Abstract

By employing the simple, low-cost and compatibility-process metal-assisted chemical etching (MACE) technique, we prepare the large-size Si nano/microstructures (N/M-Strus) and investigate the photovoltaic applications. Firstly, the ALD-Al2O3-passivated crystalline Si (c-Si) N/M-Strus show the simultaneous realization of the best optical antireflection (the solar averaged reflectance of 1.38%) and electrical passivation (the surface recombination velocity of 44.72 cm/s), which is mainly attributed to the enhanced field effect passivation of the longer-and-thinner Si nanowires together with the complementary antireflection of the Si N/M-Strus at short wavelength and the ALD-Al2O3 at long wavelength. We have further numerically modeled the Al2O3-passivated Si N/M-Strus based solar cell with the high conversion efficiency of 21.04%. Secondly, based on the one-step-MACE multicrystalline Si (mc-Si) N/M-Strus, we report an efficiency (17.63%) of silicon nanostructures based solar cells with a large-size 156×156 mm2, which has surpassed that (17.45%) of traditional-micro-textured ones. Finally, we propose and fabricate a novel p-type c-silicon N/M-Strus based passivated emitter and rear cell (PERC), and successfully achieve an η of 20.0% in a large-size 156×156 mm2 (pseudo-square). The key to success lies in the excellent broadband spectral responses combining the improved short-wavelength responses of the stack SiO2/SiNx passivated Si N/M-Strus based n+-emitter with the extraordinary long-wavelength responses of the stack SiO2/SiNx passivated rear reflector. These screen-printed Si N/M-Strus based solar cells have shown a very promising way to the commercial mass production.

© 2015 Optical Society of America

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