Effect of indium doping on the optical properties and laser damage resistance of ZnO thin films

Abstract

In this paper, pure and In-doped ZnO thin films were deposited by sol-gel dip-coating technique on glass substrates. The effect of In doping on the structural, optical, morphological properties and laser damage resistance of ZnO thin films was investigated. The thickness and optical constants were calculated using Swanepoel method. All samples show hexagonal wurtzite structure and high optical transmittance about 90% in the visible range. The indium incorporation reduced the refractive index and the band gap of ZnO thin films. The Brewster angle determined by reflected light was measured to be around (ΨB)=64° for undoped film and 63° for IZN (8%at) thin film. It was also found that indium doping modified the surface morphology and decreased the grains size of ZnO thin films. The laser damage resistance of the films was studied using Nd:YAG laser (1064), then the damage morphologies was observed by an optical microscope. The LIDT was measured to be around 12.8j/cm2 for undoped film and 8.0j/cm2 for indium doped ZnO film.