Accurate Prediction for Dynamic Hybrid Local and Charge Transfer Excited States from Optimally Tuned Range-Separated Density Functionals

Abstract

Fine regulation of excited-state characteristics of organic molecules plays a vital role in the rational design of novel optoelectronic materials. Recently, the fluorescent emitters with a hybridized local and charge transfer (HLCT)-excited state have attracted significant interest in developing high-efficiency organic light-emitting diodes. The HLCT state generally consists of a mixture of local excitation and charge transfer (CT) characters that are known to be sensitive to molecular configuration and surrounding environment. Thus, both qualitative and quantitative characterizations of “dynamic” HLCT states remain challenging from a theoretical perspective. In this work, a series of donor–acceptor (D–A) molecules with HLCT excited-state characters were theoretically studied using density functional theory (DFT) and time-dependent DFT. Successful prediction of both vertical absorption and emission excitation energies (EVA and EVE) of the lowest singlet excited state (S1) is demonstrated when using the op...