UNSW Sydney researchers have developed a non-destructive monitoring method to observe how ultraviolet radiation damaged high-efficiency silicon solar cells and how those cells naturally recovered under normal sunlight. The team monitored the chemical and material-level changes inside operating cells using ultraviolet Raman spectroscopy without cutting or altering them. The study showed that UV exposure reconfigured chemical bonds near the cell surface, reducing performance while subsequent exposure to visible light restored the original structure as hydrogen atoms migrated back and repaired bonds. The method clarified that recovery occurred at the material level, not only in electrical output. The findings indicated that some UV-related degradation was reversible, raised questions about accelerated ageing tests and suggested the technique could be used for faster, realistic testing and quality control in manufacturing. The research was published in Energy & Environmental Science.