A new method was developed for making a porous silicon layer as in anti-reflective coating on the top of crystalline silicon solar cells. The porous silicon layer was formed in a mixed solution of H2O2 and HF by using screen-printed Ag front electrodes as the catalyst. With the help of the catalytic effect, porous silicon layers were formed by treatment in a solution chemically milder than conventional solutions. The multi-crystalline silicon solar cell covered with the porous silicon layer showed a surface reflectance below 15% in a wavelength region of 400-800 nm. (c) 2005 Elsevier B.V. All rights reserved.