Mixed-phase p-type silicon oxide containing silicon nanocrystals and its role in thin-film silicon solar cells

Lower absorption, lower refractive index, and tunable resistance are three advantages of amorphous silicon oxide containing nanocrystalline silicon grains (nc-SiOx) compared to microcrystalline silicon (mu c-Si), when used as a p-type layer in mu c-Si thin-film solar cells. We show that p-nc-SiOx with its particular nanostructure increases mu c-Si cell efficiency by reducing reflection and parasitic absorption losses depending on the roughness of the front electrode. Furthermore, we demonstrate that the p-nc-SiOx reduces the detrimental effects of the roughness on the electrical characteristics, and significantly increases mu c-Si and Micromorph cell efficiency on substrates until now considered too rough for thin-film silicon solar cells. (C) 2010 American Institute of Physics. [doi:10.1063/1.3517492]