Fabrication and photovoltaic property of ordered macroporous silicon

Wafer-scale highly ordered macroporous silicon (macro-PSi) has been fabricated by the combination of lithography and metal-catalyzed Si etching in hydrofluoric acid. The periodicity and dimensions of the pores can be controlled by the lithography and the etching conditions. Significantly, this catalytic etching method is capable of creating uniform pores on Si substrates of any type of conductivity. Photovoltaic application results showed that the as-prepared macro-PSi samples are photoactive, and became more effective in solar energy conversion via surface modification with metal particles. The present fabrication method of macroporous Si structures could open potential applications in solar cells, photonic crystals, sensors, and batteries.