Research Projects

Perovskite solar cells (PSCs) have significantly improved their power conversion efficiency (PCE) from 3.8% to over 26% within a decade. The most popular semiconductors of lead halide perovskites (LHPs) AMX₃ have been studied for their high charge carrier mobility, low binding energy of excitons, and strong optical absorption. However, lead-based perovskites suffer from poor stability and toxicity, restricting their commercialization. Several Pb-free Perovskites based on tin, Indium, bismuth, antimony, germanium, silver, and copper have been studied. Sn perovskite has shown the highest promise for next-generation PSCs due to its ideal band gap close to the Shockley-Queisser (SQ) limit. However, Sn-based perovskites suffer more severe stability issues due to the tendency of Sn2+ to form Sn4+, leading to rapid degradation upon exposure to ambient air. An alternate strategy is transmuting two Pb2+ cations to the cation pair of (M+, M3+) to obtain a double perovskite (DP) structure with a formula of A2M+M3+X6. High-throughput screening studies on inorganic halide double perovskites (IHDPs) have been performed, but many show an indirect band gap beyond the SQ limit, which is not favorable for solar cells. The goal is to identify AM+M3+X6 inorganic Lanthanide-based Pb-free double perovskites having superior photovoltaic performance. The study aims to consider a different range of trivalent M3+ elements based on the lanthanide series to create new elemental combinations, specifically considering combinations of (A, M+, M3+, and X) with A = Cs+, Rb+; M+ = In+, Tl+; M3+ = Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, and X = Cl−/Br−.