Heterojunction oxide thin film transistors: a review of recent advances

Abstract

In the last decades, oxide thin-film transistors (TFTs) have been extensively developed for optoelectronic applications owing to their outstanding electrical properties, such as excellent optical transparency and high thermal stability. Among various oxide TFTs, heterojunction oxide TFTs are regarded as notable materials because they simultaneously exhibit high charge mobility and excellent operational stability through the formation of a charge-accumulation layer. This review focuses on recent advances in heterojunction oxide TFTs. First, a fundamental understanding of the electronic structures, operations, defect chemistry, charge-accumulation mechanisms, and charge-transport mechanisms of oxide TFTs is presented. Subsequently, an overview of the recent research advances in heterojunction oxide TFTs based on various deposition methods, including vacuum and solution processing, is presented. In particular, the mechanisms of the charge-accumulation layer formation and basic characteristics of heterojunction oxide TFTs are reviewed. Finally, the prospects for heterojunction oxide TFTs are discussed.