SiOyNx/SiNx Stack Anti-reflection Coating with PID-resistance for Crystalline Silicon Solar Cells

Anti-reflection coating (ARC) on crystalline silicon solar cell plays an important role in preventingpotential induced degradation (PID). In this work, we present a dual-layer ARC for increased resistance to potential induced degradation. By introducing a thin SiOyNx layer between the SiNx layer and the Si substrate, animproved chemical surface passivationwas obtained. A 0.1% absolute gainin conversion efficiencywas obtained compared to the result of single SiNx coated multi-crystalline solar cell. In addition, the SiOyNx/SiNx stack increased the resistance to PID, showing a nearly zero degradation in shunt resistance (Rsh) after a 24 hours PID-sensitivity test, performedat high voltage (-1000 V) and 60oC. In comparison, the Rsh of multi-crystalline silicon solar cellscoated with singleSiNx layer degraded by 30%. Capacitance-voltageand leakage current measurements indicate that the main factor for PID-sensitivity was the dielectric layer, especially the charge trappingcenters in the dielectric. The tocharge trapping center degrades both the quality of the dielectric/substrate interface and increases the leakage current.