display unit exposed to the outside of the image pickup apparatus or a display unit arranged in the finder. The image pickup device may be a digital camera or a digital video camera.

FIG. 10A is a schematic view showing an example of the image pickup apparatus according to the present embodiment. The image pickup apparatus 1100 may include 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 the present embodiment. In that case, the display device may display not only the image to be captured but also environmental information, imaging instructions, and the like. The environmental information may include the intensity of the outside light, the direction of the outside light, the moving speed of the subject, the possibility that the subject is shielded by a shield, and the like.

Since the optimum timing for imaging is a short time, it is better to display the information as soon as possible. Therefore, it is preferable to use a display device using the organic light emitting device according to the embodiment of the present invention. This is because the organic light emitting element has a high response speed. A display device using an organic light emitting element can be more preferably used than these devices and liquid crystal display devices, which require a display speed.

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

The display device according to the present embodiment may have a color filter having red, green, and blue. In the color filter, the red, green, and blue may be arranged in a delta arrangement.

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

FIG. 10B is a schematic diagram showing an example of the electronic device according to the present embodiment. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may include 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 and releases the lock. An electronic device having a communication unit can also be called a communication device.

FIG. 11 is a schematic view showing an example of the display device according to the present embodiment. FIG. 11A is 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 the present embodiment may be used for the display unit 1302.

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

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

FIG. 11B is a schematic view showing another example of the display device according to the present embodiment. The display device 1310 of FIG. 11B is a foldable display device, which 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 the present embodiment. The first display unit 1311 and the second display unit 1312 may be a single display device having no joints. The first display unit 1311 and the second display unit 1312 can be separated by a bending point. The first display unit 1311 and the second display unit 1312 may display different images, or the first and second display units may display one image.

FIG. 12A is a schematic view showing an example of the lighting device according to the present embodiment. The lighting device 1400 may include a housing 1401, a light source 1402, a circuit board 1403, an optical film 1404, and a light diffusing unit 1405. The light source may have the organic light emitting element according to the present embodiment. The optical filter may be a filter that improves the color rendering property of the light source. The light diffusing unit can effectively diffuse the light of the light source such as lighting up and deliver the light to a wide range. The optical filter and the light diffusing unit may be provided on the light emitting side of the illumination. If necessary, a cover may be provided on the outermost side.

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

Further, the lighting device according to the present embodiment may have a heat radiating unit. The heat radiating unit releases the heat inside the device to the outside of the device, and examples thereof include metals and liquid silicon having a high specific heat.

FIG. 12B is a schematic view of an automobile which is an example of a moving body according to the present embodiment. The vehicle has a tail lamp, which is an example of a lamp. The automobile 1500 may have a tail lamp 1501 and may be in a form in which the tail lamp is turned on when a brake operation or the like is performed.

The tail lamp 1501 may have the organic light emitting element according to the present embodiment. The tail lamp may have a protective member that protects the organic EL element. The protective member has a certain degree of high strength and may be made of any material as long as it is transparent, but it is preferably made of polycarbonate or the like. A flange carboxylic acid derivative, an acrylonitrile derivative, or the like may be mixed with the polycarbonate.

The automobile 1500 may have a vehicle body 1503 and a window 1502 attached to the vehicle body 1503. The window may be a transparent display as long as it is not a window for checking the front and rear of the vehicle. The transparent display may have the organic light emitting device according to the present embodiment. In this case, the constituent material such as the electrode of the organic light emitting element is composed of a transparent member.

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

As described above, by using the apparatus using the organic light emitting element according to the present embodiment, it is possible to perform stable display even for a long time display with good image quality.

