WO2011062351A1 - Organic light-emitting diode comprising a black micro-cavity - Google Patents

Organic light-emitting diode comprising a black micro-cavity Download PDF

Info

Publication number
WO2011062351A1
WO2011062351A1 PCT/KR2010/005040 KR2010005040W WO2011062351A1 WO 2011062351 A1 WO2011062351 A1 WO 2011062351A1 KR 2010005040 W KR2010005040 W KR 2010005040W WO 2011062351 A1 WO2011062351 A1 WO 2011062351A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
organic light
light emitting
emitting diode
electrode layer
Prior art date
Application number
PCT/KR2010/005040
Other languages
French (fr)
Korean (ko)
Inventor
도영락
이용희
조상환
Original Assignee
국민대학교 산학협력단
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 국민대학교 산학협력단 filed Critical 국민대학교 산학협력단
Publication of WO2011062351A1 publication Critical patent/WO2011062351A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/80—Constructional details
    • H10K59/875—Arrangements for extracting light from the devices
    • H10K59/878—Arrangements for extracting light from the devices comprising reflective means
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/80—Constructional details
    • H10K59/875—Arrangements for extracting light from the devices
    • H10K59/876—Arrangements for extracting light from the devices comprising a resonant cavity structure, e.g. Bragg reflector pair
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/80—Constructional details
    • H10K59/8791—Arrangements for improving contrast, e.g. preventing reflection of ambient light
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K2102/00—Constructional details relating to the organic devices covered by this subclass
    • H10K2102/301—Details of OLEDs
    • H10K2102/351—Thickness

