Achieving significant improvements in efficiency of CsSnI3-based solar cells through interfacial engineering design modifications using SCAPS 1D and DFT simulation

Abstract

Perovskite solar cell technology approaches the brink of commercialization, the issue of organic materials and toxic remains a concern. CsSnI₃, with its eco-friendly nature, optimal 1.3 eV band gap, high carrier mobility, and Sn-enhanced stability, stands out as a promising alternative. However, its experimental efficiency is hindered by issues like energy band misalignment, high carrier concentration, and defects. In this work, we present a modification to the structure of a CsSnI₃/TiO₂ solar cell to tackle its low experimental efficiency. This proposed design focuses on achieving optimal energy band alignment and reducing bulk recombination by optimizing the band gap, conduction band offset, carrier mobility, and defect density within the absorber bulk. Additionally, it aims to mitigate interfacial recombination by inserting a thin intrinsic layer at the CsSnI₃/TiO₂ interface. The modifications to the CsSnI₃ solar cell architecture have significantly increased its efficiency to 24.54%, up from the previously reported 12.96%.