Influence of annealing on the optoelectronic properties of sprayed p-NiO/n-CdS

Abstract

The chemical spray pyrolysis was utilized to deposit nickel oxide with a thickness of 250 nm on both glass and FTO substrates. Its characteristics were examined at a range of annealing temperatures, including 523, 623, and 723 K for one hour. Based on X-ray diffraction tests, The X-ray pattern data indicated that nickel oxide had a cubic polycrystalline structure with a favored orientation (012). The films have very smooth surfaces, and nanoscale structures were revealed using atomic force microscope measurements. Field-emission scanning electron microscope shows roughly spherical-shaped particles with granulation and an agglomeration tendency with uniformly dispersed size morphology for the deposited films. The deposited films’ transmittance spectrum of wavelengths between 400 and 1100 nm was included in the investigation of optical characteristics. The lowered absorption spectrum rate leads to the optical spectrum’s bandgap (300–700 nm) rise by (3.21,3.28,3.31,3.35) eV. Analysis of the current–voltage characteristics of heterojunctions fabricated at various annealing temperatures showed an increase in the conversion efficiency of the optoelectronic devices from 1.9 to 3.8% as the annealing temperature increased to 723 K.