Effects of Progressive SiNx Films on the Performance of Polycrystalline Silicon Solar Cells

In order to improving the conversion efficiency of polycrystalline silicon solar cells, progressive SiNx thin films were deposited on the surface via Roth&Rau plasma-enhanced chemical vapor deposition method. The effects of progressive SiNx thin films, such as surface passivation, anti-reflection, and electrical performance were systematically investigated. Compared with monolayer films, progressive SiNx thin films have better anti-reflective properties in the wavelength range of 300-500 nm, resulting in improvement of the short wavelength absorption of the crystalline silicon solar cells. Moreover, the bottom of progressive SiNx thin films with high refractive index enhances the surface passivation. Thus, higher open-circuit voltage and fill factor could be obtained by this technique.