Effect of substrate temperature on the plasma texturing process of c-Si wafers for black silicon solar cells

We report on a study of the effect of the substrate temperature on the formation of black silicon on c-Si wafers and consequently on the reduction of the wafer surface diffuse reflectance. We observed that lower substrate temperatures enhance the texturing processes producing completely black silicon surfaces. The optimized substrate temperature (2.5 °C) used during the plasma process has resulted in the formation of well-defined pyramid-like structures as is done by wet processes. Moreover, the textured c-Si wafers have very low diffuse reflectance values, as low as 3%, which are much lower than those values obtained using wet texturing processes based on KOH and NaOH solutions (which are in the range of 12–14%).