OPTICAL BAND GAP OF ZnO THIN FILMS DEPOSITED BY ELECTRON BEAM EVAPORATION

Abstract

Optical band gap of ZnO thin films deposited by electron beam evaporation at evaporation rates ranging 5 Ås-1-1 to 15 Ås and thickness ranging 1000Å to 3000Å is presented. Deposited films were annealed at 573K for one and half hour. The variations in the optical band gap were observed and showed decreasing behavior from 3.15eV to 3.05 eV, from 3.18 eV to 3.10 eV and from 3.19 eV to 3.18 eV for films with respective thickness 1000Å, 2000 Å, 3000 Å on increasing the evaporation rate from 5 Ås-1 to 15 Ås-1 by keeping thickness constant.