π-Extended regioisomeric dithienoacene-fused pyrenes: structures, properties, and application in field-effect transistors

Abstract

The development of π-conjugated semiconducting molecules with fused rings has been a focus of research in organic electronics. In this study, the optoelectronic and field-effect transistor (FET) properties of two novel regioisomeric dithienoacene-fused pyrenes (PDTAs) were investigated and compared. The PDTA with a substituent at the 2-position (2-SS-PDTA) demonstrates a shorter π-stacking distance and S⋯H contacts, as well as larger electron delocalization and transfer integral by theoretical calculations, compared to the 1-position substituted PDTA (1-SS-PDTA). The combination of these factors results in 2-SS-PDTA single-crystal FETs exhibiting a superior mobility of up to 1.35 cm² V⁻¹ s⁻¹. Our work provides guidelines for further advancing high-performance organic semiconductors based on the pyrene skeleton with extended π-conjugation.