The performance of perovskite solar
cells (PSCs) depends heavily
on the electronic and optical properties of the electron transport
layer (ETL). Density functional theory (DFT) uses a quantum-mechanical
approach to accurately predict the properties of different layers
in PSCs, including the ETL. Titanium dioxide (TiO2) is
a widely used material for the ETL in PSCs. In this work, we use first-principles
calculations based on DFT to obtain the electronic and optical properties
of pristine rutile TiO2 and TiO2 doped with
tin (Sn) and zinc (Zn). DFT-extracted carrier mobility, band gap,
and the absorption spectrum of TiO2 are used in the SCAPS-1D
device simulator to evaluate the performance of the solar cell device,
with respect to dopant concentration and thickness of TiO2. PSCs with 3.125 mol % Sn-doped TiO2 achieve a maximum
power conversion efficiency (PCE) of 17.14 versus 13.70% with undoped
TiO2. We have also compared the performance of PSCs with
Sn-doped and Zn-doped TiO2. For the same dopant concentration,
Sn-doped TiO2 offers 0.63% higher PCE than the Zn-doped
counterpart. The results are in good agreement with reported experimental
findings and provide a reliable means of evaluating PSC performance
by combining first-principles (DFT) calculations with conventional
device simulations.