Atomic and electronic structures of charge-doping VO(2): first-principles calculations

The atomic and electronic structures of charge-doping VO(2) are investigated by using first-principles calculations. Hole doping is more conducive to stabilizing the structure of VO(2) than electron doping. The controllable phase transition temperature is coupled with changes in atomic and electronic structures. With the increase in hole density, the V–V chains and twisting angle experience a dramatic change, and the band gap (0.69–0 eV) is rapidly reduced due to orbital switching between the d(x(2)−y(2)) and d(z(2))/d(yz) orbitals. However, as the electron density increases, the band gap (0.69–0.502 eV) narrows slightly, while the V–O bond lengths significantly increase. The current results provide up a variable way to tune the VO(2) phase transition temperature through charge-doping.