Optoelectronic proprieties improvement of multicrystalline silicon by Alumina Nanoparticles and silicon nitride

In this paper, we compared the effects of alumina nanoparticles and silicon nitride layer deposited on multi-crystalline silicon separately of structure, optic, and optoelectronic properties, to achieve excellent surface. Alumina nanoparticles -covered mc-Si immersion in HF/H2O2/HNO3 and porous silicon covered with silicon nitride structure are the key factors to achieving a high electronic quality of multi-crystalline silicon. Consequently, the surface reflectivity decreases from 35% to 2% for alumina nanoparticles/PS and to 5% for silicon nitride/PS in the wavelength range of 250–1200 nm. Meanwhile, the minority carrier diffusion length increases from 2 µm to 300 µm for PS combined with SiNx and to 100 µm for alumina nanoparticles/PS. Furthermore, the Two-Dimensional Produced Current measurement shows a significant enhancement compared to bare mc-Si (2.8 nA), reaching a maximum of 34 nA for alumina nanoparticles/PS and 66 nA for PS combined with SiN. These results indicate that multi-crystalline silicon surface passivation using aluminum/PS or PS combined with SiNx is an effective approach to enhancing the electronic quality of mc-Si wafers, thereby improving the efficiency of mc-Si-based solar cells.