Investigation of photoelectrochemical etching of textured silicon in solar cells

Light trapping is an important method to increase the efficiency of solar cells. In this work, we study the combined effects of photoelectrochemical etching and texturing to enhance light trapping. Porous silicon (PSi) as an antireflection coating is fabricated on the surface of a textured silicon layer by photoelectrochemical etching. The effects of different electrochemical conditions such as acidic solutions, illumination, current densities, and etching time on the solar cell parameters and surface reflectance from the silicon are evaluated. Our results indicate that the average reflectance of the surface is lower when electrochemical etching is combined with texturing and the PSi thus formed can serve as an antireflection layer in single-crystal silicon solar cells. Our SEM results acquired from samples prepared under different conditions show that the morphology of the textured surface can be improved by electrochemical etching.