Improved SiNx∶H passivation for industrial emitter-wrap-through multicrystalline silicon solar cells

Silicon nitride deposited by direct plasma chemical vapor deposition (D-PECVD) and remote plasma chemical vapor deposition (R-PECVD) is tested in terms of minority carrier lifetime. Data shows that the minority carrier lifetime is improved with D-PECVD SiNx compared to RPCVD SiNx. Emitter wrap through (EWT) solar cell fabrication showed similar improvements in short-circuit current density Jsc and open-circuit voltage Voc. The best efficiency obtained on non-textured standard industrial multicrystalline silicon wafers is 16.9% with Jsc = 36.7 mA/cm², Voc = 609 mV and fill factor FF = 75.4%. PC-1D fitting of the internal quantum efficiency (IQE) data shows front surface recombination velocity in the range of ~9e4 cm/s. This efficiency can further be improved by incorporating texturing in the process steps.