Pathways to High-Efficiency Perovskite-Organic Tandem Solar Cells

Perovskite-organic tandem solar cells (POTSCs) have emerged as a promising strategy to transcend the thermodynamic Shockley-Queisser limit of single-junction devices. This architecture uniquely combines the exceptional tunability of wide-bandgap (WBG) perovskite front cells with narrow-bandgap (NBG) organic rear cells. In this review, we systematically examine the critical challenges and advancements in POTSCs. For the WBG perovskite subcells, we focus on composition engineering for precise bandgap tuning, the underlying thermodynamic and kinetic mechanisms of phase segregation, energy loss pathways resulting from non-radiative recombination, and interface regulation strategies. Regarding the organic subcells, we highlight the necessity of exact bandgap matching and summarize molecular design strategies aimed at developing highly efficient NBG materials. Finally, we discuss the tandem architecture potential for achieving high power conversion efficiencies and synergistic stability. In this synergistic configuration, the WBG perovskite layer acts as a natural UV filter to protect the organic materials from high-energy photons, while the moisture-insensitive organic layer provides a barrier to shield the perovskite from water and oxygen erosion. By dissecting these key aspects, this review aims to provide a comprehensive roadmap for propelling POTSC efficiencies beyond the 30% milestone.