Experimental and computational study on Cs3Bi2I9 perovskite solar cell: A comparison of device performance

The moisture and temperature instability and toxicity associated with the Pb-based halide perovskites have paved the way for Pb-free perovskites as potential light absorbers in photovoltaics. Herein, a Cs3Bi2I9-based perovskite solar cell (PSC) is designed computationally and compared with an experimentally fabricated device. The device is simulated and optimized with different absorber thicknesses and electron transport materials (ETM). The most suitable ETM is TiO2, with an absorber thickness of 800 nm. The optical properties of Cs3Bi2I9 are investigated with UV–vis DRS and PL spectroscopy. The optimized device architecture is fabricated under ambient conditions and showed a power conversion efficiency (PCE) of 0.83%. Employing compositional engineering techniques in Cs3Bi2I9 perovskite with further optimization could lead us to more efficient solar cells in the future.