Double-Perovskite Materials: Possibilities and Reality for a Better Solar Cell Device

Despite the unprecedented certified efficiency of lead-based perovskite solar cells, their incorporation of potentially hazardous lead presents a considerable disadvantage, limiting their commercial feasibility. Halide double perovskites (DPVTs) have emerged as viable alternatives to lead-based perovskites. Nonetheless, obstacles such as inadequate solubility with traditional precursor solvents, an elevated indirect optical bandgap, and heterogeneous structural distributions have been recognized as impediments to their utilization in solar devices. Out of numerous compositions of DPVTs documented in the literature, only a limited number of structures have been effectively incorporated into solar cell systems. Furthermore, there is huge divergence between simulated and actual solar cell efficiencies. Comprehending the essential optoelectronic features and their underlying mechanisms is vital for formulating mitigating methods. This review examines possible DPVTs exhibiting favorable optoelectronic characteristics and photovoltaic metrics. We identify existing problems and innovative mitigation strategies regarding the robustness of DPVT structures, their optoelectronic properties, the simulation of photovoltaic performance, and the laboratory fabrication of DPVTs, while also providing insights into future prospects.