CH3NH3SnI3${\mathrm{CH}}_{\mathrm{3}}{\mathrm{NH}}_{\mathrm{3}}{\mathrm{SnI}}_{\mathrm{3}}$: Superior Light Absorption and Optimized Device Architecture with 31.93% Efficiency

• Published in: Advanced theory and simulations Vol. 7; no. 8
• Main Authors: Hajjami, M., Chabri, I., Oubelkacem, A., Benhouria, Y., Kaiba, A., Essaoudi, I., Ainane, A.
• Format: Journal Article
• Language: English
• Published: 01-08-2024
• Subjects: CH3NH3SnX3${\mathrm{\ CH}}_{\mathrm{3}}{\mathrm{NH}}_{\mathrm{3}}{\mathrm{SnX}}_{\mathrm{3}}$ (X = I, Br, Cl); electronic proprieties; optical proprieties, quantum espresso software; SCAPS‐1D software, Schottky junction
• ISSN: 2513-0390; 2513-0390
• DOI: 10.1002/adts.202400129

This research investigates and optimizes the CH3NH3SnI3${\mathrm{CH}}_{\mathrm{3}}{\mathrm{NH}}_{\mathrm{3}}{\mathrm{SnI}}_{\mathrm{3}}$ perovskite solar cells. Initially, optoelectronic parameters of perovskite absorber materials, including CH3NH3SnI3${\mathrm{CH}}_{\mathrm{3}}{\mathrm{NH}}_{\mathrm{3}}{\mathrm{SnI}}_{\mathrm{3}}$, CH3NH3SnBr3${\mathrm{CH}}_{\mathrm{3}}{\mathrm{NH}}_{\mathrm{3}}{\mathrm{SnBr}}_{\mathrm{3}}$, and CH3NH3SnCl3${\mathrm{CH}}_{\mathrm{3}}{\mathrm{NH}}_{\mathrm{3}}{\mathrm{SnCl}}_{\mathrm{3}}$, 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. CH3NH3SnI3${\mathrm{CH}}_{\mathrm{3}}{\mathrm{NH}}_{\mathrm{3}}{\mathrm{SnI}}_{\mathrm{3}}$ shows superior optical characteristics, surpassing CH3NH3SnBr3${\mathrm{CH}}_{\mathrm{3}}{\mathrm{NH}}_{\mathrm{3}}{\mathrm{SnBr}}_{\mathrm{3}}$ and CH3NH3SnCl3${\mathrm{CH}}_{\mathrm{3}}{\mathrm{NH}}_{\mathrm{3}}{\mathrm{SnCl}}_{\mathrm{3}}$, and demonstrating more effective absorption within the visible spectrum than CH3NH3PbI3${\mathrm{CH}}_{\mathrm{3}}{\mathrm{NH}}_{\mathrm{3}}{\mathrm{PbI}}_{\mathrm{3}}$. Subsequently, a numerical analysis is conducted for a P–I–N configuration Fluorine doped Tin Oxide (FTO)/TiO2${\mathrm{TiO}}_{\mathrm{2}}$/CH3NH3SnX3${\mathrm{CH}}_{\mathrm{3}}{\mathrm{NH}}_{\mathrm{3}}{\mathrm{SnX}}_{\mathrm{3}}$/Cu2O${\mathrm{Cu}}_{\mathrm{2}}{\mathrm{O}}$/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 (Nt${{\mathrm{N}}}_{\mathrm{t}}$) of 1015${\mathrm{1}}{{\mathrm{0}}}^{{\mathrm{15}}}$ cm−3${\mathrm{cm}}^{ - {\mathrm{3\ }}}$ for optimal performance, coupled with an absorber thickness of 1 µm. Examining the transformation from Sn2+${\mathrm{Sn}}^{{\mathrm{2 + }}\ }$ to Sn4+${\mathrm{Sn}}^{{\mathrm{4 + }}\ }$ 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.
The study begins with estimating optoelectronic parameters of CH3NH3SnI3, CH3NH3SnBr3, and CH3NH3SnCl3 using DFT in Quantum Espresso. CH3NH3SnI3 emerges as the most promising perovskite material, selected for a P–I–N solar cell configuration (FTO/TiO2/CH3NH3SnI3/Cu2O/anode). Subsequently, SCAPS‐1D software is employed for numerical analysis and optimization of device parameters like absorber thickness and defect density, aiming to achieve high performance and stability.