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 Γ 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 fluorine 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 fluorine-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.

Keywords

• DFT, TiO2, Fluorine, electronic properties, solar cells