Enhanced photoluminescence and photonic bandgap modification from composite photonic crystals of macroporous silicon and nanocrystalline PbS thin films

We report on the fabrication of composite photonic crystals (PCs) of macroporous silicon and PbS thin films and about their passive and active optical properties. We have measured a redshift in the composite PC photonic stopbands relative to those of the PC substrate. In addition, we have measured a high extraction efficiency of the photoluminescence from the embedded PbS films due to band-edge singularities and slow-light modes of a defect-free two-dimensional composite PC. The peak extraction efficiency has been found to be six times larger than that of planar unpatterned PbS films.