First-principles calculations of Fluorine-doped Titanium dioxide: A prospective material for solar cells application

Abstract

This study focuses on the anatase TiO₂ doped Fluorine to investigate their structural and electronics properties using Density Functional Theory (DFT) within generalized gradient approximation (GGA) as implemented in Quantum ESPRESSO (QE). For the anatase TiO₂ phase the calculated electronic band structures of pure TiO₂ and TiO₂ doped Fluorine nanocrystals are displayed along a high symmetry directions and the energy range of band structure is plotted from 0.0 eV to 3.9 eV , the energy separation between the bottom of the conduction band and the top of valence band occurred at the ? and  points, indicating that  anatase TiO₂ is an indirect band gap material with an approximate value of 2.30 eV energy gap, this value is consistent with previous DFT result. When F is added the band structure did not change much because ?uorine element doping is conducive to the generation of Oxygen holes and enhances the mobility of effective electrons which can enhance the conductivity of the adsorbent substrate and improve the solar cell performance of the ?uorine-doped TiO₂. The band gap value obtained for F doped TiO₂ was found to be 2.11 eV. The dopant formation energy of Fluorine is calculated to be -55.6 Ry which is equivalent to -756.5 eV.