Design strategy for blue thermally activated delayed fluorescence: Position and methyl substitutions

Abstract

Wise design strategies for efficient blue TADF molecules are highly desired. In this work, the position effect and methyl substitution effect on the photophysical properties of nine blue TADF molecules are studied. Results show that the introduction of methyl in acceptor unit brings remarkable blue shit for emission. Meanwhile, substitution by methyl in donor unit can bring remarkable TADF properties by facilitating the reverse intersystem crossing and radiative decay processes. Thus, the TADF properties can be improved by the substitution of methyl group in donor unit and deep blue luminescence can be achieved through the substitution effect in acceptor unit.