Effects of Ni and La Dopants on the Properties of ZnO and SnO2 Thin Films: Microstructural, Optical and Impedance Spectroscopy Studies

The effects of Nickel (Ni) and Lanthanum (La) dopants on the structural, optical and electrical properties of ZnO and SnO 2 thin films were investigated. Both oxide materials were deposited on glass substrates using a spray pyrolysis technique. Structural analysis indicated that grain size was better increased for doped ZnO and SnO 2 with nickel than with La. Optical studies revealed that Ni- and La-doped ZnO films exhibit high transmittance of about 80–85% from the visible to infrared regions. Doping with La led to a reduction of energy band value from 3.46 eV for Ni-doped SnO 2 to 3.34 eV for La-doped SnO 2 , while La doped ZnO showed a slight increase of energy band value compared to that of Ni doped ZnO. Electrical properties were calculated using electrochemical impedance spectroscopy at room temperature.