Definitions

  • the present invention relates to an organic light emitting diode, and more particularly, to an organic light emitting diode having increased brightness and improved contrast ratio.
  • Organic light emitting diodes are self-light emitting devices using organic light emitting materials that emit light when an electric field is applied.
  • the organic light emitting diode includes a positive electrode and a negative electrode, and an organic light emitting layer formed therebetween.
  • When a voltage is applied between the positive electrode and the negative electrode holes are injected from the positive electrode into the organic light emitting layer, and electrons are injected from the negative electrode into the organic light emitting layer. Holes and electrons injected into the organic light emitting layer combine in the organic light emitting layer to generate excitons, and light is emitted as the excitons transition from the excited state to the ground state.
  • the front emission type organic light emitting diode uses a material that can reflect light to the positive electrode and a material that can transmit light to the negative electrode so that the light generated in the organic light emitting layer is effectively emitted to the front surface of the organic light emitting diode.
  • the positive electrode is made of a material having excellent reflection characteristics, the problem of lowering the contrast ratio occurs. In other words, the external light flowing to the front surface is reflected from the positive electrode, and the contrast ratio is reduced. 1 is a view for explaining the reason why the contrast ratio is lower in the conventional front emission type organic light emitting diode. Referring to FIG.
  • a conventional front emission type organic light emitting diode includes a positive electrode 101 having excellent reflection characteristics, a negative electrode 103 having high light transmittance, an organic light emitting layer 102 and a glass substrate 104 formed between the positive electrode and the negative electrode. It includes. External light is introduced from the front surface of the front emission type organic light emitting diode, and the external light is reflected by the positive electrode 101 made of a material having excellent reflection characteristics and is emitted to the front surface again.
  • 2 illustrates external light reflection characteristics of an organic light emitting diode including a positive electrode having excellent reflection characteristics. Referring to FIG. 2, in the case of the conventional front emission type organic light emitting diode, the reflectivity of light in the visible light region is nearly 60 to 70%. This externally reflected external light causes the pixels to be turned off to reflect a certain level of light, which lowers the contrast ratio and consequently degrades the performance of the display device.
  • FIG. 3 is a view for explaining a front emission type organic light emitting diode using a circular polarizer.
  • the organic light emitting diode includes a positive electrode 101, a negative electrode 103, an organic light emitting layer 102, and a glass substrate 104, and a circular polarization layer on the entire surface of the glass substrate 104. 105 is formed. External light flowing from the front surface of the organic light emitting diode passes through the circular polarization layer 105 and is not reflected to the outside.
  • the circularly polarized layer 105 may include protective layers 105a and 105c, linearly polarized layer 105b, adhesive layers 105d and 105f, and quarter-wave layer 105e. ).
  • the external light passes only the polarization in a predetermined direction and does not pass through the polarization in the other direction.
  • the polarized light passing through the linear polarized layer passes through the quarter wavelength layer and is reflected by the mirror. In the process, the direction of the polarized light is changed by 90 ° and thus cannot pass through the linear polarized layer.
  • the circularly polarized layer prevents external light from being reflected from the organic light emitting diode, thereby increasing the brightness and contrast ratio of the organic light emitting diode.
  • the organic light emitting diode using the circular polarizing layer has a transmittance of 40 to 45% of the linear polarizing layer, more than 50% of the light emitted from the organic light emitting layer is absorbed by the linear polarizing layer, and thus the luminance is lowered. Since the thickness of is also about 0.2mm thick to increase the overall thickness of the display device, there is a problem that it is difficult to fabricate the integrated device because an additional process is required.
  • an object of the present invention is to provide a front emission type organic light emitting diode capable of increasing the brightness of the organic light emitting diode and improving the contrast ratio.
  • the present invention includes a reflective electrode layer, an organic light emitting layer formed on the lower surface of the reflective electrode layer, a transparent electrode layer formed on the lower surface of the organic light emitting layer, and a black microcavity formed on the lower surface of the transparent electrode layer, the black
  • the microcavity provides an organic light emitting diode in which a first metal layer, a dielectric layer, and a second metal layer are sequentially stacked on a lower surface of the transparent electrode layer.
  • the reflectivity of the first metal layer is preferably higher than the reflectivity of the second metal layer.
  • the absorbance of the first metal layer is preferably lower than the absorbance of the second metal layer.
  • the first metal layer is any one or more metals or alloys thereof selected from the group consisting of Al, Ag and Au
  • the second metal layer is Cr, Mo, Ti, Co and It may be any one or more metals or alloys thereof selected from the group consisting of Ni.
  • the thicknesses of the first electrode layer, the dielectric layer, and the second electrode layer of the black microcavity may be set such that the light reflected from each of the first electrode layer, the dielectric layer, and the second electrode layer is caused to cancel each other. Can be.
  • the thickness of the transparent electrode layer may be set so that light generated in the organic light emitting layer may resonate between the reflective electrode layer and the first metal layer.
  • the reflective electrode layer may be made of aluminum or silver.
  • the transparent electrode layer may be made of indium tin oxide.
  • the black microcavity applied to the present invention simultaneously implements the microcavity function of resonating the light emitted from the organic light emitting layer and the black film function of absorbing external light, thereby simultaneously achieving the effect of increasing the brightness and improving the contrast ratio. To be able.
  • 1 is a view for explaining the reason why the contrast ratio is lower in the conventional front emission type organic light emitting diode.
  • FIG. 2 illustrates external light reflection characteristics of an organic light emitting diode including a positive electrode having excellent reflection characteristics.
  • FIG. 3 is a view for explaining a front emission type organic light emitting diode using a circular polarizer.
  • FIG. 4 is a cross-sectional view of an organic light emitting diode of the present invention.
  • FIG. 5 is a view for explaining the resonance of light caused by the microcavity and the extinction interference of external light by the black film in the organic light emitting diode of the present invention.
  • the organic light emitting diode of the present invention includes a reflective electrode layer, an organic light emitting layer formed on the lower surface of the reflective electrode layer, a transparent electrode layer formed on the lower surface of the organic light emitting layer, and a black microcavity formed on the lower surface of the transparent electrode layer, wherein the black microcavity is The first metal layer, the dielectric layer, and the second metal layer are sequentially stacked on the lower surface of the transparent electrode layer.
  • the organic light emitting diode of the present invention can implement a black film function that can improve the microcavity and the contrast contrast which can increase the luminance by the above structural features.
  • the microcavity traps light between the two reflective layers and causes repeated reflections to enhance the light intensity of a certain wavelength band and reduce the light intensity of another wavelength band.
  • the microcavity is applied to the front emission organic light emitting diode (OLED)
  • the luminance can improve the luminous efficiency. That is, the light emitted from the organic light emitting layer of the organic light emitting diode is emitted to the outside of the display through the glass substrate without directivity.
  • two layers of highly reflective materials are formed on the both sides of the organic light emitting layer to form a microcavity structure, light resonance occurs and one side Intensified in the direction (front-facing of the display device). As a result, the luminance and luminous efficiency of the organic light emitting diode can be increased.
  • the black film is formed on the front surface of the organic light emitting diode to prevent external light from being reflected by the organic light emitting diode to lower the brightness and contrast ratio.
  • a factor that determines the contrast ratio of a display device is luminance reflectance.
  • the clear contrast ratio is expressed by the following equation (1).
  • the luminance reflectance of the organic light emitting diode should be reduced.
  • a front emission type organic light emitting diode is formed on the back of the organic light emitting layer with a material layer having excellent reflection properties to reflect the light generated from the organic light emitting layer to the front.
  • the external light introduced into the organic light emitting diode is The contrast ratio is increased because it can be prevented from being reflected and emitted back to the front.
  • the organic light emitting diode includes a reflective electrode layer 401, an organic light emitting layer 402, a transparent electrode layer 403, a first metal layer 404, a dielectric layer 405, a second metal layer 406, and a substrate 407. ).
  • the reflective electrode layer 401 and the transparent electrode layer 403 When an electric field is applied between the reflective electrode layer 401 and the transparent electrode layer 403, light is generated in the organic light emitting layer 402, and a part of the generated light is emitted to the front surface without being reflected by the reflective electrode layer 401, and part of the reflection is reflected. Reflected by the electrode layer 401 is emitted to the front.
  • external light is introduced into the inside through the substrate 407 and reflected by the reflective electrode layer 401, the first metal layer 404, and the second metal layer 406.
  • FIG. 5 is a view for explaining the resonance of light caused by the microcavity and the extinction interference of external light by the black film in the organic light emitting diode of the present invention.
  • light generated in the organic light emitting layer 402 is resonated by the reflective electrode layer 401 and the first metal layer 404.
  • the light generated by the organic light emitting layer 402 is reflected by the reflective electrode layer 401 and the first metal layer 404 before being emitted to the front surface, and the light intensity of a specific wavelength band is enhanced and emitted to the front surface.
  • the first metal layer should be formed to have a relatively thin thickness so that the light can pass therethrough, and the reflective electrode layer can transmit the light. It should be formed to a relatively thick thickness.
  • the reflective electrode layer may be made of a metal material such as aluminum or silver having excellent reflection characteristics.
  • the color purity of the organic light emitting diode may be controlled by adjusting the thickness of the transparent electrode layer.
  • the black microcavity of the present invention may be formed of the first metal layer 404, the dielectric layer 405, and the second metal layer 406, and may pass through a substrate made of a transparent material such as glass.
  • One external light is reflected by the first metal layer 404 and the second metal layer 406.
  • the thicknesses of the first electrode layer, the dielectric layer, and the second electrode layer may be adjusted such that external light reflected by the first metal layer 404 and the second metal layer 406 is extinguished and canceled out. As described above with reference to FIG.
  • the physical properties of the layers constituting the black microcavity are controlled.
  • the first metal layer has a higher reflectance than the second metal layer. This is to cause the light generated in the organic light emitting layer to be reflected and resonate between the reflective electrode layer and the first metal layer.
  • the absorbance of the first metal layer is relatively lower than the absorbance of the second metal layer.
  • the first metal layer a metal material having high reflectivity and low absorbance, such as at least one metal selected from the group consisting of Al, Ag, and Au, or an alloy thereof, is preferably used.
  • a metal material having low reflectivity and high absorbance such as at least one metal selected from the group consisting of Cr, Mo, Ti, Co, and Ni or an alloy thereof, is preferably used.
  • the dielectric layer disposed between the first metal layer and the second metal layer changes the phase of external light flowing into the organic light emitting diode to induce extinction interference.
  • the first electrode layer, the dielectric layer, and the second layer of the black microcavity The material and thickness of the electrode layer should be set so that the light reflected from each of the first electrode layer, the dielectric layer, and the second electrode layer causes a destructive interference.
  • Cr chromium
  • SiO 2 silicon oxide
  • Ag 160 nm thick silver
  • Ig 115 nm thick indium tin oxide
  • an 140 nm thick organic light emitting layer And conditions for the organic light emitting diode on which an aluminum layer having a reflectance of 90% or more was formed, and simulations of wavelength versus luminance and external light reflectivity were performed.
  • the simulation was performed under the same conditions as in Example 1-1 except that the thickness of the silver (Ag) layer was set to 18 nm.
  • the simulation was performed under the same conditions as in Example 1-1 except that the thickness of the silver (Ag) layer was set to 20 nm.
  • the simulation was performed under the same conditions as in Example 1-1 except that the thickness of the silver (Ag) layer was set to 22 nm.
  • the simulation was performed under the same conditions as in Example 1-1 except that the thickness of the silver (Ag) layer was set to 24 nm.
  • the simulation was performed under the same conditions as in Example 1-1 except that the thickness of the silver (Ag) layer was set to 26 nm.
  • the simulation was performed under the same conditions as in Example 1-3 except that the thickness of the chromium (Cr) layer was set to 10 nm.
  • the simulation was performed under the same conditions as in Example 1-3 except that the thickness of the chromium (Cr) layer was set to 11 nm.
  • the simulation was performed under the same conditions as in Example 1-3 except that the thickness of the chromium (Cr) layer was set to 13 nm.
  • Example 1-1 Except that 12 nm chromium (Cr) layer, 40 nm thick silicon oxide (SiO 2 ) layer, 160 nm thick silver (Ag) layer, and 115 nm thick indium tin oxide layer were not applied. The simulation was performed under the same conditions as in Example 1-1.
  • Examples 1-1 to 1-4 and Comparative Example 1-1 were as shown in FIG. Referring to FIG. 6A, luminance of the organic light emitting diodes of Examples 1-1 to 1-4 was significantly increased as compared with the organic light emitting diode of Comparative Example 1-1.
  • the numerical values in parentheses shown in the graph of FIG. 6A indicate relative luminance ratios or luminous efficiency ratios. In Examples 1-1 to 1-4, the thinner the thickness of the silver layer, the higher the luminance or the luminous efficiency. This result is because, in Comparative Example 1-1, much of the light generated in the organic light emitting layer is absorbed in the circularly polarized layer.
  • Wavelength to external light reflectivity for Examples 1-2 to Examples 1-6 and Comparative Examples 1-2 were as in FIG. Referring to (b) of FIG. 6, the organic light emitting diodes of Examples 1-2 to 1-6 had significantly lower external light reflectivity than the organic light emitting diode of Comparative Example, and the thicker the silver layer, the more external light reflectivity. Low.
  • the wavelength-to-luminance curves for Examples 1-3, Examples 1-7 to Examples 1-9, and Comparative Example 1-1 were as shown in FIG. Referring to (a) of FIG. 7, the organic light emitting diodes of Examples 1-3 and Examples 1-7 to 1-9 had a significantly higher luminance than the organic light emitting diodes of Comparative Example 1-1.
  • the numerical values in parentheses shown in the graph of FIG. 7A indicate relative luminance ratios or luminous efficiency ratios. In Examples 1-3 and Examples 1-7 to 1-9, the thinner the chromium layer, the higher the luminance or the luminous efficiency. This result is because, in Comparative Example 1-1, much of the light generated in the organic light emitting layer is absorbed in the circularly polarized layer.
  • Wavelength versus external light reflectivity for Examples 1-3, Examples 1-7 to Examples 1-9, and Comparative Examples 1-2 were as shown in FIG. Referring to FIG. 7B, the organic light emitting diodes of Examples 1-3 and Examples 1-7 to 1-9 had a significantly lower external light reflectivity than the organic light emitting diodes of Comparative Examples 1-2. The thicker the chromium layer, the lower the external light reflectivity.
  • the organic light emitting diode of the present invention can be seen that the luminance and luminous efficiency is significantly higher than when the circular polarization layer is applied, and the external light reflectivity is significantly lower than when the circular polarization layer is not applied. .
  • the thickness of the silver or chromium layer is thinner, the luminance increases, and the thickness of the silver or chromium layer tends to decrease the external light reflectivity. Therefore, it is preferable to set the thickness of the silver or chromium layer under the condition that the brightness or contrast ratio is at an appropriate level. .
  • the present invention can be usefully used in the display industry.

Abstract

The present invention relates to an organic light-emitting diode comprising: a reflective electrode layer; an organic light-emitting layer formed on a lower surface of the reflective electrode layer; a transparent electrode layer formed on a lower surface of the organic light-emitting layer; and a black micro-cavity formed on a lower surface of the transparent electrode layer, wherein the black micro-cavity is formed by sequentially stacking a first metal layer, a dielectric layer and a second metal layer on the lower surface of the transparent electrode layer.

