Unlocking the Potential of WS2 as an Electron Transport Layer in Lead-Free Methylammonium Tin Iodide-Based Perovskite Solar Cells: A Comprehensive Defect Study Using the SCAPS-1D Framework
Abstract
The hazardous lead component in perovskite solar cells (PSCs) has raised environmental concerns, hindering commercialization. A simulation study is performed using a lead-free, eco-friendly ITO/WS2/MASnI3/NiO/Au PSC structure using SCAPS-1D software. This structure utilizes tungsten disulfide (WS2) as an electron transport layer (ETL), methylammonium tin iodide (MASnI3) as an absorber layer, and nickel oxide (NiO) as a hole transport layer (HTL). The study found the optimized bandgap for the WS2 layer to be 1.6 eV, with an optimized thickness of 0.5 µm. The highest permissible defect density in the WS2 interface is 1015 cm−3, while in the WS2/MASnI3 interface, it is lower at 1011 cm−3. High defect density reduces the photo conversion efficiency (PCE) of the PSCs. The simulated PSC structure has a lower activation energy of 1.08 eV, indicating an interface recombination center. The optimized device achieved a PSC efficiency of 28.15 %, a VOC value of 0.96 V, and a fill factor (FF) of 83.36%. Notably, the PCE increased to 28.58% at a lower temperature of 280 K. This breakthrough underscores the potential of WS2 as an efficient ETL in eco-friendly PSCs for non-toxic renewable energy solutions.
Abstract
The hazardous lead component in perovskite solar cells (PSCs) has raised environmental concerns, hindering commercialization. A simulation study is performed using a lead-free, eco-friendly ITO/WS2/MASnI3/NiO/Au PSC structure using SCAPS-1D software. This structure utilizes tungsten disulfide (WS2) as an electron transport layer (ETL), methylammonium tin iodide (MASnI3) as an absorber layer, and nickel oxide (NiO) as a hole transport layer (HTL). The study found the optimized bandgap for the WS2 layer to be 1.6 eV, with an optimized thickness of 0.5 µm. The highest permissible defect density in the WS2 interface is 1015 cm−3, while in the WS2/MASnI3 interface, it is lower at 1011 cm−3. High defect density reduces the photo conversion efficiency (PCE) of the PSCs. The simulated PSC structure has a lower activation energy of 1.08 eV, indicating an interface recombination center. The optimized device achieved a PSC efficiency of 28.15 %, a VOC value of 0.96 V, and a fill factor (FF) of 83.36%. Notably, the PCE increased to 28.58% at a lower temperature of 280 K. This breakthrough underscores the potential of WS2 as an efficient ETL in eco-friendly PSCs for non-toxic renewable energy solutions.