D-M-D Plasmonic Anti-Reflector for Next-Generation Thin c-Si Solar Cell Applications

Abstract

In this paper, focus is on the light trapping surface in crystalline silicon (c-Si) solar cells where thinner c-Si wafers are expected to be used by industry to reduce the cost of cell manufacturing. Currently, 180-μm-thick wafers are being used for fabricating c-Si solar cells where textured surface coated with silicon nitride (SiN x ) anti-reflector enhances the light trapping. However, surface texturing process roughens the surface and increases the probability of more surface recombination as the wafer thickness decreases. This paper presents an analytical analysis for the development of plasmonic anti-reflector as an alternative to traditional texturization for next-generation thin c-Si solar cells. The analysis indicates that loss in current generation due to Si wafer thickness reduction up to 100 μm from currently used 180 μm would not be more than 0.5 mA/cm2 if the light trapping structure is excellent. A 100-μm wafer thickness reduction would increase the front escape of light but not more than 1%. PC1D simulation incorporating experimental reflectance from an equivalent 100-μm thin c-Si wafer-based solar cell structure having proposed dielectric-metal-dielectric (D-M-D)-based anti-reflector indicates 1.2–1.3 mA/cm2 current enhancement when compared with a standard SiN x anti-reflector.