Numerical Analysis of High-Efficiency Inverted Perovskite Solar Cells: Impact of ETL Selection and Device Parameter Optimization

Abstract

The following paper is a thorough simulation-driven research on inverted planar perovskite solar cells (PSCs) operating on the SCAPS-1D platform and aiming at improving the optimal performance in terms of material choice and optimization of device parameters. The device structure consists of an inorganic transport layer architecture with nickel oxide (NiOₓ) as hole transport layer (HTL), different electron transport layers (ETLs) such as titanium dioxide (TiO₂), zinc oxide (ZnO), and tin dioxide (SnO₂), and high-performance perovskite absorber layer. The effects of important parameters in the photovoltaic performance like the absorber thickness, temperature change, bulk defect density, interface recombination, and back contact materials are systematically examined. The findings prove that the ETL selection and physical parameters optimization strongly impact the device functioning. Devices based upon ZnO show higher short-circuit current density (Jsc) because of better electron mobility, and those based upon SnO₂ have better open-circuit voltage (Voc) and fill factor (FF) because of better band alignment with the absorber layer. An ideal absorber thickness is found in 600–700 nm where the highest power conversion efficiency (PCE) is ideal. More so the analysis also shows that the higher the defect density and temperature, the worse the performance of the device is because of the higher the recombination losses. The engineering of back contact is also a vital factor as the better the work function metals are the more the improved charge extraction and efficiency. The optimal device scheme is characterized by the highest efficiency of about 18–19 percent, which demonstrates the efficiency of inorganic transport layers and the use of multiple parameters. This work is also capable of offering essential understanding of how to design and optimize the high-efficiency inverted PSCs and can serve as a solid base of simulation to be used in the development of photovoltaic devices in the future.