Amplified spontaneous emission in semiconductor-nanocrystal/synthetic-opal composites: Optical-gain enhancement via a photonic crystal pseudogap

Novel materials consisting of titania sol-gel/CdSe- or PbSe-nanocrystal (NC) nanocomposites infiltrated into polystyrene opal photonic crystals (PCs) are presented (see Figure). These composites exhibit efficient amplified spontaneous emission at decreased thresholds relative to the reference sol-gel/NC materials, despite the lower volume loading of NCs in the photonic structures. This work points toward tunable NC/PC lasers that can benefit from the easy manipulation of NC emission properties and PC band positions.