Performance enhancement of mc-Si solar cells due to synergetic effect of plasma texturization and SiNx:H AR coating

The present paper discusses the plausible physical processes dominant during plasma texturization of multicrystalline silicon (mc-Si) wafers, deposition of silicon nitride (SiNx) antireflection (AR) coating and firing of contacts through it. During plasma texturization, it is observed that by using low RF power density and loading wafers on the ground electrode, the texturization process is dominated by chemical etching. The resulting surface of the wafer shows low-reflectivity (<10% in wavelength range 350–800 nm) and low-defect density leading to improved minority carrier lifetime. It is postulated that plasma-etched nanoscale structures accelerate the migration of hydrogen released during firing of contacts. As a result of these physical processes, an improvement up to ~2.4% in absolute efficiency of large area (~149 cm2) multicrystalline silicon solar cells has been achieved.