UV radiation hardness of photovoltaic modules featuring crystalline Si solar cells with AlOx/p+‐type Si and SiNy/n+‐type Si interfaces

We report on the UV radiation hardness of photovoltaic modules with bifacial n‐type Passivated Emitter and Rear Totally diffused crystalline Si cells that are embedded in an encapsulation polymer with enhanced UV transparency. Modules with front junction cells featuring an AlO x /p + ‐type Si passivation interface at the illuminated side are stable for a UV irradiation dose of 598 kWh m −2 . In contrast, irradiating modules with back junction cells featuring an a‐SiN y /n + ‐type Si passivation interface at the illuminated side reduces the output power by 15%. The quantum efficiency of the a‐SiN y ‐passivated module degrades in the spectral range between 300 and 1000 nm, which we ascribe to a degradation of the surface passivation. Modeling the experimental data shows that photons with an energy above 3.4 eV contribute to the degradation effect and enhance the front surface recombination current density by a factor of 15.