Rapid fabrication of antireflective pyramid structure on polystyrene film used as protective layer of solar cell

A promising strategy is proposed for facilely and successively replicating randomly arranged pyramids on an etched silicon wafer to polystyrene (PS) surface. First, a nickel mold insert with negative pyramids is fabricated via combining electroless plating and subsequent electroplating with an etched silicon wafer as atemplate. Then, by using microinjection compression molding with the nickel mold insert as a template, the pyramids on the insert are accurately transcribed to the PS surface. The pyramids on the PS replica surface have the hemlines of about 1-7 mu m and heights of about 1-4 mu m. The PS replica surface exhibits a reflectance of about 5% in the wavelength range of 400-900 nm and an enhanced transmittance. That is, it exhibits an enhanced light trapping effect, which originates from a combination of staggered arrangement and dense distribution of the pyramids with arc-shaped top and different sizes. Especially, a thin film solar cell covered with the PS replica exhibits increased power conversion efficiency enhancement of up to 7.9% under normal incidence comparing to that covered with the PS counterpart. The solar cell covered with the PS replica also shows an excellent photovoltaic performance over a wide range of incident angles (0-70). The proposed fast and efficient replication strategy can be an excellent candidate for developing antireflective protective layers without complicated procedures and expensive materials.