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

Abstract

The effects of Nickel (Ni) and Lanthanum (La) dopants on the structural, optical and electrical properties of ZnO and SnO2 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 SnO2 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 SnO2 to 3.34 eV for La-doped SnO2, 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.