First-principles investigation of Bi and Sb-doped ZnO: Electronic, optical and mechanical insights

This study examines the impact of substitutional doping of Bi and Sb on the structural, electronic, mechanical and optical properties of ZnO, using first-principles density functional theory (DFT) calculations. Introducing dopants causes a transition from semiconductor to metal, mainly based on the reduction of the band gap and rise in carrier concentration. Thermal stability of the material is well confirmed with the aid of ab initio molecular dynamics (AIMD) simulations; elastic constants show greater stiffness and greater ductility. Marked charge redistribution is reported by the results obtained from electron density difference (EDD) analysis; the Bi–O interactions show stronger polarization effects than those for the Sb–O interactions. In the end, such changes in electronic structure increase optical properties: Incorporation of Bi enhances UV absorption and reflectivity, whereas Sb enhances absorption peaks utilizing defect-state transitions. Therefore, the sophistication of ZnO’s properties using dopant engineering makes it a promising candidate for optoelectronic and energy applications.