The Study of Silane-Free SiCxNy Film for Crystalline Silicon Solar Cells

Abstract

We deposited plasma-enhanced chemical vapor deposition silicon carbon nitride antireflection coating and passivation layers using a silane-free process. We used a solid polymer source developed at SiXtron Advanced Materials to eliminate the storage and handling of dangerous pyrophoric silane gas. We used ammonia flow rate as a control for the chemical and optical properties in the silane-free process. As flow rate increases, the carbon content, refractive index, extinction coefficient, and surface charge density of the film decrease. At an ammonia flow rate of 3000 sccm, which is similar to the conventional , the extinction coefficients for the two films were similar. This led to an emitter dark saturation current density of for the two films on emitters. However, a stack passivation of on an emitter resulted in an emitter dark saturation current density of , which is enough to provide a good surface passivation for high efficiency solar cells. An energy conversion efficiency of 17.4% was obtained for a textured Czochralski screen-printed solar cell with this stack passivation. For a nontextured multicrystalline silicon, with only and a emitter, we obtained 14.9% efficiency.