Modification of emission of CdTe nanocrystals by the local field of Langmuir-Blodgett colloidal photonic crystals

A light source on the surface of a slab of 2 + 1 -dimensional photonic crystal has been prepared by the Langmuir-Blodgett deposition of a colloidal crystal on top of a thin film containing CdTe nanocrystals. The directional enhancement of the light emission intensity in the spectral range of the photonic bandgap has been revealed through the comparative examination of the angle-resolved transmission, diffraction, and photoluminescence spectra of the prepared structures. Changes in the emission spectrum have been tentatively explained in terms of the acceleration of the radiative recombination due to the increase in the local field strength at photonic bandgap resonance and changes in the emission diagram-as arising from the wavelength dependence of the topology of the local field pattern.