Evaluation of Ni0.94Zn0.06O thin film performance and characterization for optoelectronic applications: Structural, optical, and electrical perspectives

Abstract

Ni_0.94Zn_0.06O films grown at 723 K on clean glass substrates via spray pyrolysis technique, thereafter, the deposited films were annealed at temperatures of 773, and 823 K respectively, for 1 hr. The deposited films were structurally characterized using X-ray diffraction (XRD), a field emission scanning electron microscope (FE-SEM) interfaced with energy-dispersive X-ray spectroscopy (EDAX) and a high-resolution transmission electron microscope (HRTEM),). The prepared films are found to belong to cubic structures based on X-ray data. An increase in particle size with increasing temperature was found by evaluating the variation of the particle size D, strain, ε and dislocation density, δ as a function of the annealing temperatures. The analysis of the optical transmission spectra in the 200–2500 nm wavelength range shows that the refractive index n increases with the annealing temperature, but the optical band gap E_g value decreases. Two different types of conduction mechanisms are revealed by the film resistance dependence of temperature measured between 300 and 600 K. For these types, the activation energy ΔE_g values decrease as the annealing temperature increases.