Phenyl Derivative of Dibenzothiopheno[6,5‐b:6′,5′‐f]Thieno[3,2‐b]Thiophene (DPh‐DBTTT): High Thermally Durable Organic Semiconductor for High‐Performance Organic Field‐Effect Transistors

Abstract Phenyl‐substituted heteroacene, diphenyl‐dibenzothiopheno[6,5‐b:6′,5′‐f]thieno[3,2‐b]thiophene (DPh‐DBTTT), is introduced as a thermally durable high‐performance organic semiconductor. The DPh‐DBTTT single crystals exhibit hole mobility up to 31.9 cm2 V−1 s−1, and the vacuum‐deposited DPh‐DBTTT thin‐film transistors show a maximum mobility of 6.32 cm2 V−1 s−1. X‐ray crystallographic analysis reveals that the small tilting angle between the phenyl substituent and the DBTTT core reduces the reorganization energy dramatically. The structure–property relationships are thoroughly investigated using atomic force microscopy, transmission electron microscopy, and grazing incidence X‐ray diffraction analyses, in addition to charge‐transport studies. The vacuum‐deposited DPh‐DBTTT thin‐film transistors show superior thermal durability compared to the core DBTTT, which is highly valuable f…