Effect of Indium doping on the electrical properties of solution-processed Mg0.2Zn0.8O thin film transistors

Abstract

We fabricated solution-processed thin film transistors (TFTs) with In-doped Mg0.2Zn0.8O channel layers and investigated the effect of In doping on the device performance. With increasing In content in the Mg0.2Zn0.8O films, the off-current decreased and the threshold voltage shifted in the positive direction. This was due to the reduction in carrier concentration caused by In addition. Disordered atomic arrangements such as stacking faults were observed with increasing In content in the Mg0.2Zn0.8O thin films. Such structural defects could generate localized acceptor states, leading to a reduction in carrier concentration. These results suggest that In doping can be a useful technique to produce more reliable solution-processed Mg0.2Zn0.8O materials for TFTs and other applications.