Stripes of 2D photonic crystal obtained from macroporous silicon

A novel technological process has been developed to pattern macroporous silicon. In contrast to the existing process, the technique proposed here does not require pore filling and planarisation of the surface, thanks to the use of photolithography on the backside of the wafer. Stripes with vertical walls of 2D photonic crystals were prepared from macroporous silicon and characterized by FTIR microscopy. Interesting by-products of the developed process are silica microtubes, which are organized in a periodic “lattice” and possess strong photoluminescence.