The minimization of the re?ection of Si substrates is analyzed for the use of photovoltaic applications. Antire?ection coatings consisted of both bulk and nanostructured thin ?lm SiO2 and ITO over a broad spectral range of 400 to 1000nm are optimized. The genetic algorithm and the transfer matrix method are applied and the thickness of layer varied, where refractive index and number of layer ?xed for ITO, SiO2 layers. Optimization is performed by nanostructure with the order of low-n SiO2 and low-n ITO and the second order is low-n SiO2 and high-n ITO. The results are compared to their bulk forms and bare Silicon. Angle- and wavelength-averaged re?ection coe?cient for a periodic six-layer thin ?lm anti-re?ection coatings (ARCs) consisting low-n nanoporous SiO2 and high-n nanoporous ITO on silicon substrate reduced to 30% and is reported as the suitable structure of silicon solar cells.