Modeling and Optimization of Modified TiO₂ with Aluminum and Magnesium as ETL in MAPbI₃ Perovskite Solar Cells: SCAPS...

The perovskite device, incorporating a modified nanostructure of TiO₂ as the electron transport layer, has been investigated to enhance its performance compared to the pure TiO₂ device. Various materials undergo electrochemical doping or treatment on TiO₂ to improve their photocatalytic application, thereby enhancing the current density, minimizing recombination, and improving device stability. In this study, a numerical SCAPS simulation was employed to validate experimental findings from the literature. According to the literature, this marks the first instance of doping Al³⁺ and Mg²⁺ on TiO₂ due to their ionic radius comparable to that of Ti⁴⁺, at different doping concentrations. The device was modeled and simulated with the experimental parameters of bandgap, series, and shunt resistances for pure TiO₂, aluminum-doped TiO₂ (Al-TiO₂), and magnesium-doped TiO₂ (Mg-TiO₂). From the validated results, the Al-TiO₂ and Mg-TiO₂-based devices' configurations with minimum percentage errors of 0.427 and 2.771%, respectively, were selected and simulated across nearly 90 (90) configurations to determine the optimum device model. Optimizing absorber thickness, bandgap, doping concentration, metal electrode, as well as series and shunt resistance resulted in enhanced device performance. According to the proposed model, Al-TiO₂ and Mg-TiO₂ configurations achieved higher power conversion efficiency values of 19.260 and 19.860%, respectively. This improvement is attributed to the reduction in recombination rates through the injection of a higher photocurrent density.