Exploring the Applicability of Un-doped and Doped Rutile TiO2 in
Lead-Free Perovskite Solar Cells
Abstract
On pure and metal, non-metal, co-doped rutile TiO2, DFT simula- tions
are performed. For the stability study of doped materials, the defect
formation energies of non-metal (S), metal (Fe), and metal and non-metal
(Fe/S) co-doped materials are determined. A Ti- rich environment is
preferable over an O-rich environment. With values of 2.98 eV, 2.18 eV,
1.58 eV, and 1.40 eV, the bandgap for pristine, S-doped, Fe-doped, and
Fe/S co-doped materials is found to be direct. The effective masses (m*)
and ratios (R) of charge carriers are also examined, and it is
discovered that Fe/S co-doped material has the lowest charge carrier
recombination rate. The maximum static dielectric constant is found in
the Fe/S co-doped material. Doped material’s absorption spectra shifted
into the vis- ible region. Additionally, using SCAPS-1D simulation
software, a complete solar cell device study using these materials as
ETL is performed for the first time. The absorber layer and the ETL
settings have been tweaked to perfection. Current-voltage (IV)
characteristics, quantum efficiency (QE), capacitance-voltage (CV)
characteristics, and capacitance-frequency (Cf) character- istics are
provided for optimize solar cells.When the smallest degree of defect for
each layer is taken into account, the solar cell with Fe/S co-doped ETL
has the highest efficiency of 34.27%.