JP2010129452A - Organic light-emitting element, and display device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic light-emitting element which has high luminous efficiency and is small in view angle dependency of light-emitting characteristics of the element. <P>SOLUTION: In the organic light-emitting element in which light going toward a light extraction electrode 103 from a light-emitting layer 105, and light which is emitted from the light-emitting layer 105 and reflected by a reflecting face on a reflecting electrode 102 side from the light-emitting layer 105 are interfered with each other. In the reflecting electrode 102 or on the opposite side of the light-emitting layer 105 side of the light extraction electrode 103, this has a resonance part (for example, dielectric layer 102B) to resonate light emitted from the light-emitting layer 105, and a film thickness d<SB>1</SB>of the resonance part satisfies a formula: m<SB>1</SB>+1/2<(2n<SB>1</SB>d<SB>1</SB>/λ)+ϕ/2π<m<SB>1</SB>+3/4 against the refractive index n<SB>1</SB>of the resonance part, the maximum peak wavelength λ of a spectrum of light extracted outside of the organic light-emitting element, a phase shift ϕ caused when light emitted from the light-emitting layer 105 is reflected on both ends of the resonance part, and an integer m<SB>1</SB>. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic light emitting element and a display device using the same.

  Organic light-emitting elements (hereinafter sometimes referred to as elements) are characterized by thin films and self-light emission, and are applied as new-type flat panel displays.

  The organic light emitting device is composed of a pair of electrodes composed of a cathode and an anode, and an organic compound layer formed between the pair of electrodes. The organic light emitting device emits light by injecting electrons from the cathode and holes from the anode into the organic compound layer, generating excitons in the light emitting layer in the organic compound layer, and the molecules in the light emitting layer are excited by the excitons. The principle is that light is emitted when the molecule returns from the excited state to the ground state. The light emitting layer is made of a light emitting material such as a fluorescent organic compound, a phosphorescent organic compound, or a quantum dot.

Until now, in the organic light emitting device, in order to improve the color purity and luminous efficiency of the luminescent color, a resonator structure as in Patent Document 1 has been introduced. In an element having a resonator structure, light having a resonance wavelength is amplified and extracted outside the element. For this reason, the intensity of the peak wavelength of the spectrum of light extracted outside the element is large, and light having a narrow spectrum width can be extracted.
Japanese Patent Laid-Open No. 2004-127795

  However, in the organic light emitting device having the resonator structure described above, since the interference effect is strong, when the light emitting surface is viewed from an oblique direction, the wavelength of the extracted light is shifted to the short wavelength side, or the light emission intensity is high. There is a problem that the viewing angle dependency of the light emission characteristic becomes large when the light emission characteristic is lowered. This is considered to be due to the fact that the optical path lengths of the light extracted from the front surface of the light emitting surface and the light extracted obliquely from the light emitting surface are different and the wavelengths of the light enhanced by the resonator structure are different.

  In general, in order to improve luminous efficiency, the electrode on the side opposite to the light extraction side of the pair of electrodes constituting the element is made of a highly reflective metal, or the reflective layer and the transparent conductive material. In many cases, the layers are laminated. For this reason, since the light emitted from the light emitting layer toward the light extraction side and the light emitted from the light emitting layer and reflected from the electrode having a high reflectance on the side opposite to the light extraction side and the reflection layer interfere with each other, the resonator Even the organic light emitting element having no structure causes the above-described problem.

  In view of the above problems, an object of the present invention is to provide an organic light-emitting device with high efficiency and low viewing angle dependency of light-emitting characteristics of the device.

In order to solve the above problems, an organic light-emitting device of the present invention includes a reflective electrode composed of a plurality of layers, an organic compound layer having a light-emitting layer, and a light extraction electrode in this order. An organic light emitting element in which light emitted from the light emitting layer interferes with light emitted from the light emitting layer and reflected by a reflective surface on the reflective electrode side from the light emitting layer, On the opposite side to the light emitting layer side, there is a resonance part that resonates light emitted from the light emitting layer, and the film thickness d ₁ of the resonance part is the refractive index n _{1 of} the resonance part, the outside of the organic light emitting element The maximum peak wavelength λ of the spectrum of the light extracted to the phase, the phase shift φ that occurs when the light emitted from the light emitting layer is reflected at both ends of the resonance part, and the integer m ₁

It is characterized by satisfying.

