Potential-induced degradation of crystalline silicon photovoltaic modules with polycarbonate cover

We investigated the potential-induced degradation (PID) of crystalline silicon (c-Si) photovoltaic (PV) modules with polycarbonate cover using both conventional p-type and n-type front-emitter (FE) solar cells. For p-type c-Si PV modules, EVA/glass configuration showed the most severe degradation due to shunting-type PID (PID-s), with significant losses in open-circuit voltage (Voc) and fill factor (FF) due to decreased shunt resistance (Rsh), whereas the modules with polycarbonate (PC) covers showed high PID resistance. In n-type FE c-Si PV modules, glass-covered modules exhibited faster degradation due to polarization-type PID (PID-p), while PC-covered modules maintained higher stability. The results obtained indicate that PC cover layers significantly enhance PID resistance for both cell types and both two types of PID with different mechanisms. Proper selection of cover materials can thus improve the reliability of c-Si PV modules under high-voltage stress.