Reducing UV induced degradation losses of solar modules with c-Si solar cells featuring dielectric passivation layers

We report on the effect of UJV irradiation on solar modules featuring crystalline silicon solar cells with various types of passivation layers and encapsulation polymers with varying UJV transparency. Our results reveal that solar modules featuring cells with an aluminum oxide/p+-type silicon passivation interface on the illuminated side are stable within 1500 h UJV exposure. Modules featuring bifacial back junction cells with a silicon nitride/n+-type silicon passivation interface in combination with an ethylene vinyl acetate encapsulation with enhanced UJV transparency degrade up to 15% in module power due to UJV illumination. We ascribe the UJV degradation to an increase in surface recombination. Analytical modeling the degradation of the surface passivation interface indicates that photons with an energy similar to the Si-H bond energy are responsible for UJV degradation.