  According to the present invention, it is possible to realize an organic light emitting device with high efficiency and low viewing angle dependency of light emitting characteristics of the device.

  Hereinafter, the principle of the present invention will be described based on structural examples. The resonator structure is composed of one layer or a plurality of layers and two reflecting surfaces at both ends of the one layer or both layers. Refers to a structure in which light is subjected to multiple interference. The resonating part refers to one layer or a plurality of layers constituting the resonator structure.

  FIG. 1 shows a schematic cross-sectional view of the organic light-emitting device of the present invention. In addition, although the organic light emitting element was shown in the example of illustration, even if it is a QD-LED element etc., it can implement. In the organic light-emitting element shown in FIG. 1, a reflective layer 102A, a dielectric layer 102B, and a transparent conductive layer 102C are laminated on a substrate 100, and a reflective electrode 102 serving as an anode is formed. On the reflective electrode 102, an organic compound layer 101 having a light emitting layer 105 is formed, and a light extraction electrode 103 serving as a cathode is further formed. The light extraction electrode is a transparent or translucent electrode having light transmittance in order to extract light emitted from the light emitting layer out of the device. As used herein, “light transmission” refers to a property having a transmittance of 50 to 100% with respect to visible light.

The reflective layer 102A is made of an Al alloy, an Ag alloy, or the like. The reflective layer 102 preferably has a high reflectance of 75% or more in the spectral reflectance in the visible light wavelength region (λ = 380 nm to 780 nm). The dielectric layer 102B is made of light transmissive SiO ₂ , SiO, SiN _x O _y , acrylic resin, or the like. The transparent conductive layer 102C is a transparent oxide conductive layer such as ITO or IZO. As the light extraction electrode 103, a transparent oxide conductive layer similar to the transparent conductive layer 102C can be used, and as an electrode (metal translucent electrode) made of a metal thin film such as Ag, Al, Ag alloy, Al alloy or the like. Also good. Alternatively, the light extraction electrode 103 may be an electrode having a laminated structure of a transparent oxide conductive layer and a metal thin film.

  As shown in FIG. 1, the organic compound layer 101 usually has a structure in which a hole transport layer 106, a light emitting layer 105, and an electron transport layer 107 are laminated. In addition, the organic compound layer may be configured only of the light emitting layer, and if necessary, a hole injection layer is provided between the anode and the hole transport layer, and an electron injection layer is provided between the cathode and the electron transport layer. May be. That is, the organic compound layer has at least a light emitting layer, and has a configuration having one or more of functional layers such as a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer as necessary. Also good. The organic compound layer may have a plurality of functional layers having the same function. The light emitting layer 105 contains a fluorescent organic compound or a phosphorescent organic compound corresponding to each emission color.

  When a voltage is applied between the reflective electrode 102 and the light extraction electrode 103 constituting the organic light emitting device, holes are injected from the anode (reflective electrode 102) and electrons are injected from the cathode (light extraction electrode 103) into the organic compound layer 101. . The injected holes and electrons form excitons in the light emitting layer 105, and the molecules in the light emitting layer are excited by the excitons, and light is emitted when the molecules return from the excited state to the ground state. Here, in the configuration example of the organic light emitting element shown in FIG. 1, light is extracted from the light extraction electrode 103 side to the outside of the element with respect to the light generated in the light emitting layer 105.

  The reflective electrode 102 has a dielectric layer 102B made of a material having a refractive index different from that of the transparent conductive layer 102C between the reflective layer 102A and the transparent conductive layer 102C. In this case, the dielectric layer 102B is an intermediate layer located between the reflective layer 102A and the organic compound layer 101. By changing the optical path length of the dielectric layer 102B, the reflectance with respect to the emitted light at the interface between the reflective electrode 102 and the organic compound layer 101 can be adjusted.

