Scanning electron microscopy micrographs of n-type silicon carbide (SiC) anodized in HF solution showed a highly porous layer having structures with dimensions of about 50 nm. The capacitance of the porous electrodes revealed a huge surface area. The photocurrent quantum yield of a porous SiC/electrolyte diode is spectacularly enhanced with respect to that of a flat diode for light absorbed in the indirect-bandgap and for sub-bandgap light.