The length scales in nanometer range for both inorganic and organic materials have unique physical responses. The opto-electronic properties of metals [1] and semiconductors [2] strongly depend on their size, material used and crystalline shape in the nanometer size regime. New synthetic approaches have been applied to fabricate series of monodisperse nanometer size crystals, known as nanocrystals or nanoparticles (NPs). In particular, semiconductor NPs [3] have attracted tremendous attention due to their unique physical properties, which originate from the surface atoms of nanoscale objects and from the size quantization effect [4]. Group II–VI semiconductor NPs are currently of great technological interest as emitting materials for thin film electroluminescence devices [5], [6] and as optical amplifier media for telecommunication networks [7], [8], because of their strong bandgap luminescence. The incorporation of luminescent semiconductor NPs into photonic crystals [9] has also obtained substantial attention recently as a novel light source with controllable spontaneous emission. Thiol-capped semiconductor NPs with size-dependent luminescence in the visible spectral region have been synthesized in aqueous colloidal solutions [10] and used for fabrication of light-emitting diodes (LEDs) [11], and for impregnation of colloidal photonic crystals [12].