Charge Carrier Mobilities and Singlet Fission Dynamics in Thienoquinoidal Compounds

The charge carrier mobilities and singlet fission (SF) dynamics in newly synthesized three thienoquinoidal compounds (ThBF, TThBF, and BThBF) are theoretically characterized by combining a time-dependent wavepacket diffusion method and electronic structure calculations. It is found that all three compounds have quite large electron and hole mobilities and that ThBF possesses the property of p-type semiconductor, whereas TThBF and BThBF show the behavior of n-type semiconductor. For the SF efficiency, TThBF should be the best candidate among the three molecular crystals due to a strong electronic coupling. The obvious correlation between charge carrier mobilities and the SF dynamics is not found; however, the expansion of exciton wave function in the aggregates of these compounds can accelerate the SF process, consistent with other experimental and theoretical observations.