Lasers help scientists see solar cells self-heal from UV damage

Researchers at the University of New South Wales (UNSW) have developed a novel laser-based technique using ultraviolet Raman spectroscopy to observe, in real time, how silicon solar cells undergo chemical changes when exposed to ultraviolet (UV) radiation and how they self-heal under visible sunlight. This method allows scientists to non-destructively track molecular vibrations inside working high-efficiency solar cells, revealing that UV exposure damages chemical bonds involving hydrogen, silicon, and boron near the cell surface, weakening the passivation layer and reducing efficiency. Crucially, when exposed again to visible light, these bonds and the cell’s chemical structure recover as hydrogen atoms migrate back and repair broken bonds, confirming that the recovery is a material-level atomic repair rather than just an electrical effect. The findings have important implications for solar panel testing and certification. Current accelerated aging tests using intense UV radiation may overestimate permanent damage because they do not distinguish between reversible and irreversible degradation. The new Raman-based monitoring technique can rapidly detect UV sensitivity without harming the