Transparent amorphous oxide semiconductors: Materials design, electronic structure, and device applications

Abstract

In 1995, I presented a materials design concept for transparent amorphous oxide semiconductors with a large electron mobility (TAOS) at the 16'h International conference on amorphous semiconductors along with concrete example materials of TAOS and the paper was published in 1996 [1[. The basic concept of TAOS is that large electron mobility should be retained even in amorphous materials if the conduction band minimum is mainly composed of spatially large spread of metal ns-orbitals.1 The validity of this design concept was demonstrated by analysis of electronic structure using photoemission experiments combined with calculations based on X-ray structural analysis[2].