In2O3-based Transparent Conductive Oxide Films with High Electron Mobility

Abstract

We have investigated the effects of dopants (Ti, Zr, H, Sn) and growth processes for In2O3 transparent oxide films in terms of their electrical and optical properties. Ti- and Zr-doped In2O3 showed higher mobility than conventional Sn-doped In2O3 in epitaxial and polycrystalline films fabricated by vapor-phase-crystal growth. On the other hand, we have found that polycrystalline H-doped In2O3 films fabricated by crystallization of the amorphous phase at 200oC show larger mobility (130 cm2/Vs) with resistivity of 2.7×10−4 Ωcm and improved near infrared transparency. Analysis of temperature dependence of Hall mobility reveals that the high mobility in the H-doped In2O3 films is ascribable to suppression of multicharged and neutral impurities as well as grain boundary defects. Relationship between the values of room temperature Hall mobility and carrier concentration further supports our conclusion.