Core–shell silica–rhodamine B nanosphere for synthetic opals: from fluorescence spectral redistribution to sensing

Silica nanospheres were functionalized with rhodamine B and self-assembled into opals. Photoluminescence redistribution and pollutant responsivity were also investigated.

Synthesis and Structural Properties of Nanocomposites Based on Synthetic Opals and Active Dielectrics

This work is devoted to generalize and analyze the previouse results of new photonic-crystalline nanomaterials based on synthetic opals and active dielectrics. Data were characterized by X-ray diffraction and Raman spectroscopy. Active dielectrics infiltrated into the pores of the opal from the melt. The phase structure composition of the infiltrated materials into the pores of the opal matrix were analyzed. The results of x-ray diffraction and Raman spectra allowed to establish the crystal state of active dielectrics in the pores of the opal. The Raman spectra of some opal-active dielectric nanocomposites revealed new bands and changes in band intensities compared to the spectra of single crystals of active dielectrics. Further more, differences in band intensities in the spectra were measured at different spots of the sample‘s surface were observed. The revealed changes were attributed to the formation of new crystalline phases due to the injected dielectrics in opal pores.

Luminescence Spectra of C6H9EuO6 x H2O Doped Synthetic Opals Matrix Containing Bi-Active Dielectrics

This paper presents the results of experimental studies for the luminescence spectral intensity redistribution of opal photonic crystals containing various active dielectrics - Bi12SiO20, opal - Bi2TeO5 and opal - NaBi(MoO4)2 matrix nanocomposites and filled with europium C6H9EuO6 x H2O salt. Ultraviolet excitation was provided by semiconductor laser operating at wavelengths of 400nm and 100 mW average power. An increase in the integral luminescence intensity of the matrix composite opal - Bi12SiO20: Eu3+ was found. The possibility of the participation of bismuth ions as a co-activator and luminescence concentrator also is analyzed. It has been proposed to use opal-Bi12SiO20 nanocomposite filled with europium as a potentially attractive material to improving the solar cell efficiency.