ETM ENGINEERING AND PERFORMANCE OPTIMIZATION OF LEAD-FREE K₂GeBr₆ PEROVSKITE SOLAR CELLS

Abstract

In this work, we examine a lead-free double perovskite absorber, K₂GeBr₆, in device architecture FTO/ETM/K₂GeBr₆/WoO₃/Au via SCAPS-1D simulations. A systematic comparison was conducted among three different electron transport materials (ETMs), TiO₂, SnO₂, and WO₃, with WoO₃ as the hole transport material. The results indicate that TiO₂ is the best interface with K₂GeBr₆ due to device electrical parameters such as highest efficiency of 26.8%, Voc=1.46 V, Jsc=24.9 mA/cm², and FF=73.5%. Although SnO₂ and WO₃ shows promising characteristics, such as greater recombination losses with compromised performance. The results conform TiO₂ as the most efficient ETM of K₂GeBr₆ and confer its viability as the sustainable, nontoxic absorber material in the design of the future environmentally friendly perovskite.