Progress in highly efficient and stable dye-sensitized solar cells: state-of-the-art materials and device fabrication

Dye-sensitized solar cells (DSSCs) represent a leading class of third-generation photovoltaic technologies, distinguished by their low-cost processing, mechanical flexibility, semi-transparency, and exceptional efficiency under low-light and indoor illumination. Since their inception in 1991, continuous advancements in molecular sensitizers, redox electrolytes, and electrode architectures have raised device efficiencies to over 15% under AM 1.5G sunlight and over 40% under indoor lighting. These improvements stem from synergistic progress in light-harvesting design, charge-transport engineering, and interface optimization. Recent innovations—such as broadened-absorption sensitizers, cobalt- and copper-based redox mediators, and nanostructured counter electrodes—have significantly enhanced catalytic activity, reduced charge-transfer resistance, and improved long-term stability. Engineering strategies such as tandem device configurations, quasi-solid/solid-state electrolytes, and advanced encapsulation techniques have further accelerated the transition of DSSCs toward commercial relevance. Indoor DSSCs, which benefit from ideal spectral matching to artificial light, have emerged as prime candidates for powering autonomous IoT and low-power electronics. Despite these achievements, challenges remain in balancing efficiency, durability, and scalable manufacturing. This review comprehensively summarizes recent progress in high-efficiency and stable DSSC technologies, covering operating principles, performance-governing parameters, state-of-the-art materials, device architectures, and strategies for pushing performance toward theoretical limits. Future opportunities and commercialization prospects are also discussed to guide the next stage of DSSCs development.