Combined luminescent material and application thereof

Abstract

The invention discloses a combined luminescent material and application thereof, and belongs to the technical field of luminescent materials. The combined luminescent material comprises a host material and a guest material, the transition dipole moment horizontal orientation degree of the host material is greater than 80%; and the guest material is at least one of a thermally activated delayed fluorescent material and a conventional fluorescent material. The host material with the transition dipole moment horizontal orientation degree larger than 80% and the light-emitting guest material are combined, the host material can sensitize the guest material, then the transition dipole moment horizontal orientation degree of the guest material is improved, and after the material is used for a light-emitting diode, the light extraction efficiency and the external quantum efficiency of the diode can be improved.

Description

Technical field [0001] The present invention belongs to the technical field of luminescent materials, and more particularly to a combined luminescent material and its application thereof. Background technique [0002] Organic Light Emitting Diodes (OLED) has high color contrast, fast response speed, low power consumption, no blue-ray harm, and flexible display, has been applied in solid-state lighting and display, and has good application prospects. [0003] The existing organic luminescent materials have: In 1998, Professor, Princeton University, developed phosphorescent materials containing heavy metal atoms, as well as professor of Adachi, Japan, Japan, etc., etc., etc., has developed heat activation delays with smaller single three-line energy gap. Fluorescent material. These materials can effectively utilize the three-line excitons to achieve luminescence, in theory, 100% internal quantum efficiency can be realized, that is, to a large extent, the efficiency of organic light...

AI Technical Summary

Problems solved by technology

However, in OLEDs, due to the large gap between the refractive index of the organic layer (n≈1.7-2.0) and the glass substrate (n≈1.5) and air (n≈1.0), when the carrier When recombining in the light-emitting layer and radiating light outward, if the light is incident on the substrate at an angle greater than the critical angle, due to the waveguide mode, the light will be fully emitted at the interface between the glass substrate and the organic layer, and thus be confined in the organic layer. ; Similarly, if the light is emitted from the substrate to the air at an angle greater than the critical angle, due to the substrate mode, the light will be totally reflected at the interface between the glass substrate and the air, causing the light to be confined in the glass substrate; The extraction efficiency is low, which hinders the improvement of the theoretical efficiency of the device

[0004] Therefore, the external quantum efficiency of organic light-emitting diodes is low, and the low efficiency limits the promotion of diode applications.

Images