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 Si O 2 gate insulating layers with smooth self-assembled monolayer was improved by changing the octyltrichlorosilane treatment time for the Si O 2 , which led to reproducible high field-effect mobilities of the polymerthin-film transistors up to 0.44 cm 2 ∕ V s . High stability of the transistor for repeated stressing in ambient air was also demonstrated.