Developing efficient red TADF molecules remains a great challenge and it is extremely urgent to reveal the luminescence mechanisms through theoretical perspectives. Herein, the photophysical properties of two pairs of red TADF isomers in toluene and solid phase have been theoretically studied. Results indicate that, compared with trans-isomers, cis-isomers possess smaller energy gaps which bring fast RISC processes. While for molecules in solid phase, decreased energy gaps and increased spin orbit coupling constants are determined, all these factors contribute to the remarkable RISC processes. Furthermore, previous experimental measurements are reasonably explained and three new red TADF molecules are theoretically proposed.

开发高效的红色TADF分子仍然是一个巨大的挑战，从理论角度揭示其发光机制迫在眉睫。本文对两对红色TADF异构体在甲苯和固相中的光物理性质进行了理论研究。结果表明，与反式异构体相比，顺式异构体具有更小的能隙，从而带来更快的RISC过程。虽然对于固相分子来说，能隙的减小和自旋轨道耦合常数的增加是确定的，所有这些因素都有助于实现卓越的 RISC 过程。此外，合理解释了先前的实验测量，并从理论上提出了三种新的红色TADF分子。