Performance evaluation of inorganic Cs₃Bi₂I₉-based perovskite solar cells with BaSnO₃ charge transport layer

Abstract This research embedded with a novel idea of integration of perovskite material as charge transport layer corresponding to the perovskite absorber layer. The study explores the effectiveness of BaSnO3 perovskite material as an electron transport layer (ETL) in Cs3Bi2I9-based perovskite solar cells, using SCAPS-1D simulations. The research meticulously examines how structural and optical variations in each layer affect the device’s performance indicators, finding the thickness of the Cs3Bi2I9 layer and its defect concentration pivotal for optimal functionality. The highest photovoltaic efficiency, 20.62%, was achieved with an absorber layer thickness of 0.8 micrometers and acceptor and donor concentrations between 1E17 /cm3 and 1E18 /cm3, respectively. The absorber’s bulk defect density optimally ranged from 1E14 /cm3 to 1E15 /cm3. Interface defects between BaSnO3 and Cs3Bi2I9 layers significantly influenced performance, more so than those at the HTL (Cu2O) interface. The study also assesses thermal effects and series and shunt resistances, aiming to mitigate potential induced degradation (PID), a key concern for solar cell longevity and reliability. Nickel (Ni) was chosen as the back contact metal, balancing cost and efficiency. This research intends to clarify PID conditions to enhance the durability and consistent performance of photovoltaic systems.