Carrier-suppressing effect of scandium in InZnO systems for solution-processed thin film transistors

Abstract

The carrier-suppressing effect of Sc in InZnO systems was studied using thin-film transistors (TFTs) with a sol-gel processed active channel. As the amount of Sc content increased, the off current decreased, and the threshold voltage shifted to a positive bias region. The Sc effectively controlled the oxygen vacancies and supplied free electrons. X-ray photoelectron spectroscopy (XPS) verified that the vacancy-related oxygen 1s peak decreased with increasing Sc content. The TFT performance with 14% Sc showed that a field-effect mobility and on-off ratio were 2.06 cm2/V s and 8.02×106, respectively.