[Example 1]
Hereinafter, examples of the organic light emitting device 100 of the present 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, the insulating layer 3 was formed so as to cover the end of the lower electrode 2. In this embodiment, the insulating layer 3 is formed of silicon oxide, and the thickness of the insulating layer 3 on the upper surface of the lower electrode 2 in the direction orthogonal to the upper surface of the substrate 1 is 80 nm. After forming the insulating layer 3, the 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 shape of the insulating layer 3 is a shape having a gently inclined portion and a steeply inclined portion. The inclination angle of the gently inclined portion 311 was 40 °, and the inclination angle of the steeply inclined portion 312 was 80 °. The height of the upper end of the steeply inclined portion 312 with respect to the second region (flat portion) 21 on the upper surface of the first electrode was set to 50 nm. Further, 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 gently inclined portion 321 included in the inclined portion 32 of the insulating layer 3 was 40 °, and the inclination angle of the steeply inclined portion 322 was 80 °. Further, the height of the inclined portion 32 with respect to the flat portion 22 between the first electrode and the other first electrode was set to 80 nm. In this embodiment, the pixel arrangement is a delta arrangement, the distance between the openings 12 adjacent to each other is 1.4 μm, and the distance between the lower electrodes 2 adjacent to each other is 0.6 μm. As shown in FIG. 2, the pixels have a delta arrangement in which each pixel has a hexagonal shape.

Next, the organic layer 4 was formed. The organic layer has a hole injection layer, a hole transport layer, an electron block layer, a two-layer light emitting layer, an electron transport layer, and an electron injection layer in this order. First, a 7 nm film was formed on the substrate 1 as a hole injection layer as shown in the following compound 1.

Next, as the hole transport layer, the material shown in the following compound 2 was formed at 5 nm, and as the electron block layer, the following compound 3 was formed at 10 nm. The light emitting layer 42 has a two-layer laminated structure. First, as the first light emitting layer, a light emitting layer was formed in which the host material was the following compound 4 and the light emitting dopant was the following compound 5. The weight ratio of the light emitting dopant was adjusted to 3%, and the layer thickness of the first light emitting layer was 10 nm.

Next, as the second light emitting layer, a light emitting layer was formed in which the host material was the above 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 layer thickness of the second light emitting layer was 10 nm. After forming the light emitting layer having a two-layer structure, the following compound 7 was formed into a film of 34 nm as an electron transport layer, and LiF was further formed into a film of 0.5 nm as an electron injection layer.

After the formation of the organic layer 4, an MgAg alloy having a ratio of Mg and Ag of 1: 1 was formed as an upper electrode 5 at 10 nm. After the formation of the upper electrode 5, 1.5 μm of SiN was formed as the sealing layer 6 by the CVD method. After forming the protective layer 6, the color filter 7 was formed.

The ratio of the distance of 1.4 μm between the openings of the two adjacent first electrodes to the layer thickness of the organic layer of 76 nm (total of each organic layer) on the first electrode 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 of 80 nm. Further, the layer thickness of the organic layer in the flat portion 22 of 76 nm was lower than the height of the upper end of the inclined portion 32 of 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. Since the minimum wavelength λ of the peaks of the emission spectrum of the light emitting layer is 460 nm, the optical distance L is 146 nm, and the phase difference shift φ is −π, the following equation (8) is satisfied. Equation (8) is derived from the above equation (5).
(Λ / 8) × (− (2φ / π) -1) <L <(λ / 8) × (− (2φ / π) +1) (8)

Further, the organic layer has a hole transport region composed of a hole injection layer and a hole transport layer between the first electrode and the light emitting layer. The height of the upper surface of the charge transport region in the flat portion 21 with respect to the flat portion 21 is 12 nm, which is lower than the height of the upper end of the steeply inclined portion of 50 nm, and the height of the upper surface of the organic layer in the flat portion 21 with respect to the flat portion 21 is 76 nm. Is higher than the height of the upper end of the steeply inclined portion 312, which is 50 nm. Similarly, the height of the upper surface of the charge transport region in the flat portion 22 with respect to the flat portion 22 is lower than the height of 50 nm at the upper end of the steeply inclined portion, and the height of the upper surface of the organic layer in the flat portion 22 with respect to the flat portion 22 is lower than the height of 50 nm. The height of 76 nm is higher than the height of the upper end of the steeply inclined portion 322 of 50 nm.

Next, the characteristics of the formed organic light emitting device 100 of Example 1 will be described. First is indicative for a leakage current between the light emitting _element, a method of measuring _I leak _/ I _oled, it will be exemplified in R pixel. The R pixel is energized with the adjacent G pixel and B pixel short-circuited (potential = 0V, that is, short-circuited). At this time, the current flowing from the first electrode of the R pixel to the second electrode of the R pixel was _{defined as 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 B pixel was _defined as I _leak . .. I _leak was measured at a potential value where I _oled was 0.1 nA / pixel. The ratio of _{I leak} for I _oled, and I leak _{/ I oled.} When I _leak / _OLED was 0.20 or less, it was evaluated that the leakage current was reduced.