  In the organic light emitting device, light emitted from the light emitting layer and directed to the light extraction electrode, light emitted from the light emitting layer, and reflected by the reflective surface on the reflective electrode side (in this case, the interface between the reflective electrode and the organic compound layer). Due to the interference effect with light, the light emission efficiency of light emitted from the light emitting layer is increased, and the color purity is improved. When viewed from an angle inclined from the light emitting surface of the device, the maximum peak wavelength of the interference intensity distribution obtained by this interference effect shifts to the short wavelength side (short wavelength shift) as the angle increases. For this reason, in the organic light emitting device using the interference effect, the viewing angle dependency of the light emission characteristics of the device is increased, and the light chromaticity when viewed from the front of the light emitting surface and the angle inclined from the light emitting surface are viewed. In this case, the chromaticity deviation from the chromaticity of the light becomes large. In general, when the reflectance of the reflective electrode is increased, the interference effect is enhanced, so that the light emission efficiency is improved, while the viewing angle dependency of the light emission characteristics of the organic light emitting element is increased.

  The organic light-emitting device of the present invention has a dielectric layer so that the reflectance at the interface between the reflective electrode 102 and the organic compound layer 101 increases as the angle at which light is extracted with respect to the front surface increases. The optical path length of 102B is adjusted. At the same time, the optical path length of the dielectric layer 102B is adjusted so that the reflectance at the interface between the reflective electrode 102 having the maximum peak wavelength of light extracted outside the element and the organic compound layer 101 does not decrease.

  That is, the organic light emitting device of the present invention is tilted from the front while increasing the maximum peak wavelength intensity of light extracted outside the device by setting the film thickness of the dielectric layer 102B in the reflective electrode 102 as desired. The short wavelength shift of the light extracted at a certain angle is suppressed.

  As a result, the light emission efficiency of the organic light emitting device can be improved, and at the same time, the viewing angle dependence of the light emission characteristics of the device can be reduced.

The principle of the present invention will be described in more detail. As shown in FIG. 1, the complex reflection coefficient at the interface between the reflective electrode 102 and the organic compound layer 101 is r ₋ = | r ₋ | exp (iφ ₋ ). Further, the complex reflection coefficient at the interface of the light extraction electrode 103 on the light extraction side (the surface opposite to the interface between the light extraction electrode 103 and the electron transport layer 107) is expressed as r ₊ = | r ₊ | exp (iφ ₊ ). And Here, it is assumed that the domain of phase shift is −π <φ ₋ , φ ₊ ≦ π. Further, the distance between the reflective electrode 102 and the light extraction side interface of the light extraction electrode 103 is d, and the average refractive index of each layer therebetween is n, and the distance between the reflection electrode 102 and the light emitting point 108 in the light emitting layer 105 is Is d ₋ , and the average refractive index of the layer between them is n ₋ .

  The light emission intensity I (λ) of the organic light emitting device is that the maximum peak wavelength of the spectrum of light extracted from the light emitting layer 105 to the outside of the organic light emitting device is λ, the wave number is k = 2π / λ, If the angle taken out is θ, it is given by Equation 2.

From the phase part of the denominator of Equation 2, the phase condition for strengthening multiple interference is given by Equation 3 for the integer m. Further, the phase part of the number 2 of the molecule, the integer m _- relative to the phase condition for the wide-angle interference constructive is given by the number 4. From these, it can be seen that as the angle θ from which light is extracted increases, the wavelengths that are strengthened by interference shift by a short wavelength, resulting in a chromaticity shift. Usually, in order to improve the emission intensity of light extracted to the front (θ = 0), the reflecting surface (the interface between the reflective electrode 102 and the organic compound layer 101 and the interface on the light extraction side of the light extraction electrode 103). , That is, the absolute values of the complex reflection coefficients | r ₋ | and | r ₊ | are increased. As a result, the emission intensity of the light extracted to the front (θ = 0) is improved, and the viewing angle dependency of the extracted emission color is increased.

