Unexpected improved conductivity and systematic low-temperature anomalies of a new germanium zinc indium oxide system

Abstract

The structure, electrical conduction behaviour, optical transmittance and Haacke figure of merit (FOM) of the Ge-Zn-In-O compound are investigated for the first time. Certain Ge-Zn-In-O compounds with Ge/(Ge + Zn + In) atomic ratio even greater than 10%, denoted as a-GeZnInO, can have a surprisingly 2 times higher conductivity than indium zinc oxide (IZO) with industrial standard indium/zinc atomic ratio of 83/17 (IZO83/17). With varying Ge concentration, unexpected appearance and disappearance of the crystalline In2O3 phase and systematic low-temperature resistivity anomalies (semiconductor-metal transition) were observed and interpreted.