A Study of Temperature Dependence of Field-effect Mobility in Solution-processed Organic Field-effect Transistors

Abstract

Carrier transport in solution-processed organic field-effect transistors (OFETs) based ondioctylbenzothienobenzothiophene (C₈-BTBT) has been investigated in a wide temperature range from 300 to 10K. The field-effect mobility shows thermally activated behavior whose activation energy becomes smaller with decreasing temperature. The results indicate thathopping transport between isoenergetic localized states becomes dominated in a low temperature regime. Numerical simulation has been carried out to explain the temperature dependence of the mobility using a hopping transport model based on the effective transport energy concept [V. I. Arkhipov, et al., Appl. Phys. Lett. 82 (2003) 3245]. The numerical calculation is in good agreement with the present experimental results.