In the present invention, the absolute value | r ₋ | of the complex reflection coefficient of the reflective electrode 102 at the maximum peak wavelength λ increases so that the viewing angle dependency is reduced as the angle θ at which light is extracted increases. To do. That is, the increase in the absolute value | r ₋ | of the complex reflection coefficient compensates for the decrease in the intensity of interference at the maximum peak wavelength λ of the light extracted outside the device as the extracted angle θ increases. Thus, the viewing angle dependency of the emission intensity I (λ) is reduced. This is to adjust the optical path length of the dielectric layer 102B so that the reflectance at the interface between the reflective electrode 102 and the organic compound layer 101 is increased by interference at a wavelength longer than the maximum peak wavelength λ. Is possible. This condition is given by Equation 5. Here, in the configuration of FIG. 1, the complex reflection coefficient at the interface between the reflective layer 102A and the dielectric layer 102B is r ₁ = | r ₁ | exp (iφ ₁ ), and the dielectric layer 102B and the transparent conductive layer 102C The complex reflection coefficient of the interface was r ₂ = | r ₂ | exp (iφ ₂ ). Further, the thickness of the dielectric layer 102B is d ₁ , and the refractive index of the dielectric layer 102B is n ₁ . m ₁ is an integer. In this organic light emitting device, a resonator structure in which light generated in the light emitting layer 105 interferes multiplely between the interface between the reflective layer 102A and the dielectric layer 102B and the interface between the dielectric layer 102B and the transparent conductive layer 102C. can get. That is, in this case, the resonance part of the resonator structure is the intermediate layer in the reflective electrode 102, that is, the dielectric layer 102B.

However, the greater the thickness d ₁ of the dielectric layer 102B, the maximum peak wavelength λ of light extracted out of the element, reduced to increase the reflectance at the interface between the reflective electrode 102 and the organic compound layer 101 End up. For this, the film thickness d ₁ of the dielectric layer 102B may be to satisfy Equation 6. Equation 6 is the maximum peak wavelength λ of the light spectrum extracted outside the device. The reflectance of the reflective electrode 102 as a whole is enhanced by multiple interference in the dielectric layer 102B, and the light emission intensity of the organic light emitting device is improved. is there. When the condition given by Equation 6 is satisfied, the intensity of the maximum peak wavelength λ of the light emitted from the light emitting layer becomes weaker in the dielectric layer 102B, and accordingly, on the light extraction side than the dielectric layer 102B. The intensity of the maximum peak wavelength λ is increased. Therefore, the reflectance with respect to the maximum peak wavelength λ of the entire reflective electrode 102 is increased.

Therefore, from Equations 5 and 6, the condition of the film thickness of the dielectric layer 102B for improving the emission intensity and reducing the viewing angle dependency in the organic light emitting device is given by Equation 7. In the present invention, the thickness d ₁ of the dielectric layer 102B has been adjusted to meet the number 7 conditions. However, in Equation 7, φ = φ ₁ + φ ₂ . This φ occurs when the light emitted from the light emitting layer 105 is reflected at both ends of the resonance part (the interface between the reflective layer 102A and the dielectric layer 102B and the interface between the dielectric layer 102B and the transparent conductive layer 102C). It can be called a phase shift.

When the absolute value | m ₁ | increases, the integer m ₁ increases the viewing angle dependency of the light emission color of the device or decreases the light emission efficiency. Therefore, when | m ₁ | = 0, 1, It is desirable to adjust the film thickness of the dielectric layer 102 </ b> B to satisfy 7.

  In the above description, the reflection electrode 102 is an anode and the light extraction electrode 103 is a cathode. However, the reflection electrode 102 may be a cathode and the light extraction electrode 103 may be an anode. In this case, the hole transport layer 106 and the electron transport layer 107 may be positioned opposite to the light emitting layer 105.

