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.
Kater et al. (Thu,) studied this question.