High-mobility and air-stable organic thin-film transistors with highly ordered semiconducting polymer films

Abstract

We report on high crystalline thin films of liquid-crystalline polythiophene derivative, poly(2,5-bis(3-hexadecylthiophene-2-yl)thieno[3,2-b]thiophene) (PB16TTT) that exhibit terrace structures and molecular steps of its polymer chains by annealing in its liquid-crystalline phase. The crystallinity of the PB16TTT polymer films formed on SiO2 gate insulating layers with smooth self-assembled monolayer was improved by changing the octyltrichlorosilane treatment time for the SiO2, which led to reproducible high field-effect mobilities of the polymer thin-film transistors up to 0.44cm2∕Vs. High stability of the transistor for repeated stressing in ambient air was also demonstrated.