White-light organic electroluminescent device and preparation method thereof

Abstract

The invention discloses a white-light organic electroluminescent device, which comprises a substrate, an anode layer, a cathode layer and an organic functional layer arranged between the anode layer and the cathode layer, wherein the organic functional layer comprises a luminous layer; a blue phosphorescence dye is doped in the wide band gap main body matrix with hole transmission property, and a complementary phosphorescence dye is doped in the main body matrix with electron transmission and hole blocking properties, so that the hole and electrode resonance is transmitted onto the blue phosphorescence dye molecules to directly form excitonic composite luminescence; according to the hole blocking property of the complementary phosphorescence dye main body matrix, the complementary phosphorescence dye is prevented from trapping excessive hole current carriers, the luminous strength of the blue light dye is enhanced, and annihilation of excitons and polarons in the complementary phosphorescence luminous layer is inhibited at the same time, so that uniform and stable white light emission is obtained; and relatively weak blue light emission and even total quenching in the conventional white light device are solved, and the obtained phosphorescence white light device has simple structure, is easily controlled and efficient.

Description

Technical field [0001] The present invention relates to the technical field of organic electroluminescence devices, in particular to white light organic electroluminescence devices and a preparation method thereof. Background technique [0002] Compared with monochromatic devices, white light needs to cover the entire visible light region due to the width of its emission spectrum, so the device structure is more complicated. Therefore, the research of white organic electroluminescent devices (WOLED) started later than monochromatic light devices. But since WOLED was reported by J. Kido et al. (Appl. Phys.lett., 1994, 64, 815) in 1994, WOLED has aroused widespread interest. At present, as the most widely used white organic electroluminescent device with the most optimistic development prospects, it has begun to attract the attention of the industrial and scientific circles all over the world. As energy is the focus of competition among countries in the 21st century, energy conser...

AI Technical Summary

Problems solved by technology

In the multi-emitting layer structure, due to the strong carrier capture ability of long-wavelength dyes compared with blue-light dyes, the recombination region is mainly concentrated in the light-emitting layer of long-wavelength dyes, and the energy transfer between the two can be quenched. Emission of blue light, so there is only very weak or even no blue light emission in the spectrum, and finally it is difficult to obtain white light

Therefore, Forrest et al. (Nature 2006, 440, 908) obtained white light by inserting an electron or hole blocking layer between the light-emitting layers to avoid energy transfer between the light-emitting layers, but the use of materials for the exciton blocking layer is not conducive to Transport of carriers, resulting in higher turn-on voltage of the device and lower power efficiency

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