Performance evaluation of all-inorganic cesium-based perovskite solar cell with BaSnO3 as ETL

Abstract

All-inorganic cesium tin-germanium tri-iodide (CsSnGeI₃) emerges as a potential light harvesting material for lead-free perovskite solar cells. The exploration of CsSnGeI₃ has not yet been perceived owing to the conceivable challenges of imperfections in device fabrication, unoptimized alignment of the charge transport layers, and inappropriate device configuration. In this manuscript, we have elucidated the influence of BaSnO₃ as an electron transport layer on the performance of Pb-free, all-inorganic cesium tin-germanium tri-iodide (CsSn_0.5Ge_0.5I₃)-based perovskite solar cell using SCAPS-1D software. In our initial simulated results, the presented device achieves the best efficiency of 22.09% with J_SC = 24.41 mAcm⁻², V_OC = 1.0655 V, and FF = 84.92%. Subsequently, we have analyzed the impact of thickness and defect density on the recombination rate of charge carriers in the Sn-Ge amalgamated perovskite absorber layer, diffusion length, and other performance parameters. From these results, we have optimized the suitable value of thickness (900 nm) and defect density (N_t ≈ 1×10¹¹ cm⁻³) of Sn-Ge combination perovskite layer for efficient PVSCs devices. Furthermore, we have optimized the thickness, electron affinity, and carrier concentration of charge transport layers, and their optimized values have been obtained for the design of efficient device. Using the optimized values, proposed device yields the high performance in terms of best power conversion efficiency of 28.21% with J_SC = 27.18 mAcm⁻², V_OC = 1.2427 V, and FF = 83.50%, without any hysteresis loss. Thus, this extensive simulation approach paves a formative research route for the practical fabrication of efficient Pb-free CsSnGeI₃ perovskite-based solar cells.

Graphical abstract