Description

블랙 마이크로캐비티를 포함하는 유기발광다이오드Organic Light Emitting Diodes Containing Black Microcavity
본 발명은 유기발광다이오드에 관한 것으로서, 더욱 상세하게는 휘도가 증가되고 명실 명암비가 향상된 유기발광다이오드에 관한 것이다.The present invention relates to an organic light emitting diode, and more particularly, to an organic light emitting diode having increased brightness and improved contrast ratio.
유기발광다이오드는 전계가 가해지면 발광하는 성질을 가진 유기발광물질을 이용한 자발광소자로서 차세대 디스플레이 장치로 연구가 많이 이루어지고 있다. 유기발광다이오드는 양전극과 음전극, 그리고 그 사이에 형성된 유기발광층을 포함한다. 양전극과 음전극 사이에 전압이 인가되면 정공이 양전극으로부터 유기발광층 내로 주입되고, 전자는 음전극으로부터 유기발광층내로 주입된다. 유기발광층 내로 주입된 정공과 전자는 유기발광층에서 결합하여 엑시톤(exiton)을 생성하고, 이러한 엑시톤이 여기상태에서 기저상태로 전이하면서 빛이 방출된다.Organic light emitting diodes are self-light emitting devices using organic light emitting materials that emit light when an electric field is applied. The organic light emitting diode includes a positive electrode and a negative electrode, and an organic light emitting layer formed therebetween. When a voltage is applied between the positive electrode and the negative electrode, holes are injected from the positive electrode into the organic light emitting layer, and electrons are injected from the negative electrode into the organic light emitting layer. Holes and electrons injected into the organic light emitting layer combine in the organic light emitting layer to generate excitons, and light is emitted as the excitons transition from the excited state to the ground state.
전면방출형 유기발광다이오드는 양전극로 빛을 반사시킬 수 있는 물질을 사용하고, 음전극으로 빛을 투과시킬 수 있는 물질을 사용하여 유기발광층에서 발생된 광이 유기발광다이오드의 전면으로 효과적으로 방출되도록 한다. 그러나 양전극을 반사특성이 우수한 물질로 구성하는 경우 명실 명암비가 낮아지는 문제가 발생된다. 즉, 전면으로 유입되는 외부광이 양전극에서 반사되며 명실 명암비를 떨어뜨리게 되는 것이다. 도 1은 종래의 전면방출형 유기발광다이오드에서 명실 명암비가 낮아지는 이유를 설명하기 위한 도면이다. 도 1을 참조하면, 종래의 전면방출형 유기발광다이오드는 반사특성이 우수한 양전극(101), 광투과도가 높은 음전극(103), 양전극과 음전극 사이에 형성된 유기발광층(102) 및 유리기판(104)을 포함한다. 전면방출형 유기발광다이오드의 전면에서는 외부광이 유입되는데, 유입된 외부광은 반사특성이 우수한 물질로 이루어진 양전극(101)에서 반사되어 다시 전면으로 방출된다. 도 2는 반사특성이 우수한 양전극을 포함하는 유기발광다이오드의 외부광 반사특성을 나타낸 것이다. 도 2를 참조하면, 종래의 전면방출형 유기발광다이오드의 경우 가시광선 영역에서 빛의 반사도가 60~70%에 육박함을 알 수 있다. 이렇게 외부로 반사되는 외부광은 오프(off)되어야 할 화소가 일정 수준의 빛을 반사하게 하여 명실 명암비를 떨어뜨리게 만들고, 결과적으로 디스플레이 장치의 성능을 저하시키게 한다. The front emission type organic light emitting diode uses a material that can reflect light to the positive electrode and a material that can transmit light to the negative electrode so that the light generated in the organic light emitting layer is effectively emitted to the front surface of the organic light emitting diode. However, when the positive electrode is made of a material having excellent reflection characteristics, the problem of lowering the contrast ratio occurs. In other words, the external light flowing to the front surface is reflected from the positive electrode, and the contrast ratio is reduced. 1 is a view for explaining the reason why the contrast ratio is lower in the conventional front emission type organic light emitting diode. Referring to FIG. 1, a conventional front emission type organic light emitting diode includes a positive electrode 101 having excellent reflection characteristics, a negative electrode 103 having high light transmittance, an organic light emitting layer 102 and a glass substrate 104 formed between the positive electrode and the negative electrode. It includes. External light is introduced from the front surface of the front emission type organic light emitting diode, and the external light is reflected by the positive electrode 101 made of a material having excellent reflection characteristics and is emitted to the front surface again. 2 illustrates external light reflection characteristics of an organic light emitting diode including a positive electrode having excellent reflection characteristics. Referring to FIG. 2, in the case of the conventional front emission type organic light emitting diode, the reflectivity of light in the visible light region is nearly 60 to 70%. This externally reflected external light causes the pixels to be turned off to reflect a certain level of light, which lowers the contrast ratio and consequently degrades the performance of the display device.
전면방출형 유기발광다이오드에서 명실 명암비를 증가시키기 위한 노력 중 하나는 원형편광기를 이용하는 것이다. 도 3은 원형편광기를 이용한 전면방출형 유기발광다이오드를 설명하기 위한 도면이다. 도 3의 (a)를 참조하면, 유기발광다이오드는 양전극(101), 음전극(103), 유기발광층(102) 및 유리기판(104)을 포함하고, 유리기판(104)의 전면에 원형편광층(105)이 형성되어 있다. 유기발광다이오드의 전면에서 유입되는 외부광은 원형편광층(105)을 통과하며 흡수되므로 외부로 반사되지 않는다. 도 3의 (b)와 (c)를 참조하면, 원형편광층(105)은 보호층(105a, 105c), 선형편광층(105b), 접착층(105d, 105f) 및 1/4 파장층(105e)을 포함한다. 외부광은 선형편광층을 통과하는 과정에서 일정한 방향의 편광만 통과하게 되고 나머지 방향의 편광은 통과하지 못한다. 선형편광층을 통과한 편광은 1/4 파장층을 통과하여 미러에서 반사되는데, 그 과정에서 편광의 방향이 90°로 변화하게 되어 선형편광층을 통과할 수 없게 된다. 이와 같이, 원형편광층은 외부광이 유기발광다이오드에서 반사될 수 없도록 하여 유기발광다이오드의 명실 명암비를 증가시키게 된다. 그러나 이러한 원형편광층을 사용한 유기발광다이오드는 선형편광층의 투과율이 40~45%이므로 유기발광층에서 발생된 빛의 50% 이상이 선형편광층에 흡수되어 휘도가 저하되는 문제점을 가지고, 선형편광층의 두께도 0.2㎜ 정도로 두꺼워서 디스플레이 소자의 전체적인 두께를 증가시키며, 추가적인 공정이 요구되므로 인테그레이트 소자를 제작하기 어려운 문제점을 가지고 있다.One of the efforts to increase the contrast ratio in front emission organic light emitting diodes is the use of circular polarizers. 3 is a view for explaining a front emission type organic light emitting diode using a circular polarizer. Referring to FIG. 3A, the organic light emitting diode includes a positive electrode 101, a negative electrode 103, an organic light emitting layer 102, and a glass substrate 104, and a circular polarization layer on the entire surface of the glass substrate 104. 105 is formed. External light flowing from the front surface of the organic light emitting diode passes through the circular polarization layer 105 and is not reflected to the outside. Referring to FIGS. 3B and 3C, the circularly polarized layer 105 may include protective layers 105a and 105c, linearly polarized layer 105b, adhesive layers 105d and 105f, and quarter-wave layer 105e. ). In the process of passing the linear polarization layer, the external light passes only the polarization in a predetermined direction and does not pass through the polarization in the other direction. The polarized light passing through the linear polarized layer passes through the quarter wavelength layer and is reflected by the mirror. In the process, the direction of the polarized light is changed by 90 ° and thus cannot pass through the linear polarized layer. As such, the circularly polarized layer prevents external light from being reflected from the organic light emitting diode, thereby increasing the brightness and contrast ratio of the organic light emitting diode. However, since the organic light emitting diode using the circular polarizing layer has a transmittance of 40 to 45% of the linear polarizing layer, more than 50% of the light emitted from the organic light emitting layer is absorbed by the linear polarizing layer, and thus the luminance is lowered. Since the thickness of is also about 0.2mm thick to increase the overall thickness of the display device, there is a problem that it is difficult to fabricate the integrated device because an additional process is required.
따라서, 본 발명이 해결하고자 하는 과제는 유기발광다이오드의 휘도를 증가시키는 동시에 명실 명암비를 향상시킬 수 있는 전면방출형 유기발광다이오드를 제공하는 것이다.Accordingly, an object of the present invention is to provide a front emission type organic light emitting diode capable of increasing the brightness of the organic light emitting diode and improving the contrast ratio.
본 발명은 상기 과제를 달성하기 위하여, 반사전극층, 상기 반사전극층 하부면에 형성된 유기발광층, 상기 유기발광층 하부면에 형성된 투명전극층, 및 상기 투명전극층 하부면에 형성된 블랙 마이크로캐비티를 포함하고, 상기 블랙 마이크로캐비티는 상기 투명전극층의 하부면에 제1금속층, 유전층 및 제2금속층이 차례로 적층되어 이루어진 유기발광다이오드를 제공한다.The present invention includes a reflective electrode layer, an organic light emitting layer formed on the lower surface of the reflective electrode layer, a transparent electrode layer formed on the lower surface of the organic light emitting layer, and a black microcavity formed on the lower surface of the transparent electrode layer, the black The microcavity provides an organic light emitting diode in which a first metal layer, a dielectric layer, and a second metal layer are sequentially stacked on a lower surface of the transparent electrode layer.
본 발명의 일 실시예에 의하면, 상기 제1금속층의 반사도는 제2금속층의 반사도보다 높은 것이 바람직하다.According to one embodiment of the invention, the reflectivity of the first metal layer is preferably higher than the reflectivity of the second metal layer.
본 발명의 다른 실시예에 의하면, 상기 제1금속층의 흡광도는 제2금속층의 흡광도보다 낮은 것이 바람직하다.According to another embodiment of the present invention, the absorbance of the first metal layer is preferably lower than the absorbance of the second metal layer.
