A combined luminescent material and its application

Abstract

The invention discloses a combined luminescent material and application thereof, belonging to the technical field of luminescent materials. The combined luminescent material of the present invention includes: a host material and a guest material; the horizontal orientation degree of the transition dipole moment of the host material is >80%; and the guest material is at least one of a thermally activated delayed fluorescent material and a traditional fluorescent material. In the present invention, a host material with a horizontal orientation degree of transition dipole moment>80% is combined with a luminescent guest material, the host material can sensitize the guest material, thereby improving the horizontal orientation degree of the transition dipole moment of the guest material, and the material is used for luminescence After the diode, the light extraction efficiency and external quantum efficiency of the diode can be improved.

Description

technical field [0001] The invention belongs to the technical field of luminescent materials, and particularly relates to a combined luminescent material and its application. Background technique [0002] Organic light-emitting diodes (OLEDs) have the advantages of high color contrast, fast response speed, low power consumption, no blue light hazard, and flexible display. They have been applied in solid-state lighting and display fields, and have good application prospects. [0003] The existing organic light-emitting materials mainly include: In 1998, Professor Forrest of Princeton University developed phosphorescent materials containing heavy metal atoms, and in 2008, Professor Adachi of Kyushu University in Japan developed a thermal activation delay with a small single triplet energy gap. fluorescent material. All of these materials can effectively utilize triplet excitons to achieve light emission, and can theoretically achieve 100% internal quantum efficiency, which me...

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.

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