Functionalized Organic/Polymeric Materials for Perovskite and Organic Solar Cells

ConspectusPerovskite solar cells (pero-SCs) and organic solar cells (OSCs), owing to their solution processability, lightweight form factors, and exceptional mechanical flexibility, have emerged as leading contenders to complement silicon photovoltaics in distributed energy systems. In recent years, rapid progress has pushed the power conversion efficiencies of rigid laboratory-scale pero-SCs beyond 27% and OSCs above 21%. Yet, translating these achievements into practical deployment requires simultaneous advances in flexibility, large-area manufacturability, and long-term operational stability. The chemically programmable nature of organic and polymeric materials provides a powerful platform for addressing these challenges. Their tunable molecular structures enable the rational design of functional motifs tailored to the specific needs of different thin-film layers, offering “function-on-demand” capabilities. Such functionalized materials can be engineered to serve as key components in printed flexible transparent electrodes, charge-transport layers, and active layers. By introducing well-defined redox-active units, dynamically cross-linkable groups, self-assembling cores, and moieties that modulate solution viscosity and aggregation behavior, researchers can simultaneously improve mechanical robustness, film uniformity, interfacial energetics, and environmental stability. In this Account, we highlight recent advances in achieving stable, flexible, and large-area pero-SCs and OSCs through use of functionalized organic and polymeric materials, with emphasis on key contributions from our group. We summarize the underlying design principles, elucidate structure–property–performance correlations in representative material systems, and illustrate how functionally tailored molecules can bridge the gap between molecular-level design and device-level performance. Finally, we offer our perspective on remaining challenges and future research directions toward practical implementation of flexible and scalable perovskite and organic photovoltaics.