Effect of Zr doping on the electrical and optical properties of ZnO

Highlights: • Zr doped ZnO can be converted into an n-type degenerate semiconductor. • Higher Zr doping amount results in a higher electronic effective mass. • Higher Zr doping amount can result in significant doping system conductivity. Within 0.02083–0.04167 Zr doping amount, there are contradictory reports on the experimental results of ZnO doping system in absorption spectrum distribution. However, there is no reasonable theoretical explanation until now. To solve this problem, density functional theory-based generalized gradient approximation plane wave ultra-soft pseudopotential GGA + U method is utilized in this paper and the first-principles are adopted to construct the supercell models with three different doping amounts, Zn_0.97917Zr_0.02083O, Zn_0.96875Zr_0.03125O and Zn_0.95833Zr_0.04167O. On the basis of geometrical optimization of all the models, band structure distribution, density of states distribution and absorption spectrum distribution are calculated and the calculation results show that within the limited doping amount, the higher the Zr doping amount is, the higher the doping system volume is, the higher the total energy is, the lower the system stability is, the higher the formation energy is, and the more difficult doping is. With all the doping systems converted into n-type degenerate semiconductor, the wider the doping system band gap is, the more significant the absorption spectrum blueshift is, the lower the absorption intensity is, the higher the electronic effective mass is, the higher the electronic concentration is, the lower the electronic mobility is, the higher the electronic conductivity is, and the more significant the doping system conductivity is. The calculation results and the experiment results are consistent.