Exploring the hole mobility of oligothiophene based donors with different spatial symmetry and conjugation length of backbone: A theoretical insight

Abstract Novel oligothiophene based donors have been synthesized and modified. However, how molecular modifications influence their molecular stacking and charge carrier mobility is not clear. In this work, we have selected two high‐performance oligothiophene based donors DRCN5T and DRCN6T to understand why the hole mobility of DRCN5T/PC71BM is much faster than that of DRCN6T/PC71BM in the experiment (Journal of the American Chemical Society, 2015). The computed data indicate that the maximum hole mobility of DRCN5T is about 20 times faster than that of DRCN6T. Moreover, DRCN5T has faster hole mobility than DRCN6T in almost every similar configuration. These mobility differences can be explained with the different positions and sparsity of side alkyl chains on the backbones. The work here gives a deep insight into the hole mobility in oligothiophene based OSCs and thereby may provide a guideline for future oligothiophene‐based donor material design and morphology control.