CH₃NH₃SnI₃: Superior Light Absorption and Optimized Device Architecture with 31.93% Efficiency

This research investigates and optimizes the (Formula presented.) perovskite solar cells. Initially, optoelectronic parameters of perovskite absorber materials, including (Formula presented.), (Formula presented.), and (Formula presented.), are estimated using Density Functional Theory (DFT) principles implemented in the Quantum Espresso software. The absorption of light energy is examined, detailing electron transitions between the highest p energy states of halogens (I, Br, and Cl) in the VB and the lowest 5p energy states of tin in the CB. (Formula presented.) shows superior optical characteristics, surpassing (Formula presented.) and (Formula presented.), and demonstrating more effective absorption within the visible spectrum than (Formula presented.). Subsequently, a numerical analysis is conducted for a P–I–N configuration Fluorine doped Tin Oxide (FTO)/ (Formula presented.) / (Formula presented.) / (Formula presented.) /Anode using SCAPS-1D software. The optimization process focuses on absorber thickness, defect density, acceptor density, and the work function (WF) of the anode materials. Simulation findings recommend a defect density ((Formula presented.)) of (Formula presented.) (Formula presented.) for optimal performance, coupled with an absorber thickness of 1 µm. Examining the transformation from (Formula presented.) to (Formula presented.) through oxidation reveals that reducing the concentration of acceptors in the absorber layer (NA) significantly enhances device performance. Superior performance is achieved by a high WF anode material. This study not only contributes to advancing our understanding of lead-free perovskite optoelectronics but also provides valuable insights for the development of highly efficient and stable solar cells.