Simulation and optimization of lead-free CH3NH3SnI3 perovskite solar cells using SCAPS-1D

• Lead-free perovskite solar cell (PSC) using CH₃NH₃SnI₃ as the absorber layer, due to low band gap, high absorption coefficient and non-toxicity. • The simulations were conducted using the SCAPS-1D program with the AM 1.5 G spectrum to evaluate the PSC’s performance. • The device structure includes FTO/TiO 2 /IDL/CH 3 NH 3 SnI 3 /Carbon, with TiO 2 serving as the electron transport layer (ETL). • The influence of absorber layer thickness, defect density, doping concentration, operating temperature, and various back contacts are studied. • The optimized PSC achieves a PCE of 22.23 %, VOC of 0.886 V, a JSC of 30.68 mA/cm2, and a FF of 81.58 % at 300 K. Recent advances in photovoltaic technology have made perovskite solar cells attractive prospects for future energy solutions. However, the presence of lead (Pb) in many perovskite materials causes environmental and health problems, limiting their practical utility. This work investigates the possibility of lead-free perovskite solar cells (PSCs) with CH 3 NH 3 SnI 3 as the absorber layer. CH 3 NH 3 SnI 3 is chosen for its advantageous qualities such as non-toxicity, good visible light absorption, and smaller band gap. The SCAPS-1D modeling tool was used to model these cells performance in the AM 1.5 G solar spectrum. The study looks at how varying absorber layer thicknesses, doping levels, defect densities, operating temperatures, back contact materials,series and shunt resistance affect the performance of the solar cell. The simulated device structure is FTO/TiO 2 /IDL/CH 3 NH 3 SnI 3 /Carbon, with TiO 2 as the electron transport layer (ETL) and CH 3 NH 3 SnI 3 as the absorber layer. At 300 K, the device exhibits an open-circuit voltage (Voc) = 0.886 V, a fill factor (FF) = 81.58 %, a short-circuit current density (Jsc) = 30.68 mA/cm 2 , and a power conversion efficiency (PCE) = 22.23 %.