Improved Transistor Performance by Modulating Molecular Packing with Donor and Acceptor Moieties.

The joint of the donor and acceptor moieties allows a facile and effective strategy to develop novel organic conjugated materials. However, few pieces of work report the understanding of the donor-acceptor interactions at the molecular level. Herein, we developed three small molecules containing one acceptor motif with different amounts of the donor unit. By combining theoretical calculations and energy level characterization, the lowest unoccupied molecular orbital (LUMO) levels of the three molecules were proven to be almost identical. The molecular packing modes were evaluated from crystal structure prediction. Owing to the donor-acceptor interactions, the packing mode can be tuned from a 1D slipped stacking to a 2D brick layer. The 2D molecular packing and charge transport channel endowed the materials a higher electron mobility of 3.29 cm2  V-1  s-1 in the single-crystal field-effect transistors after such modulation.