Thermodynamics of native defects in V2O5 crystal: A first-principles method

Abstract

The defect formation energy and its stability of native point defects in V2O5 are systematically investigated utilizing the DFT + U method and thermodynamic calculations over a range of temperatures, oxygen partial pressures and stoichiometries. The variation of the formation energy for different charged point defects with Fermi level is also discussed in great detail. The findings demonstrate that donors are deep-level defects and provide minimal contributions to an n-type conductivity. Acceptor exhibits shallow-level transition that is easily compensated from the donors and makes intrinsic p-type doping challenging. Furthermore, all the native point defects in V2O5 are extremely sensitive to temperature, oxygen partial pressure and Fermi level. The distribution of the most stable point defects that may exist in crystals in the three-dimensional space of temperature, oxygen partial pressure, and Fermi level has been obtained. The calculated results offer a clear picture for analyzing the different types of point defects that may appear in crystals under different conditions and serves as a guide for regulating the formation of crystal point defects.