Field-Effect Transistors Based on Tetraphenyldipyranylidenes and the Sulfur Analogues

Tetraphenyldipyranylidene 1a and its derivatives were used as organic semiconductors of OFETs for the first time. The parent compound 1a and its sulfur analogue 2a afforded good performance p-type FETs. The sulfur compound 2a showed a better performance than 1a because of the higher crystallinity. Halogen substituent and alkyl groups were introduced to the phenyl group of 1a to increase the stability and solubility.