본 발명의 또 다른 실시예에 의하면, 상기 제1금속층은 Al, Ag 및 Au로 구성되는 군으로부터 선택되는 어느 하나 이상의 금속 또는 이들의 합금이고, 상기 제2금속층은 Cr, Mo, Ti, Co 및 Ni로 구성되는 군으로부터 선택되는 어느 하나 이상의 금속 또는 이들의 합금일 수 있다.According to another embodiment of the present invention, the first metal layer is any one or more metals or alloys thereof selected from the group consisting of Al, Ag and Au, the second metal layer is Cr, Mo, Ti, Co and It may be any one or more metals or alloys thereof selected from the group consisting of Ni.
본 발명의 또 다른 실시예에 의하면, 상기 블랙 마이크로캐비티의 제1전극층, 유전층 및 제2전극층의 두께는 상기 제1전극층, 유전층 및 제2전극층 각각에서 반사된 광이 상쇄간섭이 일어나도록 설정될 수 있다.According to another embodiment of the present invention, the thicknesses of the first electrode layer, the dielectric layer, and the second electrode layer of the black microcavity may be set such that the light reflected from each of the first electrode layer, the dielectric layer, and the second electrode layer is caused to cancel each other. Can be.
본 발명의 또 다른 실시예에 의하면, 상기 투명전극층의 두께는 유기발광층에서 발생된 빛이 반사전극층과 제1금속층 사이에서 공진할 수 있도록 설정될 수 있다.According to another embodiment of the present invention, the thickness of the transparent electrode layer may be set so that light generated in the organic light emitting layer may resonate between the reflective electrode layer and the first metal layer.
본 발명의 또 다른 실시예에 의하면, 상기 반사전극층은 알루미늄 또는 은으로 이루어질 수 있다.According to another embodiment of the present invention, the reflective electrode layer may be made of aluminum or silver.
본 발명의 또 다른 실시예에 의하면, 상기 투명전극층은 인듐 틴 옥사이드로 이루어질 수 있다.According to another embodiment of the present invention, the transparent electrode layer may be made of indium tin oxide.
본 발명의 유기발광다이오드는 유기발광층에서 발광된 광이 반사전극층과 제1금속층 사이에서 공진하여 전면으로 방출되는 광의 세기가 증가하므로 휘도가 증가된다. 또한 전면으로 공급되는 외부광이 블랙 마이크로캐비티에 의하여 상쇄간섭을 일으키며 소멸되므로 명실 명암비가 증가한다. 이와 같이 본 발명에 적용되는 블랙 마이크로 캐비티는 유기발광층에서 발광된 광을 공진시키는 마이크로캐비티 기능과 외부광을 흡수하는 블랙 필름 기능을 동시에 구현하므로, 휘도의 증가와 명실 명암비 향상의 효과를 동시에 달성할 수 있도록 한다.In the organic light emitting diode of the present invention, since the light emitted from the organic light emitting layer resonates between the reflective electrode layer and the first metal layer, the intensity of light emitted to the front surface of the organic light emitting diode increases, thereby increasing the luminance. In addition, since the external light supplied to the front is canceled by the black micro-cavity to cancel the interference, the contrast ratio increases. As described above, the black microcavity applied to the present invention simultaneously implements the microcavity function of resonating the light emitted from the organic light emitting layer and the black film function of absorbing external light, thereby simultaneously achieving the effect of increasing the brightness and improving the contrast ratio. To be able.
도 1은 종래의 전면방출형 유기발광다이오드에서 명실 명암비가 낮아지는 이유를 설명하기 위한 도면이다.1 is a view for explaining the reason why the contrast ratio is lower in the conventional front emission type organic light emitting diode.
도 2는 반사특성이 우수한 양전극을 포함하는 유기발광다이오드의 외부광 반사특성을 나타낸 것이다. 2 illustrates external light reflection characteristics of an organic light emitting diode including a positive electrode having excellent reflection characteristics.
도 3은 원형편광기를 이용한 전면방출형 유기발광다이오드를 설명하기 위한 도면이다. 3 is a view for explaining a front emission type organic light emitting diode using a circular polarizer.
도 4는 본 발명의 유기발광다이오드의 단면을 도시한 것이다. 4 is a cross-sectional view of an organic light emitting diode of the present invention.
도 5는 본 발명의 유기발광다이오드에서 일어나는 마이크로캐비티에 의한 광의 공진과 블랙 필름에 의한 외부광의 소멸간섭을 설명하기 위한 도면이다. 5 is a view for explaining the resonance of light caused by the microcavity and the extinction interference of external light by the black film in the organic light emitting diode of the present invention.
도 6은 실시예 1-1 내지 실시예 1-4 및 비교예 1-1에 대한 파장 대 휘도곡선과, 실시예 1-2 내지 실시예 1-6 및 비교예 1-2에 대한 파장 대 외광반사도 곡선을 나타낸 것이다.6 shows wavelength versus luminance curves for Examples 1-1 to 1-4 and Comparative Example 1-1, and wavelengths versus external light for Examples 1-2 to Examples 1-6 and Comparative Examples 1-2. The reflectance curve is shown.
도 7은 실시예 1-3 및 실시예 1-7 내지 실시예 1-9 및 비교예 1-1에 대한 파장 대 휘도곡선과, 실시예 1-3 및 실시예 1-7 내지 실시예 1-9 및 비교예 1-2에 대한 파장 대 외광반사도 곡선을 나타낸 것이다.7 shows wavelength versus luminance curves for Examples 1-3 and Examples 1-7 to 1-9 and Comparative Example 1-1, and Examples 1-3 and Examples 1-7 to 1- Wavelength versus external light reflectivity curves for 9 and Comparative Examples 1-2 are shown.
이하, 본 발명을 상세하게 설명한다.EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.
본 발명의 유기발광다이오드는 반사전극층, 상기 반사전극층 하부면에 형성된 유기발광층, 상기 유기발광층 하부면에 형성된 투명전극층 및 상기 투명전극층 하부면에 형성된 블랙 마이크로캐비티를 포함하고, 상기 블랙 마이크로캐비티는 상기 투명전극층의 하부면에 제1금속층, 유전층 및 제2금속층이 차례로 적층되어 있는 것을 특징으로 한다.The organic light emitting diode of the present invention includes a reflective electrode layer, an organic light emitting layer formed on the lower surface of the reflective electrode layer, a transparent electrode layer formed on the lower surface of the organic light emitting layer, and a black microcavity formed on the lower surface of the transparent electrode layer, wherein the black microcavity is The first metal layer, the dielectric layer, and the second metal layer are sequentially stacked on the lower surface of the transparent electrode layer.
본 발명의 유기발광다이오드는 상기의 구조적 특징에 의하여 휘도를 증가시킬 수 있는 마이크로캐비티(microcavity)와 명실 명암비(ambient contrast)를 향상시킬 수 있는 블랙 필름(black film) 기능을 동시에 구현할 수 있다.The organic light emitting diode of the present invention can implement a black film function that can improve the microcavity and the contrast contrast which can increase the luminance by the above structural features.
마이크로캐비티는 두 개의 반사층 사이에 광을 가두고 반복되는 반사 작용을 일으켜 특정 파장대의 광 세기를 강화시키고, 다른 파장대의 광 세기를 감소시킨다. 전면방출형 유기발광다이오드(organic light emitting diode, OLED)에 마이크로캐비티를 적용하면 휘도가 발광효율을 향상시킬 수 있다. 즉, 유기발광다이오드의 유기발광층에서 방출된 광은 유리기판을 통하여 디스플레이 외부로 방향성 없이 방출되는데, 유기발광층의 양면에 반사도가 높은 두 가지 물질층을 형성하여 마이크로캐비티 구조를 만들면 광의 공진이 일어나며 한쪽 방향(디스플레이 장치의 전면반향)으로 강화된 광을 방출할 수 있다. 따라서 결과적으로 유기발광다이오드의 휘도와 발광효율을 증가시킬 수 있다.The microcavity traps light between the two reflective layers and causes repeated reflections to enhance the light intensity of a certain wavelength band and reduce the light intensity of another wavelength band. When the microcavity is applied to the front emission organic light emitting diode (OLED), the luminance can improve the luminous efficiency. That is, the light emitted from the organic light emitting layer of the organic light emitting diode is emitted to the outside of the display through the glass substrate without directivity. When two layers of highly reflective materials are formed on the both sides of the organic light emitting layer to form a microcavity structure, light resonance occurs and one side Intensified in the direction (front-facing of the display device). As a result, the luminance and luminous efficiency of the organic light emitting diode can be increased.
블랙 필름은 유기발광다이오드의 전면부에 형성되어 외부광이 유기발광다이오드에서 반사되어 명실 명암비가 저하되는 것을 방지할 수 있게 한다. 일반적으로 디스플레이 장치의 명실 명암비를 결정하는 인자는 휘도 반사율(luminance reflectance)이다. 명실 명암비는 하기의 수학식 1로 표현된다.The black film is formed on the front surface of the organic light emitting diode to prevent external light from being reflected by the organic light emitting diode to lower the brightness and contrast ratio. In general, a factor that determines the contrast ratio of a display device is luminance reflectance. The clear contrast ratio is expressed by the following equation (1).
수학식 1 Equation 1
CR = (Lon + RdLambient)/(Loff + RdLambient)CR = (L on + RdL ambient ) / (L off + RdL ambient )
CR:명실 명암비CR: Real contrast ratio
( Lon: full white 상태의 휘도(L on : brightness of full white
Loff: black 상태의 휘도L off : Luminance in black state
Rd: 휘도 반사율Rd: luminance reflectance
Lambient: 외부광의 휘도 )L ambient : Luminance of external light)
상기의 수학식 1에 따라, 명실명암비를 향상시키기 위해서는 유기발광다이오드의 휘도 반사율을 감소시켜야 한다. 전면방출형 유기발광다이오드는 유기발광층에서 발생된 광을 전면으로 반사시키도록 반사특성이 우수한 물질층을 유기발광층의 후면에 형성하는데, 블랙필름을 이용하면 유기발광다이오드의 내부로 유입된 외부광이 반사되어 다시 전면으로 방출되는 것을 방지할 수 있으므로 명실 명암비가 증가된다.According to Equation 1 above, in order to improve the contrast ratio, the luminance reflectance of the organic light emitting diode should be reduced. A front emission type organic light emitting diode is formed on the back of the organic light emitting layer with a material layer having excellent reflection properties to reflect the light generated from the organic light emitting layer to the front. When using a black film, the external light introduced into the organic light emitting diode is The contrast ratio is increased because it can be prevented from being reflected and emitted back to the front.
