| abstract |
The present invention belongs to the technical field of OLED and provides a compound used as a host material, having the structure of formula (I); wherein m and n represent the number of electron donor D and electron acceptor A, respectively, and are selected from 1, 2 or 3, p and q are independently selected from 0, 1 or 2; L 1 , L 2 and electron donor D are each independently selected from alkyl, cycloalkyl, heterocyclyl, aryl, heteroaryl, fused aryl The electron acceptor A is selected from nitrogen-containing heterocycles, cyano-containing, phosphorus-containing oxygen-containing substituents or triarylboron-based substituents. The D-(π)-σ-(π)-A structure in the compound of the present invention has bipolarity, and the σ bond can effectively interrupt the intramolecular charge transfer between the electron donor D and the electron acceptor A, and make the excited state It is limited to the local excited state within the fragment of D or A, so that the compound has a small excited state dipole moment, when it is used as the host material of the light-emitting layer, it can effectively reduce the efficiency roll-off of the blue light material, improve the luminous brightness and Luminous efficiency. |