Transparent flexible transistor using amorphous oxide semiconductors as channel layer

Abstract

Recently we have reported the room temperature fabrication of transparent and flexible thin film transistors (TFTs) using an amorphous oxide semiconductor (AOS) in an In₂O₃-ZnO-Ga₂O₃ system on a polyethylene terephthalate thin film substrate. These transistors exhibit a field effect mobility of 〜10 cm²/(Vs), which is higher by an order of magnitude than that of amorphous Si:H and pentacene, and a high chemical stability in an ambient atmosphere. In this article we describe the electron transport properties of ionic amorphous oxide semiconductors and compare them with those of conventional amorphous semiconductors. The unique electron transport properties are explained in terms of the chemical bonding nature of the amorphous structure. A material design concept of the AOS desired as the channel layer in TFTs and the performance characteristics of the TFTs fabricated are shown.