Optical transition layer material, optical substrate/packaging layer, OLED (Organic Light Emitting Diode) and manufacturing methods thereof

Abstract

The invention relates to an organic electroluminescent technology and discloses a method for improving the luminous efficiency. The method can be applied to various types of OLED (Organic Light Emitting Diode) devices of bottom emission, top emission, transparency and the like. The invention provides an optical transition layer material, an optical substrate (packaging layer), an OLED, and manufacturing methods thereof. If the OLED is the bottom-emission OLED, an optical transition layer is manufactured on the substrate; if the OLED is the top-emission OLED, the optical transition layer is manufactured on the packaging layer; and if the OLED is the transparent OLED, the optical transition layer can be independently or simultaneously manufactured on the substrate or the packaging layer. An organic material main body with high light transmittance and moderate refractive index and an inorganic nano grain with the high light transmittance and low absorption rate are selected; the inorganic nano grain is used as a scattering medium to be scattered into the organic material main body to prepare the optical transition layer material; and the optical transition layer material is used for preparing an optical transition layer on the substrate (packaging layer) including glass and the like, so that the full-reflection loss of emergent light is effectively reduced and the luminous efficiency of the OLED is improved by 20-50%.

Description

technical field [0001] The invention relates to organic electroluminescence technology, in particular to an optical transition layer material capable of improving light extraction efficiency, an optical substrate (encapsulation layer), OLED and their respective manufacturing methods. Background technique [0002] Organic electroluminescence (OLED, Organic Light-Emitting Diode) is a phenomenon in which organic materials are excited by electrical energy to emit light. An OLED is a "sandwich" structure consisting of an anode, a cathode and a layer of organic material between them. The organic material layer generally includes a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. By applying an appropriate voltage between the electrodes, OLED devices can emit light. [0003] see figure 1 , represents the OLED structure and its light propagation path, wherein: the inner surface of the glass substra...

AI Technical Summary

Problems solved by technology

This situation will bring the following problems: (1) The low light extraction efficiency forces people to use high-grade luminescent materials or increase the input current to meet the requirements of high brightness, which increases the cost of materials and shortens the use of devices life; (2) The energy that cannot be taken out (nearly 80%) will be converted into heat, which will greatly increase the temperature of the organic functional layer, which will not only deteriorate the stability and photoelectric parameter performance of the OLED, but also shorten the life of the OLED; (3) In order to To eliminate the impact of generated heat on OLED performance and lifespan, heat dissipation design must be carried out, which increases production costs

Surface roughening will seriously reduce the light transmittance of glass, so that the effect of improving light extraction efficiency is not obvious; microlenses can greatly improve light extraction efficiency, but the manufacturing process is complicated; high light transmittance, short-wavelength irradiation, and low temperature Short-time cured organic materials (refractive index between glass and air) make transition layer, which will not affect the exit of light, but currently the organic materials that can be applied here have a refractive index between 1.4-1.55, and there is no suitable condition organic materials (refractive index 1.25-1.35)

[0006] Some studies have pointed out that making a scattering medium layer on the glass surface can increase the light extraction efficiency by 40%, but there is no public literature on how to make the scattering medium layer and apply it to OLED products. conduct in-depth research on this

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