A silicon solar cell is provided, including a first silicon layer that absorbing sunlight, a first layer of a structure of photonic crystals formed on the first silicon layer, and a second silicon layer formed on the first layer of a structure of photonic crystals and absorbing sunlight, wherein the first silicon layer and the second silicon layer absorb sunlight at different wavelengths and the first layer of structure of photonic crystals selectively reflects light of a wavelength absorbed by the second silicon layer.