Variation of optical and electrical properties of amorphous In–Ga–Zn–O/Ag/amorphous In–Ga–Zn–O depending on Ag thickness

Abstract

Optical and electrical properties of amorphous In–Ga–Zn–O based oxide–metal–oxide (OMO) multilayer with embedded Ag film have been investigated. It was found that the optical band gap (Eg) of the OMO film was linearly widened as increasing Ag thickness ranging from 8nm to 18nm, while the Eg was narrowed beyond 18nm thick Ag film. The mechanism for Eg widening and narrowing in OMO multilayer has been discussed in terms of Burstein–Moss effect and the potential fluctuations by Ag atoms distributed at the interface between oxide and Ag layer, mainly due to the change of carrier concentration and mobility of OMO multilayer. Especially, amorphous In–Ga–Zn–O showed good surface roughness, which can suppress admittance of ultraviolet and enhance performances needed for practical low-emissivity coating mainly due to amorphous property of thin films.