Electrical and Optical Properties of In-doped ZnO Thin Films via Ultrasonic Spray Pyrolysis

In-doped ZnO (IZO) thin films have been deposited onto glass substrates by the ultrasonic spray pyrolysis method. The variations of the electrical and optical properties with the indium incorporation were investigated. The optical transmittance through the films was measured in the wavelength range 300-1000 nm with the help of an UV-VIS spectrophotometer. The average optical transmittance of 3 at % indium-doped ZnO thin films was over 80% in the visible range. All the deposited films were polycrystalline in nature. The direct optical band gap value was found to be varying between 3.41 to 3.43 eV. The electrical sheet resistance values were obtained by the four probe method. The variation of substrate temperature as well as the incorporation of indium in the ZnO lattice affects the electrical resistivity.