Integrating efficient and tailored perovskite and organic solar cells into performance-improved tandem photovoltaics

Abstract

Over the past decade, the certified power conversion efficiency of champion single-junction perovskite solar cells (PSCs) has exceeded 27%. To overcome the theoretical limitation, various perovskite-based tandem solar cells have emerged. Among them, integrating wide bandgap (WBG) perovskites with organic materials in tandem architectures offers a promising avenue toward higher performance while maintaining the advantages of solution processability, high throughput and compatibility with flexible substrates. Perovskite/organic tandem solar cells (POTSCs) employ a two-subcell structure that maximizes spectral utilization; however, achieving high efficiency requires fine control over energy losses, electrical properties, and optical management. In particular, as the top subcells, WBG PSCs absorb high-energy photons and contribute to a high open-circuit voltage (V_OC), making the minimization of bandgap-V_OC losses—through suppression of defect-induced nonradiative recombination—especially critical. The organic rear cell extends absorption into the near-infrared region, enabling sufficient photon harvesting and current matching between the two subcells. The interconnecting layer (ICL), which provides ohmic contact and facilitates efficient carrier recombination between subcells, also requires continued optimization of both its recombination mechanism and interfacial processes. In this review, we first summarize strategies for improving bulk perovskites and interfacial layers, followed by key design principles for ICLs. We then discuss electrical regulation and optical management in organic subcells. Finally, we outline the current challenges and future perspectives of POTSCs to guide the development of high-performance, scalable and flexible tandem photovoltaic technologies.