Influence of high-temperature treatment on the structure and emission properties of opal doped with erbium

• Published in: Physics of the solid state 2009-06, Vol.51 (6), p.1154-1159
• Main Authors: Masalov, V. M., Shteĭnman, É. A., Tereshchenko, A. N., Kudrenko, E. A., Bazhenov, A. V., Koval’chuk, M. A., Khodos, I. I., Emel’chenko, G. A.
• Format: Article
• Language: English
• Subjects: Optical Properties; Physics; Physics and Astronomy; Solid State Physics
• ISSN: 1063-7834; 1090-6460
• DOI: 10.1134/S1063783409060122

The influence of high-temperature treatment of opal—erbium composites on their spectral properties in the wavelength region of 1.5 μm is investigated, the dependence of the luminescence intensity on the erbium concentration is measured, and the structure of the composite after high-temperature treatment is examined using transmission electron microscopy. The regular structure of the composites undergoes considerable transformations up to the complete loss of periodicity upon annealing at a temperature of 1500 K for 10 h and more. The composites in this case are sintered into a homogeneous substance. Pores disappear, and erbium oxide inclusions in the form of 30- to 70-nm regular solid spheres are observed instead. Measurements of the luminescence spectra in the wavelength region of 1.5 μm for the opal-erbium composites with erbium oxide concentrations in the range 0.25–16.00 wt % have shown that the luminescence yield reaches the maximum at an Er 2 O 3 content of 1 wt % in the composite. Analysis of the influence of the temperature and time of heat treatment on the luminescence intensity of the samples has revealed a nonmonotonic character of the dependence on the annealing time for all the temperatures under investigation. The factors responsible for this behavior are discussed. The reflection spectra of the opal-Er 2 O 3 (1 wt %) composites after heat treatment have demonstrated that the photonic band gap of the samples degrades at annealing temperatures of 1300 K and higher. A method proposed for retaining the periodic structure upon heat treatment consists in introducing the stabilizing phase into the opal.