Reviewed by Lexie CornerJan 30 2025
Researchers at the University of Tsukuba investigated the internal state of Ruddlesden-Popper (RP) tin-based perovskite solar cells using electron spin resonance to improve efficiency and durability. Their findings were published in npj Flexible Electronics.
Perovskite solar cells have gained attention as a next-generation photovoltaic technology due to their high efficiency, flexibility, and printability. However, conventional perovskites contain lead, raising environmental concerns due to toxicity.
To address this issue, researchers have explored tin-based perovskites as a more environmentally friendly alternative. However, tin's susceptibility to oxidation reduces efficiency and stability compared to lead-based counterparts.
One approach to improving tin perovskite durability involves incorporating large organic cations into the crystal structure, forming a two-dimensional layered arrangement known as RP tin-based perovskites. While this strategy has demonstrated enhanced stability, the underlying mechanisms responsible for performance improvements remain unclear.
To investigate these mechanisms, researchers used electron spin resonance to analyze the internal state of an RP perovskite solar cell at the microscopic level during operation.
Perovskite solar cells consist of electron and hole transport layers surrounding the perovskite crystal. In the absence of light, holes diffused from the hole transport layer into the RP perovskite, creating an energy barrier at the interface between the two materials. This barrier suppressed electron backflow, enhancing device performance.
Under illumination, high-energy electrons generated by short-wavelength light, such as ultraviolet radiation, migrated from the RP tin-based perovskite into the hole transport layer. This electron transfer further increased the interfacial energy barrier, leading to improved efficiency.
A detailed understanding of these performance-enhancing mechanisms is critical for the development of high-efficiency, long-lasting perovskite solar cells and will guide future advancements in photovoltaic technology.
The study was supported by the Japan Science and Technology Agency MIRAI (Grants No. JPMJMI20C5, JPMJMI22C1, and JPMJMI22E2); the New Energy and Technology Development Organization, Green Innovation; the Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research (KAKENHI) (Grant No. 24K01325); the University of Tsukuba, Organization for the Promotion of Strategic Research Initiatives; and JST SPRING (Grant No. JPMJSP2124).
Journal Reference:
Chen, Y., et al. (2025). Operando spin observation elucidating performance-improvement mechanisms during operation of Ruddlesden–Popper Sn-based perovskite solar cells. npj Flexible Electronics. doi.org/10.1038/s41528-024-00376-2.