Organic electroluminescent device and display device

Abstract

The invention provides an organic electroluminescent device and a display device. The organic electroluminescent device comprises a substrate, an opaque electrode, a luminescent layer and a transparent electrode, wherein the opaque electrode, the luminescent layer and the transparent electrode are arranged above the substrate, the luminescent layer is arranged between the opaque electrode and the transparent electrode, a diffusion layer is also arranged between the luminescent layer and the opaque electrode, and the light, facing one side of the diffusion layer, emitted from the luminescent layer can be fully reflected by the diffusion layer. The organic electroluminescent device has the advantage that by arranging the diffusion layer between the luminescent layer and the opaque electrode, the external quatum efficiency is improved, and the internal quatum efficiency is also improved, so the efficiency is improved. The display device of the organic electroluminescent device can improve the efficiency and display effect.

Description

technical field [0001] The present invention relates to the field of display technology, in particular to an organic electroluminescent device and a display device. Background technique [0002] Organic electroluminescent devices (OLEDs) have the advantages of wide viewing angle, fast response, and wide color gamut as display devices; as lighting devices, they have the characteristics of planarization, no mercury pollution, and high efficiency. They are the development of the next generation of display and lighting. trend. [0003] The structure of the current organic electroluminescent device is basically that there are multiple organic layers sandwiched between two layers of metal. The organic layer includes a light-emitting layer, and the two layers of metal are the anode and cathode of the device. Under the action of external voltage, electrons and holes are injected into the organic layer from the cathode direction and the anode direction respectively and transported, ...

AI Technical Summary

Problems solved by technology

[0004] There are two main aspects of energy loss in organic electroluminescent devices: the first aspect of loss is that when injected carriers (referring to electrons and holes) are coupled to emit light in the light-emitting layer, not all of the injected energy is converted into For photons, a part of the excitonic energy is lost through non-radiative transition processes such as lattice vibration and deep-level impurity transitions, which reduces the internal quantum efficiency of organic electroluminescent devices

The second loss is the total emission at the interface between the metal layer (anode or cathode) / glass substrate, glass substrate / air, the waveguide mode between the metal / organic layer interface and the metal layer (anode or cathode) The nearby surface plasmon loss, etc., lead to the light emitted from the light-emitting layer after experiencing the above-mentioned multi-layer structure, only about 20% can pass through the device and enter the air to be seen by us, which reduces the efficiency of the organic electroluminescent device. External quantum efficiency, external quantum efficiency is the efficiency at which light is extracted from the device, also known as light efficiency

However, direct introduction of metal nanoparticles into the light-emitting layer or other layers of organic electroluminescent devices can lead to other negative effects, as pointed out in Chem. Mater. Nanoparticles can also cause strong hole blocking effects and high operating voltages, deteriorating device performance

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