Control over the distribution of luminescent impurities inside opal photonic crystals

• Different ways to control the distribution of luminescent impurities inside opal photonic crystals are considered.
• Europium (III) organic complex HEuEDTA and CdSe quantum dots were incorporated inside bulk and thin film synthetic opals.
• Opals with the uniform HEuEDTA luminescent layer on the surface of SiO2 microspheres have been obtained.
• Opals with the special location of quantum dots around contact points between microspheres have been obtained also.
• Different electron microscopy methods were used to check the luminescent components distribution.

The work is focused on the problem of control over the distribution of emitting centers inside photonic crystals. Two ways of luminescent impurity incorporation into synthetic silica opals are considered. First is based on the infiltration of the opal with a water solution of organic complexes (HEuEDTA) and leads to a formation of a uniform luminescent layer on the surface of silica microspheres. The other involves the infiltration of the structure with a heptane solution of CdSe quantum dots leading to the localization of the luminescent component around contact points between microspheres. Thus two different types of strongly ordered distribution of luminescent component inside opal can be obtained. Corresponding samples were prepared and their optical properties are discussed.