도 4는 본 발명의 유기발광다이오드의 단면을 도시한 것이다. 도 4를 참조하면, 유기발광다이오드는 반사전극층(401), 유기발광층(402), 투명전극층(403), 제1금속층(404), 유전층(405), 제2금속층(406) 및 기판(407)을 포함한다. 반사전극층(401)과 투명전극층(403) 사이에 전계가 인가되면 유기발광층(402)에서 광이 발생되고, 발생된 광의 일부는 반사전극층(401)에서 반사되지 않고 전면으로 방출되고, 일부는 반사전극층(401)에서 반사되어 전면으로 방출된다. 또한 외부광은 기판(407)을 통하여 내부로 유입되어 반사전극층(401), 제1금속층(404) 및 제2금속층(406)에서 반사된다.4 is a cross-sectional view of an organic light emitting diode of the present invention. Referring to FIG. 4, the organic light emitting diode includes a reflective electrode layer 401, an organic light emitting layer 402, a transparent electrode layer 403, a first metal layer 404, a dielectric layer 405, a second metal layer 406, and a substrate 407. ). When an electric field is applied between the reflective electrode layer 401 and the transparent electrode layer 403, light is generated in the organic light emitting layer 402, and a part of the generated light is emitted to the front surface without being reflected by the reflective electrode layer 401, and part of the reflection is reflected. Reflected by the electrode layer 401 is emitted to the front. In addition, external light is introduced into the inside through the substrate 407 and reflected by the reflective electrode layer 401, the first metal layer 404, and the second metal layer 406.
도 5는 본 발명의 유기발광다이오드에서 일어나는 마이크로캐비티에 의한 광의 공진과 블랙 필름에 의한 외부광의 소멸간섭을 설명하기 위한 도면이다. 도 5의 (a)를 참조하면, 유기발광층(402)에서 발생된 광은 반사전극층(401)과 제1금속층(404)에 의하여 공진된다. 유기발광층(402)에서 발생된 광은 전면으로 방출되기 전에 반사전극층(401)과 제1금속층(404)에서 반사되며 특정 파장대의 광 세기가 강화되어 전면으로 방출된다. 이때, 유기발광층(402)에서 방출된 광이 결과적으로 유기발광다이오드의 전면부로 방출되게 하기 위하여 제1금속층은 광이 투과할 수 있도록 상대적으로 얇은 두께로 형성되어야 하고, 반사전극층은 광이 투과할 수 없도록 상대적으로 두꺼운 두께로 형성되어야 한다. 반사전극층은 반사특성이 우수한 알루미늄이나 은과 같은 금속물질로 이루어질 수 있다. 본 발명에서는, 투명전극층(403)의 두께를 조절하여 광 세기가 강화되는 광의 파장대를 조절할 수 있다. 즉, 인듐 틴 옥사이드(indium tin oxide)와 같이 일정한 굴절율을 가지는 투명전극층 형성물질의 두께를 조절하면, 공진되는 광의 파장대를 원하는대로 조절할 수 있는 것이다. 또한 이러한 투명전극층의 두께를 조절하여 유기발광다이오드의 색순도를 조절할 수도 있다. 도 5의 (b)를 참조하면, 본 발명의 블랙 마이크로캐비티는 제1금속층(404), 유전층(405) 및 제2금속층(406)으로 이루어질 수 있는데, 유리와 같이 투명한 물질로 이루어진 기판을 통과한 외부광은 제1금속층(404) 및 제2금속층(406)에서 반사된다. 제1전극층, 유전층 및 제2전극층의 두께는 제1금속층(404) 및 제2금속층(406)에서 반사된 외부광이 소멸간섭되어 상쇄되도록 조절할 수 있다. 앞에서 도 4를 참조하여 설명한 바와 같이, 유기발광다이오드의 내부로 유입된 외부광의 대부분은 제1금속층(404) 및 제2금속층(406)에서 반사되며 소멸간섭으로 상쇄되고, 반사전극층(401)까지 공급된 일부 외부광도 다시 제1금속층에 의하여 흡수되어 소멸된다. 따라서, 외부광은 유기발광다이오드에서 거의 반사되지 못하므로 명실 명암비가 향상되는 결과를 가져온다.5 is a view for explaining the resonance of light caused by the microcavity and the extinction interference of external light by the black film in the organic light emitting diode of the present invention. Referring to FIG. 5A, light generated in the organic light emitting layer 402 is resonated by the reflective electrode layer 401 and the first metal layer 404. The light generated by the organic light emitting layer 402 is reflected by the reflective electrode layer 401 and the first metal layer 404 before being emitted to the front surface, and the light intensity of a specific wavelength band is enhanced and emitted to the front surface. In this case, in order for the light emitted from the organic light emitting layer 402 to be emitted to the front part of the organic light emitting diode as a result, the first metal layer should be formed to have a relatively thin thickness so that the light can pass therethrough, and the reflective electrode layer can transmit the light. It should be formed to a relatively thick thickness. The reflective electrode layer may be made of a metal material such as aluminum or silver having excellent reflection characteristics. In the present invention, by adjusting the thickness of the transparent electrode layer 403 it is possible to adjust the wavelength band of the light intensity is enhanced. That is, by adjusting the thickness of the transparent electrode layer forming material having a constant refractive index, such as indium tin oxide, the wavelength band of the resonant light can be adjusted as desired. In addition, the color purity of the organic light emitting diode may be controlled by adjusting the thickness of the transparent electrode layer. Referring to FIG. 5B, the black microcavity of the present invention may be formed of the first metal layer 404, the dielectric layer 405, and the second metal layer 406, and may pass through a substrate made of a transparent material such as glass. One external light is reflected by the first metal layer 404 and the second metal layer 406. The thicknesses of the first electrode layer, the dielectric layer, and the second electrode layer may be adjusted such that external light reflected by the first metal layer 404 and the second metal layer 406 is extinguished and canceled out. As described above with reference to FIG. 4, most of the external light introduced into the organic light emitting diode is reflected by the first metal layer 404 and the second metal layer 406, and canceled by extinction interference, and up to the reflective electrode layer 401. Some supplied external light is also absorbed by the first metal layer and then disappears. Therefore, since the external light is hardly reflected by the organic light emitting diode, the brightness and contrast ratio is improved.
본 발명의 유기발광다이오드에 적용되는 블랙 마이크로캐비티가 마이크로캐비티와 블랙 필름의 기능을 동시에 수행하기 위해서는 블랙 마이크로캐비티를 구성하는 각 층의 물성이 제어되는 것이 바람직하다. 먼저, 마이크로캐비티 기능이 확보되기 위하여 제1금속층은 제2금속층에 비하여 반사도가 높은 것이 유리하다. 이는 유기발광층에서 발생된 광이 반사전극층과 제1금속층 사이에서 반사되며 공진되게 하기 위함이다. 다음으로, 블랙 필름의 기능을 위한 제1금속층과 제2금속층의 물성을 살펴보면, 제1금속층의 흡광도가 제2금속층의 흡광도보다 상대적으로 낮은 것이 유리하다. 이는 유기발광다이오드의 내부에서 반사된 외부광을 제2금속층에서 효과적으로 흡수하기 위함이고, 유기발광층에서 발생된 광이 제1금속층을 효과적으로 투과하여야 하는 것과도 관련된다. 상기와 같은 특성을 고려하여 제1금속층으로는 Al, Ag 및 Au로 구성되는 군으로부터 선택되는 어느 하나 이상의 금속 또는 이들의 합금과 같이 높은 반사도 및 낮은 흡광도를 가지는 금속물질이 사용되는 것이 바람직하고, 제2금속층으로는 Cr, Mo, Ti, Co 및 Ni로 구성되는 군으로부터 선택되는 어느 하나 이상의 금속 또는 이들의 합금과 같은 낮은 반사도 및 높은 흡광도를 가지는 금속물질이 사용되는 것이 바람직하다. 제1금속층과 제2금속층 사이에 게재되는 유전층은 유기발광다이오드로 유입되는 외부광의 상(phase)을 변화시켜 소멸간섭을 유도하는 기능을 하게 되는데, 블랙 마이크로캐비티의 제1전극층, 유전층 및 제2전극층의 물질과 두께는 제1전극층, 유전층 및 제2전극층 각각에서 반사된 광이 상쇄간섭이 일어나도록 설정되어야 한다.In order for the black microcavity applied to the organic light emitting diode of the present invention to simultaneously perform the functions of the microcavity and the black film, the physical properties of the layers constituting the black microcavity are controlled. First, in order to secure the microcavity function, it is advantageous that the first metal layer has a higher reflectance than the second metal layer. This is to cause the light generated in the organic light emitting layer to be reflected and resonate between the reflective electrode layer and the first metal layer. Next, looking at the physical properties of the first metal layer and the second metal layer for the function of the black film, it is advantageous that the absorbance of the first metal layer is relatively lower than the absorbance of the second metal layer. This is to effectively absorb the external light reflected from the inside of the organic light emitting diode in the second metal layer, and also relates to the light generated in the organic light emitting layer must effectively transmit the first metal layer. In consideration of the above characteristics, as the first metal layer, a metal material having high reflectivity and low absorbance, such as at least one metal selected from the group consisting of Al, Ag, and Au, or an alloy thereof, is preferably used. As the second metal layer, a metal material having low reflectivity and high absorbance, such as at least one metal selected from the group consisting of Cr, Mo, Ti, Co, and Ni or an alloy thereof, is preferably used. The dielectric layer disposed between the first metal layer and the second metal layer changes the phase of external light flowing into the organic light emitting diode to induce extinction interference. The first electrode layer, the dielectric layer, and the second layer of the black microcavity The material and thickness of the electrode layer should be set so that the light reflected from each of the first electrode layer, the dielectric layer, and the second electrode layer causes a destructive interference.
