Ultraviolet-induced degradation mechanisms and mitigation strategies for silicon solar cells

Ultraviolet-induced degradation (UVID) is a reliability concern for high-efficiency crystalline silicon photovoltaics. The understanding of its mechanisms is important as technologies evolve beyond passivated emitter and rear contact (PERC) toward passivating-contact, back-contact, tandem, and space applications. This review discusses UVID in silicon solar cell structures including PERC, TOPCon (tunnel oxide passivated contact), HJT (heterojunction technology), and BC (back contact) technologies. We analyze the coupled interfacial and bulk degradation pathways associated with ultraviolet illumination. Recent advances in mitigation strategies are evaluated, spanning passivation engineering, doping design, optical spectral management, and post-exposure recovery treatments. Reliability considerations in next-generation back-contact structures, silicon-based tandem cells, and extreme operating environments such as space under AM0 conditions are highlighted. By linking mechanistic insights with technology-relevant design strategies, we outline research directions required to ensure that efficiency gains in modern silicon photovoltaics are accompanied by long-term stability.