Oxygen-bridged boron derivatives as electron transport and thermally activated delayed fluorescence host materials for high-performance phosphorescent organic light-emitting diodes

Oxygen-bridged boron derivatives 3,11-di(9 H -carbazol-9-yl)-5,9-dioxa-13 b -boranaphtho[3,2,1- de ]anthracene and 2,12-di(9 H -carbazol-9-yl)-5,9-dioxa-13 b -boranaphtho[3,2,1- de ]anthracene were successfully developed as n-type (electron transport type) hosts with TADF characteristics.