Influence of bowl-like nanostructures on the efficiency and module power of black silicon solar cells

Abstract

In this work, black multi-crystal silicon (Mc-Si) solar cells with bowl-like nanotextured surfaces were successfully fabricated by a metal-assisted chemical etching (MACE) method. Defect removal etching processes of various durations were used to form bowl-like nanostructures of three sizes on the wafer surface. Overall, a low depth and large diameter of bowl-like structure in nanotextured surfaces is demonstrated to be helpful in reducing surface recombination and improving the cell and module performance. The average cell module power of the bowl-like nanotextured surfaces with an average bowl diameter 680 nm is clearly higher by 1.51 W, 1.46 W, and 1.26 W than for nanotextured surfaces with bowl diameter 460 nm in the 18.8%, 18.9%, and 19.0% efficiency bins. A maximum cell efficiency of 19.17% and module power of 279.74 W were obtained using our MACE process in an industrial mass production line. The techniques presented in this paper can be used for the mass production of diamond wire sawing Mc-Si solar cells and meet the requirements of high efficiency and low cost in the photovoltaic industry.