Effect of indium concentration on optical and electrical properties of in doped ZnO thin films for gas sensing application

The deposition of Indium doped ZnO thin films using sol gel spin coating technique will be discussed in this paper. The concentrations of indium doping of the thin films were varied from 1.0-5.0 at. % indium. The effect of various doping concentrations 1.0-5.0 at. % indium on electrical, optical properties and gas sensing application were studied. The electrical properties were analyzed using I-V measurement (CEP2400). The optical transmittance and optical band gap were characterized by ultraviolet visible (UVVIS) spectrophotometer. Gold (Au) was used as a metal contact using electron beam thermal evaporator (ULVAC). The optical result show that the indium doped ZnO thin films revealed higher than 90% of transmittance value. The highest electrical resistivity was found 1.95E+04 £lcm at. 2% indium concentration. The optimum result of Indium doped ZnO thin films will be used for gas sensing application and gas sensitivity of the thin films will be extensively discussed in this paper.