Effect of Co content on properties of ZnO:Co3O4 nanocomposites thin films elaborated by Pneumatic Spray Pyrolysis

Abstract Optoelectronics and solar cells are an urgent challenge of the 21st century. However, much of the research has focused on single oxide thin films, leading to a limitation in practical application. Combining p and n type semiconductors represents a promising approach. This work introduces an innovative approach to produce ZnO:Co₃O₄ thin films with various Co concentrations (from 0 to 100 wt.%) by a low-cost, homemade pneumatic spray method. XRD patterns show the presence of both hexagonal wurtzite ZnO and cubic spinel Co3O4 exhibiting a preferred orientation along the (002) and (111) planes, respectively. Pure ZnO films grown by a homogenous distribution of spherical particles and high transmission in the visible region. The presence of Co leads to a decrease in the irregular distribution of grains with a decrease in transmission. The measured electrical conductivity was found to be between 10-2(Ω.cm)⁻¹ for ZnO to 1.09 (Ωcm)−1for ZnO:Co₃O₄ thin films. ZnO:Co₃O₄ films are an excellent candidate for optoelectronic applications due to their electrical conductivity, proper crystallinity, sustainability, and stability.