이하, 바람직한 실시예를 들어 본 발명을 더욱 상세하게 설명한다. 그러나 이들 실시예는 본 발명을 보다 구체적으로 설명하기 위한 것으로, 본 발명의 범위가 이에 의하여 제한되지 않는다는 것은 당업계의 통상의 지식을 가진 자에게 자명할 것이다. Hereinafter, the present invention will be described in more detail with reference to preferred examples. However, these examples are intended to illustrate the present invention in more detail, it will be apparent to those skilled in the art that the scope of the present invention is not limited thereby.
실시예 1-1Example 1-1
유리기판 위에 두께 12nm의 크롬(Cr)층, 두께 40nm의 산화실리콘(SiO2)층, 두께 160nm의 은(Ag)층, 두께 115nm의 인듐 틴 옥사이드(indium tin oxide)층, 두께 140nm의 유기발광층 및 반사도 90% 이상의 알루미늄층이 형성된 유기발광다이오드에 대한 조건을 설정하고 파장 대 휘도 및 외광반사도에 대한 시뮬레이션을 실행하였다.A 12 nm thick chromium (Cr) layer, a 40 nm thick silicon oxide (SiO 2 ) layer, a 160 nm thick silver (Ag) layer, a 115 nm thick indium tin oxide layer, and an 140 nm thick organic light emitting layer And conditions for the organic light emitting diode on which an aluminum layer having a reflectance of 90% or more was formed, and simulations of wavelength versus luminance and external light reflectivity were performed.
실시예 1-2Example 1-2
은(Ag)층의 두께를 18nm로 설정한 것을 제외하고는 실시예 1-1과 동일한 조건에서 시뮬레이션을 실행하였다.The simulation was performed under the same conditions as in Example 1-1 except that the thickness of the silver (Ag) layer was set to 18 nm.
실시예 1-3Example 1-3
은(Ag)층의 두께를 20nm로 설정한 것을 제외하고는 실시예 1-1과 동일한 조건에서 시뮬레이션을 실행하였다.The simulation was performed under the same conditions as in Example 1-1 except that the thickness of the silver (Ag) layer was set to 20 nm.
실시예 1-4Example 1-4
은(Ag)층의 두께를 22nm로 설정한 것을 제외하고는 실시예 1-1과 동일한 조건에서 시뮬레이션을 실행하였다.The simulation was performed under the same conditions as in Example 1-1 except that the thickness of the silver (Ag) layer was set to 22 nm.
실시예 1-5Example 1-5
은(Ag)층의 두께를 24nm로 설정한 것을 제외하고는 실시예 1-1과 동일한 조건에서 시뮬레이션을 실행하였다.The simulation was performed under the same conditions as in Example 1-1 except that the thickness of the silver (Ag) layer was set to 24 nm.
실시예 1-6Example 1-6
은(Ag)층의 두께를 26nm로 설정한 것을 제외하고는 실시예 1-1과 동일한 조건에서 시뮬레이션을 실행하였다.The simulation was performed under the same conditions as in Example 1-1 except that the thickness of the silver (Ag) layer was set to 26 nm.
실시예 1-7Example 1-7
크롬(Cr)층의 두께를 10nm로 설정한 것을 제외하고는 실시예 1-3과 동일한 조건에서 시뮬레이션을 실행하였다.The simulation was performed under the same conditions as in Example 1-3 except that the thickness of the chromium (Cr) layer was set to 10 nm.
실시예 1-8Example 1-8
크롬(Cr)층의 두께를 11nm로 설정한 것을 제외하고는 실시예 1-3과 동일한 조건에서 시뮬레이션을 실행하였다.The simulation was performed under the same conditions as in Example 1-3 except that the thickness of the chromium (Cr) layer was set to 11 nm.
실시예 1-9Example 1-9
크롬(Cr)층의 두께를 13nm로 설정한 것을 제외하고는 실시예 1-3과 동일한 조건에서 시뮬레이션을 실행하였다.The simulation was performed under the same conditions as in Example 1-3 except that the thickness of the chromium (Cr) layer was set to 13 nm.
비교예1-1Comparative Example 1-1
두께 12nm의 크롬(Cr)층, 두께 40nm의 산화실리콘(SiO2)층, 두께 160nm의 은(Ag)층 및 두께 115nm의 인듐 틴 옥사이드(indium tin oxide)층 대신에 원형편광층을 적용한 것을 제외하고는 실시예 1-1과 동일한 조건에서 시뮬레이션을 실행하였다.Except for applying the circularly polarized light layer instead of the chromium (Cr) layer having a thickness of 12 nm, the silicon oxide (SiO 2 ) layer having a thickness of 40 nm, the silver (Ag) layer having a thickness of 160 nm, and the indium tin oxide layer having a thickness of 115 nm. Then, the simulation was performed under the same conditions as in Example 1-1.
비교예1-2Comparative Example 1-2
두께 12nm의 크롬(Cr)층, 두께 40nm의 산화실리콘(SiO2)층, 두께 160nm의 은(Ag)층 및 두께 115nm의 인듐 틴 옥사이드(indium tin oxide)층을 적용하지 않은 것을 제외하고는 실시예 1-1과 동일한 조건에서 시뮬레이션을 실행하였다.Except that 12 nm chromium (Cr) layer, 40 nm thick silicon oxide (SiO 2 ) layer, 160 nm thick silver (Ag) layer, and 115 nm thick indium tin oxide layer were not applied. The simulation was performed under the same conditions as in Example 1-1.
평가예 1Evaluation example 1
실시예 1-1 내지 실시예 1-4 및 비교예 1-1에 대한 파장 대 휘도곡선은 도 6의 (a)와 같았다. 도 6의 (a)를 참조하면, 실시예 1-1 내지 실시예 1-4의 유기발광다이오드는 비교예 1-1의 유기발광다이오드에 비하여 휘도가 현저히 상승하였다. 도 6의 (a) 그래프 내부에 표시된 괄호 안의 수치는 상대적인 휘도비 또는 발광효율비를 나타낸다. 실시예 1-1 내지 실시예 1-4에서는 은층의 두께가 얇을수록 휘도 또는 발광효율이 높았다. 이러한 결과는, 비교예 1-1의 경우는 유기발광층에서 발생된 광의 많은 부분이 원형편광층에서 흡수되기 때문이다.The wavelength-to-luminance curves for Examples 1-1 to 1-4 and Comparative Example 1-1 were as shown in FIG. Referring to FIG. 6A, luminance of the organic light emitting diodes of Examples 1-1 to 1-4 was significantly increased as compared with the organic light emitting diode of Comparative Example 1-1. The numerical values in parentheses shown in the graph of FIG. 6A indicate relative luminance ratios or luminous efficiency ratios. In Examples 1-1 to 1-4, the thinner the thickness of the silver layer, the higher the luminance or the luminous efficiency. This result is because, in Comparative Example 1-1, much of the light generated in the organic light emitting layer is absorbed in the circularly polarized layer.
평가예 2Evaluation example 2
실시예 1-2 내지 실시예 1-6 및 비교예 1-2에 대한 파장 대 외광반사도는 도 6의 (b)와 같았다. 도 6의 (b)를 참조하면, 실시예 1-2 내지 실시예 1-6의 유기발광다이오드는 비교예의 유기발광다이오드에 비하여 외광반사도가 현저히 낮았으며, 은층의 두께가 두꺼울수록 외광반사도가 더 낮았다. Wavelength to external light reflectivity for Examples 1-2 to Examples 1-6 and Comparative Examples 1-2 were as in FIG. Referring to (b) of FIG. 6, the organic light emitting diodes of Examples 1-2 to 1-6 had significantly lower external light reflectivity than the organic light emitting diode of Comparative Example, and the thicker the silver layer, the more external light reflectivity. Low.
평가예 3Evaluation Example 3
실시예 1-3 및 실시예 1-7 내지 실시예 1-9 및 비교예 1-1에 대한 파장 대 휘도곡선은 도 7의 (a)와 같았다. 도 7의 (a)를 참조하면, 실시예 1-3 및 실시예 1-7 내지 실시예 1-9의 유기발광다이오드는 비교예 1-1의 유기발광다이오드에 비하여 휘도가 현저히 상승하였다. 도 7의 (a) 그래프 내부에 표시된 괄호 안의 수치는 상대적인 휘도비 또는 발광효율비를 나타낸다. 실시예 1-3 및 실시예 1-7 내지 실시예 1-9에서는 크롬층의 두께가 얇을수록 휘도 또는 발광효율이 높았다. 이러한 결과는, 비교예 1-1의 경우는 유기발광층에서 발생된 광의 많은 부분이 원형편광층에서 흡수되기 때문이다.The wavelength-to-luminance curves for Examples 1-3, Examples 1-7 to Examples 1-9, and Comparative Example 1-1 were as shown in FIG. Referring to (a) of FIG. 7, the organic light emitting diodes of Examples 1-3 and Examples 1-7 to 1-9 had a significantly higher luminance than the organic light emitting diodes of Comparative Example 1-1. The numerical values in parentheses shown in the graph of FIG. 7A indicate relative luminance ratios or luminous efficiency ratios. In Examples 1-3 and Examples 1-7 to 1-9, the thinner the chromium layer, the higher the luminance or the luminous efficiency. This result is because, in Comparative Example 1-1, much of the light generated in the organic light emitting layer is absorbed in the circularly polarized layer.
평가예 4Evaluation example 4
실시예 1-3 및 실시예 1-7 내지 실시예 1-9 및 비교예 1-2에 대한 파장 대 외광반사도는 도 7의 (b)와 같았다. 도 7의 (b)를 참조하면, 실시예 1-3 및 실시예 1-7 내지 실시예 1-9의 유기발광다이오드는 비교예 1-2의 유기발광다이오드에 비하여 외광반사도가 현저히 낮았으며, 크롬층의 두께가 두꺼울수록 외광반사도가 더 낮았다. Wavelength versus external light reflectivity for Examples 1-3, Examples 1-7 to Examples 1-9, and Comparative Examples 1-2 were as shown in FIG. Referring to FIG. 7B, the organic light emitting diodes of Examples 1-3 and Examples 1-7 to 1-9 had a significantly lower external light reflectivity than the organic light emitting diodes of Comparative Examples 1-2. The thicker the chromium layer, the lower the external light reflectivity.
상기와 같은 시뮬레이션 결과를 검토하면, 본 발명의 유기발광다이오드는 원형편광층을 적용한 경우보다 휘도 및 발광효율이 현저히 높고, 원형편광층을 적용하지 않은 경우에 비하여 외광반사도가 현저히 낮음을 알 수 있다. 은층이나 크롬층의 두께가 얇을수록 휘도가 증가하고, 두꺼울수록 외광반사도가 낮아지는 경향을 보이고 있으므로, 휘도 또는 명실 명암비가 적절한 수준이 되는 조건에서 은층이나 크롬층의 두께를 설정하는 것이 바람직할 것이다.Examining the simulation results as described above, the organic light emitting diode of the present invention can be seen that the luminance and luminous efficiency is significantly higher than when the circular polarization layer is applied, and the external light reflectivity is significantly lower than when the circular polarization layer is not applied. . As the thickness of the silver or chromium layer is thinner, the luminance increases, and the thickness of the silver or chromium layer tends to decrease the external light reflectivity. Therefore, it is preferable to set the thickness of the silver or chromium layer under the condition that the brightness or contrast ratio is at an appropriate level. .
본 발명은 디스플레이 산업에서 유용하게 활용될 수 있다.The present invention can be usefully used in the display industry.

