Characterization of semiconductor properties and applications of Mg-doped ZnCo2O4 spinel-structured thin films

This study investigates the enhancement of semiconductor properties in spinel Zn(MgxCo1-x)2O4 thin films through magnesium doping, examining its impact on structure, optoelectronic properties, and antibacterial characteristics. Magnesium doping up to Mgx = 0.17 in ZnCo2O4 films maintains spinel structures without forming Mg-related phases. Doping reduces lattice regularity, crystallite size, and surface roughness, resulting in a composite microstructure with nano-grain and amorphous Zn-Co-O. Film transmittance is affected by surface roughness and grain boundary. The intrinsic band gap of ZnCo2O4 thin film was 2.10 eV, which decreased to a range of 2.02–2.09 eV after magnesium doping. Extrinsic Mg doping introduces hole carriers, elevating carrier concentration from 2.17 × 1017 cm−3 (undoped, Mgx = 0.00) to 8.17 × 1017 cm−3 (Mgx = 0.11). ZnCo2O4 exhibits excellent antibacterial properties against Escherichia coli and Staphylococcus aureus, with a more than 99 % antibacterial rate. These findings indicate the potential utilization of ZnCo2O4:Mg in various optoelectronic and biomedical semiconductor materials and components.