Effect of W and Ti on the phase transition temperature and optical properties of VO2 Analyzed by First-Principles

Abstract

In order to investigate the effects of W and Ti doping on VO₂, we investigate the energy band structure, density of states, and Helmholtz free energy of formation of pure VO₂ and doped systems (W-doped, Ti-doped, and W-Ti-codoped) using first-principles calculations in this paper. We also perform approximate calculations of the phase transition temperature and transmittance. The results show that W doping decreases the phase transition temperature to 287 K (by 15.5 %); Ti doping increases it to 356 K (by 4.7 %); W-Ti co-doping decreases it to 314 K (by 7.6 %). For the material transmittance calculations, take 750 nm wavelength as an example; W doping reduces transmittance by 13.15 %, Ti doping increases it by 8.26 %, and W-Ti codoping decreases it by 2.68 %. This suggests that there is a difference in the degree of influence of W and Ti on phase transition temperatures and transmittances. These findings provide a new theoretical approach for VO₂ preparation through W-Ti codoping.