Optimizing molecular orientation for high performance organic thin film transistors based on titanyl phthalocyanine

Abstract

In this paper, organic thin film transistors based on titanyl phthalocyanine were fabricated on octadecyltrichlorosilane (OTS) stripe modified Si/SiO₂ substrates. The p-type transistor exhibited high performance with a hole mobility of ∼4.25 cm²V⁻¹s⁻¹ and an on/off ratio greater than 3.1 × 10⁷ on 1 µm wide OTS stripe modified substrates. The charge transport anisotropy was observed in devices fabricated with channels parallel and perpendicular to the OTS stripes, indicating that the molecular orientation was optimized and arranged in a more ordered style. The high performance of the devices showed their potential for application in organic circuits.