Effect of Li Doping on Structural, Optical, and Electrical Properties of CuO Thin Films Produced by Spray Pyrolysis Method

In the present work, structural, optical, and electrical properties of lithium-doped (0–6 at.%) copper oxide thin films were investigated. The films were obtained by the spray pyrolysis method on glass substrates at 450°C. The X-ray diffraction method, UV-visible spectroscopy, and the four-point probe technique were used to analyze the films. Based on the X-ray diffraction investigations, it was found that the polycrystalline films have monoclinic phases with preferred (111) and (-111) crystallographic planes. The incorporation of lithium doping into the copper oxide thin film yielded crystallite sizes of approximately 2 nm. The estimated optical band gap values are decreased from 1.88 to 1.64 eV with increasing lithium concentration. Four-point probe studies revealed that the resistivity of the films decreased from 339 to 186 K Ω cm with increasing lithium concentration.