Emission pattern of planar CdTe nanocrystal light source coated by two-dimensional Langmuir-Blodgett photonic crystal

Modification of the emission pattern from an optically thin film of CdTe nanocrystals has been achieved by deposition of a monolayer of silica spheres crystallized in a hexagonal lattice by the Langmuir-Blodgett method. The emission band of coated samples shifts to shorter wavelengths, the emission intensity decreases and the emission directionality diagram becomes essentially wider compared to that of the bare emitting film. In the spectral range of the overlap of the emission band and the photonic bandgap of the two-dimensional photonic crystal, the emission intensity increases towards the direction of the photonic bandgap.