Further, when the refractive index n ₁ of the dielectric layer 102B which is the resonance part is different from the refractive index of the two layers adjacent to the resonance part, the effect of multiple interference in the resonator structure becomes larger, and the reflection electrode 102 as a whole becomes more effective. This is advantageous because it has the effect of increasing the reflectance. In order to further increase the effect of multiple interference in the resonator structure, the refractive index between the dielectric layer 102B and the transparent conductive layer 102C is higher than the refractive index ratio between the transparent conductive layer 102C and the hole transport layer 106 in the configuration of FIG. The dielectric layer 102B is preferably formed of a material that increases the ratio.

  Up to now, the dielectric layer 102B has been described as an example of the intermediate layer. However, the intermediate layer may be a layer having a light transmitting property even if it is not a layer made of a dielectric. The refractive index of the material constituting the intermediate layer is preferably different from the refractive indexes of the reflective layer 102A and the transparent conductive layer 102C. Further, the intermediate layer is preferably a layer made of a material that makes the refractive index ratio between the intermediate layer and the transparent conductive layer 102C larger than the refractive index ratio between the transparent conductive layer 102C and the hole transport layer 106.

In the configuration of FIG. 1, when the dielectric layer 102B is not configured, the effect of the present invention can be obtained by setting the resonance portion as the transparent conductive layer 102C and appropriately setting the film thickness of the transparent conductive layer 102C. Specifically, the film thickness d ₂ of the transparent conductive layer 102C is such that the refractive index n ₂ of the transparent conductive layer 102C, the phase shift φ _t generated when the light emitted from the light emitting layer 105 is reflected at both ends of the resonance part, for integer m _2, it is sufficient to satisfy the number 8. In this case, both ends of the resonance part are an interface between the transparent conductive layer 102C and the organic compound layer 101 and an interface between the transparent conductive layer 102C and the reflective layer 102A.

In FIG. 1, the dielectric layer 102 </ b> B and the transparent conductive layer 102 </ b> C may both be a resonance part in the reflective electrode 102. In this case, satisfying the thickness d ₁ is the number 7 of the dielectric layer 102B, furthermore, if such thickness d ₂ of the transparent conductive layer 102C satisfies Equation 8, more effect of the present invention is high. In this configuration, in Equation 8, the phase shift φ _t occurs when light is reflected at the interface between the transparent conductive layer 102C and the organic compound layer 101 and at the interface between the transparent conductive layer 102C and the dielectric layer 102B. Note that Further, the resonance part is a dielectric layer 102B and a transparent conductive layer 102C which are intermediate layers.

  On the other hand, in FIG. 1, the dielectric layer 102 </ b> B is not used as a resonating part, and only the transparent conductive layer 102 </ b> C is used as the resonating part.

Further, as shown in FIG. 2, the reflective electrode 102 may have a structure in which the transparent conductive layer 102C, the metal thin film layer 102D, the dielectric layer 102B, and the reflective layer 102A are arranged in this order from the organic compound layer 101 side. In the configuration of FIG. 1, the “reflecting surface on the reflective electrode 102 side from the light emitting layer 105” is the interface between the transparent conductive layer 102C and the organic compound layer 101. However, in the configuration of FIG. And the metal thin film layer 102D. In this configuration, the resonance unit is a dielectric layer 102B, as the thickness d ₁ of the dielectric layer 102B satisfies Expression 7, by forming the dielectric layer 102B, the effect of the present invention. In this case, in Equation 7, the phase shift φ is generated when light is reflected at the interface between the dielectric layer 102B and the metal thin film layer 102D and the interface between the dielectric layer 102B and the reflective layer 102A. warn. And as this metal thin film layer 102D, it is preferable to use Al alloy and Ag alloy, and the thickness has preferable 10-20 nm. Even in this configuration, the refractive indexes of the dielectric layer 102B and the metal thin film layer 102D are different.

