Photonic Properties of Inverse Opals Fabricated from Lanthanide-Doped LaPO4 Nanocrystals

A new method for the preparation of rare-earth doped inverse opal materials is reported. Template structures consisting of ordered stacks of PMMA-spheres were infiltrated with colloidal solutions of luminescent LaPO4:Ln (Ln= Tb3+, Eu3+) nanocrystals containing a small amount of prehydrolyzed tetramethoxysilane as binder. After calcination of the PMMA-template, light-emitting photonic materials with inverse opal structure are obtained. Under UV-excitation the materials display the characteristic luminescence line emission of the lanthanide component. We show that by adjusting the diameter of the PMMA-spheres of the template the photonic band structure of the material can be controlled in a way that modifies the lanthanide luminescence.