Next, the leak current between the upper electrode and the lower electrode will be described. Since the emission threshold voltage of the organic light emitting element is about 2V, a light emitting element that does not generate a leakage current between the upper electrode and the lower electrode can be a current even if a voltage of 1.5V is applied between the upper electrode and the lower electrode, for example. Does not flow. However, in a light emitting element in which a leak current is generated between the upper electrode and the lower electrode, a current flows when a voltage of 1.5 V is applied between the upper electrode and the lower electrode. Therefore, the current value when a voltage of 1.5 V was applied between the upper electrode and the lower electrode of the R pixel was measured. That is, when 1.5 V is applied, the flowing current is a leak current. In the light emitting element in which the leakage current between the upper electrode and the lower electrode is reduced, no current flows even when 1.5 V is applied.

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

As a result, I _leak / _OLED is 0.15, the amount of current when 1.5V voltage is applied is 1 × ^10-6 nA / pixel, and the amount of current when 5V voltage is applied is 16 nA / pixel. The brightness was 250 cd / m ² , and good device characteristics were obtained.

[Comparative Example 1]
The height of the steeply inclined portion 312 with respect to the flat portion 21 was 90 nm, the height of the inclined portion 31 was 120 nm, the height of the steeply inclined portion 322 with respect to the flat portion 22 was 90 nm, and the height of the inclined portion 32 was 120 nm. Except for this, an organic light emitting device was produced in the same manner as in Example 1. The region 41 of the organic layer along the inclined portion 31 is formed not only in the gently inclined portion 311 but also in the region along the steeply inclined portion 312, and the organic layer thickness in the region along the steeply inclined portion is 18 to 18. It was 24 nm. The same was true for the 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 / _OLED could not be measured. Since I _leak is large and I _oled is small, I _leak / I _oleed becomes a very large value and cannot be measured. The amount of current when a 1.5 V voltage was applied was as large as 1 × 10 ^-1 nA / pixel. A phenomenon occurred in which the intensity of light emission decreased at the inner circumference of the opening. It is considered that this is because there was a region where the potential difference between the upper electrode and the lower electrode became small due to the influence of the leak current between the upper electrode and the lower electrode.

From this, it can be seen that when the layer thickness of the region of the organic layer along the inclined portion has a portion of less than 20 nm, the leakage current between the upper electrode and the lower electrode becomes large.

[Comparative Example 2]
The height of the steeply inclined portion 312 with respect to the flat portion 21 was 30 nm, the height of the inclined portion 31 was 50 nm, the height of the steeply inclined portion 322 with respect to the flat portion 22 was 30 nm, and the height of the inclined portion 32 was 50 nm. Except for this, an organic device was produced in the same manner as in Example 1.

As a result, I _leak / _OLED was 0.25, and the amount of current when 1.5 V voltage was applied was below the measurement limit ( ^10-6 nA / pixel). As shown by the I _leak / _OLED being 0.25, the ratio of the leakage current was large, and the leakage current between the light emitting elements was very large.

From this, it can be seen that when the height of the upper surface of the organic layer in the flat portion is lower than the height of the upper end of the inclined portion, the crosstalk between the light emitting elements tends to increase.

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

As a result, the I _leak / I _oled was 0.35, and the amount of current when the 1.5 V voltage was applied was below the measurement limit ( ^10-6 nA / pixel). As shown by the I _leak / _OLED being 0.35, the ratio of the leakage current was large, and the leakage current between the light emitting elements was very large. From this, it can be seen that when the height of the upper surface of the organic layer in the flat portion is lower than the height of the upper end of the inclined portion, the crosstalk between the light emitting elements tends to increase.

Further, since the layer thickness of the electron transport layer was 140 nm and the total film thickness of the organic layer on the lower electrode was 182 nm, which was thicker than that of Example 1, the following formula (8) was not satisfied, and λ / 4 It was not an interference condition.
(Λ / 8) × (− (2φ / π) -1) <L <(λ / 8) × (− (2φ / π) +1) (8)

As a result, the amount of current when a 5 V voltage was applied was 6 nA / pixel, the brightness was 90 cd / m ² , and the amount of current and the brightness were small. It is probable that the resistance increased due to the thickening of the organic layer on the lower electrode.

