| The double perovskite Cs2SnI6 has notable optical and electrical characteristics, rendering it a highly prospective candidate for deployment as the absorber layer in perovskite solar cells (PSC). We simulated the performance of PSCs using lead-free Cs2SnI6 double perovskite absorber layers and graphene derivatives (Go and rGO) hole transport layers (HTLs), and demonstrate that rGO offers a remarkable hole extraction property with minimal interfacial recombination compared to GO. PSCs utilizing rGO as the HTL material achieved a power conversion efficiency of 19.04%, while those employing GO HTL attained only 16.7%. The superior performance of rGO is attributed to greater charge carrier mobility of rGO and its favourable energy level alignment with the double perovskite absorber layer. In contrast, the mismatch in the charge transport properties between the absorber layer and the GO HTL resulted in poor performance. Our study showcases the potential of using graphene derivative-based HTLs for realizing lead-free PSCs. |
