Use of local density approximation within range separated hybrid exchange-correlation functional to investigate Pb doped SnO2

Abstract

In this study, local density approximation (LDA) was used instead of Perdew-Burke-Ernzerhof (PBE) within the standard Heyd-Scuseria-Ernzerhof (HSE) functional. Using a 29% mixing ratio, the electronic and structural properties of SnO2 were calculated in good agreement with the experimental data. Using this method, Pb doped SnO2 was investigated. The 12.5% Pb doping ratio narrows the band gap of SnO2 from 3.60 to 3.02 eV. The main reason for the band gap narrowing is the decrease in the conduction band minimum (CBM). The decrease in CBM is proportional to the Pb doping ratio. Doping with Pb does not cause a significant change in the valence band and the effective mass of electrons and holes. According to these results, doping with Pb can be a useful method to adjust the CBM of SnO2, which is used as an electron transport layer between the electrode and perovskite in perovskite solar cells.