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

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

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

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

FIG. 13 shows the relationship between the film thickness of the thinnest portion of the film thickness in the direction perpendicular to the inclined portion of the organic layer in the inclined portion 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, the thinnest portion of the film thickness in the direction perpendicular to the inclined portion of the organic layer along the inclined portion 31 and the inclined portion 32. The relationship between the thickness (minimum organic film thickness) and the leakage current between the upper electrode and the lower electrode is shown.

From this, it can be seen that when the layer thickness of the region of the organic layer along the inclined portion has a portion of less than 20 nm, the leakage current between the upper electrode and the lower electrode becomes large. On the contrary, when the layer thickness of the region of the organic layer along the inclined portion is 20 nm or more, the leak current between the upper electrode and the lower electrode is less than 1 × 10 ^-4 nA / pixel, and good characteristics can be maintained. .. Further, when the layer thickness of the region of the organic layer along the inclined portion was 25 nm or more, it was even better at less than 1 × 10 ⁻⁵ nA / pixel.

[Comparative Example 4]
The organic light emitting device was produced in the same manner as in Example 1 except that the shape of the insulating layer was the shape shown in FIG. did. Since the shape of the pixel is a hexagon, the inclined portion 31 is composed of regions 1 to 6 counterclockwise from the right side of the paper surface of FIG. 2 according to the side 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, a phenomenon occurred in which the light emission intensity on the inner circumference of the opening was reduced. Then, the situation of the phenomenon that the emission intensity of the inner circumference of the opening becomes small differs depending on each side of the hexagon. It was found that it was related to the layer thickness of the region of the organic layer along the slope. The results are shown in Table 1.

From this, when the layer thickness of the organic layer region along the inclined portion is 33 nm or more, the phenomenon that the emission intensity of the inner circumference of the opening is reduced does not occur, and the leakage current between the upper electrode and the lower electrode is reduced. You can see that.

1 Substrate 2 Reflective electrode 3 Insulation layer 4 Organic layer 5 Semi-transmissive electrode 6 Protective layer 7 Color filter 8 Flattening layer 9 Transmitted light 10 Light emitting element 100 Organic light emitting device 1000 Display device 1001 Top cover 1002 Flexible print circuit 1003 Touch panel 1004 Flexible print Circuit 1005 Display panel 1006 Frame 1007 Circuit board 1008 Battery 1009 Bottom cover 1100 Image pickup device 1101 Viewfinder 1102 Rear display 1103 Operation unit 1104 Housing 1200 Electronic equipment 1201 Display unit 1202 Operation unit 1203 Housing 1300 Display unit 1301 Frame 1302 Base 1310 Display device 1311 First display unit 1312 Second display unit 1313 Housing 1314 Bending point 1400 Lighting device 1401 Housing 1402 Light source 1403 Circuit board 1404 Optical film 1405 Light diffuser 1500 Automobile 1501 Tail lamp 1502 Window 1503 Body

Claims (22)

