Researchers from UNSW have developed a model linking UV-induced degradation in TOPCon solar cells to hydrogen transport, charge trapping, and structural changes in the passivation stack. Thicker aluminum oxide layers improve UV resilience by limiting hydrogen migration. The study conducted on TOPCon cells showed a complex interaction between chemical degradation and temporary enhancement in field-effect passivation. High-energy UV photons break Si-H bonds in the SiNx capping layer, releasing mobile hydrogen that degrades chemical passivation. Thicker 7 nm AlOx layers act as a more effective barrier to hydrogen transport, improving UVID resilience. Researchers have identified new failure modes and degradation mechanisms in TOPCon solar modules, including the impact of soldering flux, contact corrosion, and sodium-induced degradation. The research also highlights the vulnerability of TOPCon solar cells to various forms of degradation under different conditions. The study provides design guidance for more UV-robust passivation stacks and improved testing protocols, as presented in a paper published in Solar Energy Materials and Solar Cells.