Further, as shown in FIG. 3, the metal translucent electrode 103 </ b> B (light extraction electrode) has a resonance part (for example, the dielectric layer 104) on the side opposite to the light emitting layer 105 side (light extraction side), and the resonance Even if the film thickness of the portion is defined, the effect of the present invention is obtained. In this case, the refractive index of the resonance part is n ₁ , the maximum peak wavelength of the spectrum of light extracted outside the element is λ, and the phase shift that occurs when the light emitted from the light emitting layer 105 is reflected at both ends of the resonance part is φ Then, the resonance part may be formed with a film thickness d ₁ that satisfies Equation 7 with respect to the integer m ₁ . At this time, the phase shift φ occurs when light is reflected at the interface between the resonance part and the metal translucent electrode 103B and the surface opposite to the resonance part and the metal translucent electrode 103B. warn.

  1, 2, and 3, the top emission type organic light emitting element that extracts light from the side opposite to the substrate 100 has been described as an example. However, the bottom emission type organic light emitting element that extracts light from the substrate 100 side is described. Even so, the effects of the present invention can be obtained. In this case, the stacking order of the reflective electrode 102 and the light extraction electrode 103 with respect to the substrate 100 may be changed. That is, the light extraction electrode 103, the organic compound layer 101, and the reflection electrode 102 on the light extraction side are sequentially stacked from the substrate 100 side.

  The organic compound used in each layer of the organic compound layer 101 is composed of a low molecular material, a high molecular material, or both, and is not particularly limited. Furthermore, a layer made of only an inorganic compound may be included as necessary.

  If necessary, a light-transmitting protective layer may be laminated between the reflective layer 102A and the dielectric layer 102B in order to prevent deterioration and damage in the sputtering process.

  The organic light emitting device of the present invention can be used as a light emitting device constituting a display device. Specifically, the display device is a display of an electronic device such as a television receiver, a display of a personal computer, a rear display unit of an imaging device, a display unit of a mobile phone, a display unit of a portable game machine. The display device includes a plurality of organic light emitting elements and a drive circuit that controls light emission of each of the plurality of organic light emitting elements, and the organic light emitting device of the present invention is used as at least one of the plurality of organic light emitting elements. If the element is used, a display device in which the light emission characteristics have a small viewing angle dependency can be obtained.

Example 1
In FIG. 4, the reflective electrode 102A is made of an Al alloy, the dielectric layer 102B is made of SiO ₂ (refractive index 1.46), and the transparent conductive layer 102C is made of IZO (film thickness 60 nm, refractive index 1.95). The organic light emitting element which light-emits green which has this. In this element, an example of calculation results of luminance and chromaticity deviation with respect to a change in film thickness of the dielectric layer 102B is shown. At this time, λ = 520 nm and φ / (2π) = − 0.3951 + 0.5 = 0.1049. Further, the thickness of the dielectric layer 102B is changed from 0 nm to 160 nm. In order to compare the luminous efficiency by luminance, the film thickness of the hole transport layer 106 (refractive index 1.80) is adjusted so that the CIE chromaticity is constant at (0.21, 0.70). The thickness of each layer other than the dielectric layer 102B and the hole transport layer 106 is the same. The solid line in FIG. 4 shows a change in luminance with respect to the film thickness d ₁ of the dielectric layer 102B, the thickness d ₁ of the dielectric layer 102B is a reference value of 0. Broken line in FIG. 4 shows a chromaticity shift Δxy luminous color to be taken out to outside the element with respect to the film thickness d ₁ of the dielectric layer 102B. This chromaticity shift Δxy is defined as CIE chromaticity coordinates of θ = 0 (front), (x0, y0), and CIE chromaticity coordinates of an angle of θ ° ≦ 60 °, where θ is the angle at which light is extracted (θ). xθ, yθ) is defined by Equation 9. The smaller the chromaticity shift Δxy, the smaller the viewing angle change of the chromaticity of the emitted color.

In FIG. 4, the region indicated by the dot is a region that satisfies the condition of Equation 7 when m ₁ = 0, and the luminous efficiency (luminance) is improved and at the same time, the chromaticity shift of the emitted color is suppressed, and the element It can be seen that the viewing angle dependence of the emission characteristics is reduced.