A plurality of first electrodes, a second electrode, a functional layer arranged between the first electrode and the second electrode and covering the plurality of first electrodes, and an end of the first electrode are covered. , With an insulating layer having an inclined portion on the first electrode,
The first electrode includes the end of the first electrode and has a first region covered with the insulating layer and a second region in contact with the functional layer.
The functional layer is continuously arranged so as to cover the second region of two adjacent first electrodes of the plurality of first electrodes and the insulating layer covering each of the two first electrodes. Being done
An electronic device in which the layer thickness of the functional layer in the second region is smaller than the height from the upper surface of the first electrode to the upper surface of the insulating layer.
The functional layer in the inclined portion of the insulating layer is an electronic device having a layer thickness of 20 nm or more in the direction perpendicular to the inclined surface of the inclined portion. The ratio of the ratio of the thickness of the functional layer on the second region to the distance between the second region of the first electrode and the second region of the first electrode in the adjacent element is less than 50. The electronic device according to claim 1. In a cross section perpendicular to the main surface of the first electrode, the inclined portion is formed between a gently inclined portion between the upper end of the inclined portion and the lower end of the inclined portion, and between the gently inclined portion and the lower end, and said. The electronic device according to claim 1 or 2, wherein the electronic device has a steeply inclined portion whose inclination angle with respect to the first electrode is larger than the inclination angle of the gently inclined portion. The functional layer has a charge transport layer in contact with the first electrode, and the height of the upper surface 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 according to claim 3, wherein 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. A plurality of first electrodes, a second electrode, a functional layer arranged between the first electrode and the second electrode and covering the plurality of first electrodes, and an end of the first electrode are covered. , With an insulating layer having an inclined portion on the first electrode,
The first electrode includes the end of the first electrode and has a first region covered with the insulating layer and a second region in contact with the functional layer.
The functional layer is continuously arranged so as to cover the second region of two adjacent first electrodes of the plurality of first electrodes and the insulating layer covering each of the two first electrodes. Being done
An electronic device in which the layer thickness of the functional layer in the second region is smaller than the height from the upper surface of the first electrode to the upper surface of the insulating layer.
In the cross section perpendicular to the main surface of the first electrode, the inclined portion of the insulating layer includes a gently inclined portion arranged between the upper end of the inclined portion and the lower end of the inclined portion, and the gently inclined portion. It has a steeply inclined portion between the lower ends and the inclination angle with respect to the first electrode is larger than the inclination angle of the gentlely inclined portion.
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 5, wherein the functional layer in the gently inclined portion of the insulating layer has a layer thickness of 20 nm or more in the direction perpendicular to the inclined surface of the gently inclined portion. The invention according to any one of claims 1 to 6, wherein the inclined portion and the first region of the first electrode overlap each other in a plan view from a direction perpendicular to the main surface of the substrate. Electronic device. The insulating layer is covered with the functional layer and has another inclined portion different from the inclined portion, and the other inclined portion is the first in a plan view from a direction perpendicular to the main surface of the substrate. Placed between one electrode and the other first electrode,
The electronic device according to any one of claims 1 to 7, wherein the functional layer in the other inclined portion has a layer thickness of 20 nm or more in the direction perpendicular to the other inclined portion. The electron according to any one of claims 1 to 4, wherein in the plurality of the insulating layers, the thickness of the functional layer in the direction perpendicular to the inclined portion in the inclined portion is 20 nm or more. device. The electron according to claim 9, wherein in the plurality of the insulating layers, the thickness of the functional layer in the direction perpendicular to the inclined surface of the other inclined portion in the other inclined portion is 20 nm or more. device. The inclined surface in the inclined portion is not parallel to the upper surface of the first electrode,
Claim 1 is characterized in that the inclined surface in 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 covered by the insulating layer. 10. The electronic device according to any one of 10. The third or fifth aspect of the present invention, wherein the inclination angle of the steeply inclined portion with respect to the first electrode is larger than 50 °, and the inclination angle of the gently inclined portion with respect to the first electrode is 50 ° or less. Electronic device. The electronic device according to claim 3 or 5, wherein the insulating layer includes a portion where the inclination angle of the steeply inclined portion with respect to the first electrode is larger than 90 °. The electronic device according to any one of claims 1 to 13, wherein the functional layer is an organic layer having a light emitting layer. The electronic device according to claim 14, wherein the charge transport layer is a hole transport layer, and the light emitting layer is an electron trap type. The present invention is characterized in that the first electrode is a reflecting electrode, the second electrode is a light extraction electrode, and the optical distance L between the reflecting electrode and the light extraction electrode satisfies the formula (1). Item 14. The electronic device according to item 14 or 15.
(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 at the reflecting electrode. The electronic device according to any one of claims 1 to 16, wherein the functional layer is an organic layer having a photoelectric conversion layer. It has a plurality of pixels, and at least one of the plurality of pixels has the electronic device according to any one of claims 1 to 17 and a transistor connected to the electronic device. Display device. It has 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, wherein the display unit includes the electronic device according to any one of claims 1 to 17. Having a display unit having the electronic device according to any one of claims 1 to 17, a housing provided with the display unit, and a communication unit provided in the housing and communicating with the outside. An electronic device characterized by. A lighting device comprising a light source having the electronic device according to any one of claims 1 to 17, and a light diffusing unit or an optical film that transmits light emitted by the light source. A moving body having a lamp having the electronic device according to any one of claims 1 to 17 and an airframe provided with the lamp.

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