Figure 7.

Photocurrent for four typical porous Si samples. Two of the samples (full rounds and diamonds) are impregnated with eumelanin and two (empty triangles and squares) are as prepared. The sample labeled ‘impregnated PSi 2’ shows very low photocurrent intensity due to the unoptimized contact fabrication process. The wavelength reported in the abscissa is the cutoff wavelength of the low-pass filters we used.