Silane-free PECVD silicon carbon nitride (SiCxNy) passivation and anti-reflection coatings for high efficiency silicon solar cells

Industrialized silicon solar cells were fabricated using silane-free silicon carbon nitride (SiC_xN_y) film as an antireflection (AR) and surface passivation layer. Sixtron Advanced Materials has developed a gas generation system to deposit the dielectric film that uses a polymeric solid source. Sixtron eliminates the cost and hazards associated with storing and handling pyrophoric silane gas. The electrical and optical properties of the new AR coating layer are investigated and compared to the SiN_x films coated with silane (SiH₄) gas. We tuned the film properties using NH₃ flow rate from previous work. In this work, we further optimized the film properties. As plasma power increases, interface trap density (D_it) and flat band charge (Q_fb) are reduced while refractive index and extinction coefficient remain similar. Screen-printed 149cm² Czochralski (CZ) Si solar cells with SiC_xN_y AR coating layer provides an energy conversion efficiency of 17.2%, which is comparable to that of conventional SiN_x coated solar cells.