Claims (8)

  1. 반사전극층;Reflective electrode layer;
    상기 반사전극층 하부면에 형성된 유기발광층;An organic light emitting layer formed on a lower surface of the reflective electrode layer;
    상기 유기발광층 하부면에 형성된 투명전극층; 및A transparent electrode layer formed on a lower surface of the organic light emitting layer; And
    상기 투명전극층 하부면에 형성된 블랙 마이크로캐비티를 포함하고,It includes a black micro cavity formed on the lower surface of the transparent electrode layer,
    상기 블랙 마이크로캐비티는 상기 투명전극층의 하부면에 제1금속층, 유전층 및 제2금속층이 차례로 적층되어 이루어진 유기발광다이오드.The black microcavity is an organic light emitting diode formed by sequentially stacking a first metal layer, a dielectric layer, and a second metal layer on a lower surface of the transparent electrode layer.
  2. 제1항에 있어서,The method of claim 1,
    상기 제1금속층의 반사도는 제2금속층의 반사도보다 높은 것을 특징으로 하는 유기발광다이오드.And the reflectivity of the first metal layer is higher than that of the second metal layer.
  3. 제1항에 있어서,The method of claim 1,
    상기 제1금속층의 흡광도는 제2금속층의 흡광도보다 낮은 것을 특징으로 하는 유기발광다이오드.The absorbance of the first metal layer is an organic light emitting diode, characterized in that lower than the absorbance of the second metal layer.
  4. 제1항에 있어서,The method of claim 1,
    상기 제1금속층은 Al, Ag 및 Au로 구성되는 군으로부터 선택되는 어느 하나 이상의 금속 또는 이들의 합금이고, 상기 제2금속층은 Cr, Mo, Ti, Co 및 Ni로 구성되는 군으로부터 선택되는 어느 하나 이상의 금속 또는 이들의 합금인 것을 특징으로 하는 유기발광다이오드.The first metal layer is any one or more metals or alloys thereof selected from the group consisting of Al, Ag and Au, and the second metal layer is any one selected from the group consisting of Cr, Mo, Ti, Co and Ni. An organic light emitting diode comprising the above metals or alloys thereof.
  5. 제1항에 있어서,The method of claim 1,
    상기 블랙 마이크로캐비티의 제1전극층, 유전층 및 제2전극층의 두께는 상기 제1전극층, 유전층 및 제2전극층 각각에서 반사된 광이 상쇄간섭이 일어나도록 설정된 것을 특징으로 하는 유기발광다이오드.The thickness of the first electrode layer, the dielectric layer and the second electrode layer of the black micro-cavity is characterized in that the light reflected from each of the first electrode layer, the dielectric layer and the second electrode layer is set to cancel the interference.
  6. 제1항에 있어서,The method of claim 1,
    상기 투명전극층의 두께는 유기발광층에서 발생된 빛이 반사전극층과 제1금속층 사이에서 공진할 수 있도록 설정된 것을 특징으로 하는 유기발광다이오드.The thickness of the transparent electrode layer is an organic light emitting diode, characterized in that the light generated from the organic light emitting layer is set so as to resonate between the reflective electrode layer and the first metal layer.
  7. 제1항에 있어서,The method of claim 1,
    상기 반사전극층은 알루미늄 또는 은으로 이루어진 것을 특징으로 하는 유기발광다이오드.The reflective electrode layer is an organic light emitting diode, characterized in that made of aluminum or silver.
  8. 제1항에 있어서,The method of claim 1,
    상기 투명전극층은 인듐 틴 옥사이드로 이루어진 것을 특징으로 하는 유기발광다이오드.The transparent electrode layer is an organic light emitting diode, characterized in that made of indium tin oxide.
PCT/KR2010/005040 2009-11-23 2010-07-30 Organic light-emitting diode comprising a black micro-cavity WO2011062351A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR10-2009-0113293 2009-11-23
KR1020090113293A KR101114253B1 (en) 2009-11-23 2009-11-23 Organic light emitting diode with black microcavity

