Spectral properties of Eu3+ and rhodamine 6G emitters in opal photonic crystal films

Анотація

The Eu³⁺ photoluminescence spectra measured on the infiltrated opal film areas with visible structural defects are found to be independent of the observation angle and essentially different from the Eu³⁺ spectrum obtained on the visually homogeneous film areas. This is explained in the framework of the multi-site occupation model where the defect boundaries facilitate the stabilization of specific coordination environment of the Eu³⁺ ions. A sandwich-like geometry of opal films is found to provide optical feedback for rhodamine 6G, resulting in significant spectral modification and intensity enhancement. It is shown that these changes are not caused by concentration or thermal gradients.