(Example 2)
FIG. 5 shows a dielectric in the case of an organic light emitting device that emits blue light having a reflective electrode 102 in which the reflective layer 102A is made of an Ag alloy, the dielectric layer 102B is made of SiO ₂ , and the transparent conductive layer 102C is made of IZO (50 nm). An example of calculation results of luminance and chromaticity deviation with respect to a change in film thickness of the layer 102B is shown. At this time, λ = 460 nm, φ / (2π) = − 0.3012 + 0.5 = 0.10988. Further, in this embodiment, by changing the thickness _{d 1} of the dielectric layer 102B from 0nm to 100 nm. In addition, in order to compare the luminous efficiency by luminance, the film thickness of the hole transport layer 106 is adjusted so that the CIE chromaticity is constant at (0.135, 0.09). The thickness of each layer other than the dielectric layer 102B and the hole transport layer 106 is the same. The solid line in FIG. 5 is a luminance change with respect to the film thickness d ₁ of the dielectric layer 102B, a broken line indicates a chromaticity deviation Δxy luminous color to be taken out to outside the element with respect to the film thickness d ₁ of the dielectric layer 102B. In FIG. 5 as well, the region indicated by the dot is a region that satisfies the condition of Equation 7 when m ₁ = 0, and the luminous efficiency (luminance) is improved, and at the same time, the change in chromaticity of the emitted color is suppressed. I understand.

  Therefore, according to the present invention, it is possible to improve the light emission efficiency of the organic light emitting device and reduce the viewing angle dependency of the light emission characteristics of the light extracted outside the device.

It is a schematic sectional drawing of the organic light emitting element of this invention. It is a schematic sectional drawing of the other example of the organic light emitting element of this invention. It is a schematic sectional drawing of the other example of the organic light emitting element of this invention. 2 is a calculation result example of luminance and chromaticity deviation of an organic light emitting element that emits green light with respect to a change in film thickness of a dielectric layer in the organic light emitting element shown in FIG. 1. 3 is a calculation result example of luminance and chromaticity shift of an organic light emitting element that emits blue light with respect to a change in film thickness of a dielectric layer in the organic light emitting element shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Substrate 101 Organic layer 102 Reflective electrode 102A Reflective layer 102B, 104 Dielectric layer 102C Transparent conductive layer 102D Metal thin film layer 103 Light extraction electrode 103B Metal translucent electrode 105 Light emitting layer 106 Hole transport layer 107 Electron transport layer 108 Light emitting point

Claims (5)

A reflective electrode composed of a plurality of layers, an organic compound layer having a light emitting layer, and a light extraction electrode are in this order.
An organic light emitting device in which light traveling from the light emitting layer toward the light extraction electrode and light emitted from the light emitting layer and reflected by a reflective surface on the reflective electrode side from the light emitting layer interfere with each other,
In the reflective electrode or on the side opposite to the light emitting layer side of the light extraction electrode, there is a resonance part that resonates light emitted from the light emitting layer,
The thickness d ₁ of the resonance part is such that the refractive index n _{1 of} the resonance part, the maximum peak wavelength λ of the spectrum of light extracted outside the organic light emitting device, and the light emitted from the light emitting layer are at both ends of the resonance part For the phase shift φ and integer m ₁ that occur when reflecting at

An organic light emitting element characterized by satisfying   The reflective electrode has a transparent conductive layer, an intermediate layer, and a reflective layer in this order from the organic compound layer side, and the resonance part is the intermediate layer and / or the transparent conductive layer. The organic light emitting device according to claim 1.   The reflective electrode has a transparent conductive layer, a metal thin film layer, an intermediate layer, and a reflective layer from the light emitting layer side, and the resonance part is the intermediate layer. The organic light emitting element as described.   The organic light-emitting element according to claim 1, wherein the reflective electrode includes a transparent conductive layer and a reflective layer in order from the organic compound layer side, and the resonance part is the transparent conductive layer. A display device comprising a plurality of organic light emitting elements and a drive circuit for controlling light emission of each of the plurality of organic light emitting elements,
5. The display device according to claim 1, wherein at least one of the plurality of organic light emitting elements is the organic light emitting element according to claim 1.

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