Microscopic Property of Amorphous Semiconductor Metal Oxide InGaZnO$_{4}$ and Role of O-deficiency

TL;DR

This study uses first-principle calculations to explore the microscopic and electronic structures of amorphous InGaZnO$_{4}$, revealing that O-deficiency does not significantly affect the conduction band and can generate free carriers without donor levels.

Contribution

It provides new insights into the electronic structure of amorphous InGaZnO$_{4}$ and the role of O-deficiency, highlighting the minimal impact on conduction band states.

Findings

Few band tail states are generated in the conduction band.

Electronic structure around CBM is minimally affected by disorder.

O-deficiency can generate free carriers without donor levels.

Abstract

We investigated the microscopic and electronic structures amorphous oxide semiconductors InGaZnO$_{4}$ (a-IGZO) and the role of O-deficiency through the first-principle calculations. The structure of the amorphous oxide is complicated by the admixture of many different kinds of substructures, however it is surprisingly found that the band tail states, which are well-known to be present in the amorphous semiconductors, are few generated for the conduction band minimum (CBM). The electronic structure around CBM is little affected by the disorder and also by the O-deficiency. Free electron carriers can be generated without a creation of donor-level in the O-deficient amorphous oxide.