Unveiling the potential of lead-free Cs2AgBiBr6 (CABB) perovskite for solar cell application

The remarkable structural stability and optoelectronic properties of Cs2AgBiBr6 (CABB) material have positioned it as a highly appealing candidate for the solar cell application. The research focused on modeling and examination of perovskite solar cells utilizing Cs2AgBiBr6 as the active material, incorporating various electron transport layers (ETL) and hole transport layers (HTL). The device structure comprised of ITO/ZnO:Al/ZnO/Cs2AgBiBr6/Cu2O/Au. This optimized device, shows Voc = 1.67 V, Jsc = 15.52 mA/cm2, fill factor (FF) = 71.32 %, and conversion efficiency = 18.5 %. Active layer defects and trap charges at the interface of the CABB layer can trap photo generated electrons and holes, permitting higher carrier recombination. That reduces both open circuit voltage and short circuit current density. The conversion efficiency deteriorates from 18.5 % to 2.65 % when the defect density increases from 1 × 1010/cm3 from 1 × 1016/cm3. Also trap charges and multiple trap charges play a vital role in the performance of the CABB solar cell.