Publications (1)

Publication Number Publication Date
WO2011062351A1 true WO2011062351A1 (en) 2011-05-26

Family

ID=44059798

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2010/005040 WO2011062351A1 (en) 2009-11-23 2010-07-30 Organic light-emitting diode comprising a black micro-cavity

Country Status (2)

Country Link
KR (1) KR101114253B1 (en)
WO (1) WO2011062351A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107195797A (en) * 2017-06-28 2017-09-22 京东方科技集团股份有限公司 A kind of display base plate and display device

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101271413B1 (en) * 2011-12-09 2013-06-05 한국과학기술원 High contrast organic light emitting device and display apparatus comprising the same
KR101602422B1 (en) * 2012-06-21 2016-03-10 코닝정밀소재 주식회사 Black matrix coated substrate and oled display device comprising the same
KR20150051479A (en) 2013-11-04 2015-05-13 삼성디스플레이 주식회사 Display apparatus and a method for preparing the same
KR102584304B1 (en) 2016-04-26 2023-10-04 삼성디스플레이 주식회사 Color conversion panel and display device comprising the same
WO2022050454A1 (en) * 2020-09-04 2022-03-10 엘지전자 주식회사 Display apparatus

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20060059721A (en) * 2004-11-29 2006-06-02 삼성에스디아이 주식회사 Flat panel display apparatus and fabricating method of the same
JP2006210204A (en) * 2005-01-31 2006-08-10 Dainippon Printing Co Ltd Substrate for rear face with improved reflectivity and display using it
JP2007103303A (en) * 2005-10-07 2007-04-19 Toshiba Matsushita Display Technology Co Ltd Organic el display device
KR20090038637A (en) * 2007-10-16 2009-04-21 삼성전자주식회사 White organic light emitting device and color display apparatus employing the same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20060059721A (en) * 2004-11-29 2006-06-02 삼성에스디아이 주식회사 Flat panel display apparatus and fabricating method of the same
JP2006210204A (en) * 2005-01-31 2006-08-10 Dainippon Printing Co Ltd Substrate for rear face with improved reflectivity and display using it
JP2007103303A (en) * 2005-10-07 2007-04-19 Toshiba Matsushita Display Technology Co Ltd Organic el display device
KR20090038637A (en) * 2007-10-16 2009-04-21 삼성전자주식회사 White organic light emitting device and color display apparatus employing the same

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107195797A (en) * 2017-06-28 2017-09-22 京东方科技集团股份有限公司 A kind of display base plate and display device
CN107195797B (en) * 2017-06-28 2019-11-01 京东方科技集团股份有限公司 A kind of display base plate and display device
US11251409B2 (en) 2017-06-28 2022-02-15 Chengdu Boe Optoelectronics Technology Co., Ltd. Display substrate and display device

Also Published As

Publication number Publication date
KR20110056819A (en) 2011-05-31
KR101114253B1 (en) 2012-03-05

Similar Documents

Publication Publication Date Title
KR101431107B1 (en) Display device and electronic apparatus having the same
WO2011062351A1 (en) Organic light-emitting diode comprising a black micro-cavity
US10368418B2 (en) Display unit, method of manufacturing the same, and electronic apparatus
TWI617023B (en) Display device and optical film
KR100855659B1 (en) Display unit
US10930889B2 (en) Light-emitting device, display apparatus, and illumination apparatus
WO2011055896A1 (en) Black organic light-emitting diode device
US10446798B2 (en) Top-emitting WOLED display device
US10497758B2 (en) Display substrate and manufacture method thereof, display panel
TWI231726B (en) Electroluminescence display
US8033675B2 (en) Light emitting device and electronic device
KR20030081100A (en) Organic luminescence device and organic luminescence device package
US20110068361A1 (en) High performance light-emitting devices
JP7356545B2 (en) display device
JP4454354B2 (en) Luminescent display device
KR20090037274A (en) White organic light emitting device and color display apparatus employing the same
JP2007053115A (en) Display device
WO2007004106A1 (en) Light-emitting device
CN110890476A (en) Display panel and display device
KR20200058154A (en) Electro-luminescence display apparatus
KR100326464B1 (en) Electroluminescent display device
TWI747382B (en) Light emitting device
CN108598124A (en) Display device
JP7475180B2 (en) Light-emitting device, display device, imaging device, electronic device, lighting device, and mobile object
CN117897017A (en) Display module and display device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10831718

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 10831718

Country of ref document: EP

Kind code of ref document: A1