Potential applications of porous silicon in photovoltaics

Porous Si formed on crystalline Si wafers using electrochemical etching exhibits photoluminescent and electroluminescent properties. The authors report on the results of their investigation of using porous Si as surface texturing to enhance the performance of crystalline silicon photovoltaic solar cells. Unlike conventional KOH-based texture etching, which can only be used on [100]-oriented single-crystalline Si substrates, porous Si can be etched onto Si surfaces of any crystallographic orientation and onto polycrystalline or microcrystalline Si surfaces. A porous-Si-covered single-crystal Si wafer showed an integrated reflectance of only 1.4% at a wavelength of 500 nm. The reflectance of a porous-Si-covered polycrystalline Si was found to be comparable to other much more complicated texturing methods