Non-radiative relaxation of Yb3+ in highly porous γ-Al2O3

Autor:	Uwe Happek, S.P. Feofilov, A. A. Kaplyanskii, R.I. Zakharchenya, J.K. Krebs
Rok vydání:	1999
Předmět:	Materials science Photoluminescence Biophysics Nanoparticle Mineralogy General Chemistry Crystal structure Condensed Matter Physics Biochemistry Atomic and Molecular Physics and Optics Nanocrystalline material Ion Chemical physics Molecule Relaxation (physics) Porous medium
Zdroj:	Journal of Luminescence. :209-213
ISSN:	0022-2313
DOI:	10.1016/s0022-2313(99)00100-3
Popis:	Sol–gel grown aluminum oxide is a highly porous material composed of a network of nano-crystalline γ-Al2O3 particles. The sol–gel process allows the incorporation of trivalent rare-earth ions into the crystal structure. These ions can be used to study, via optical techniques, the structure and dynamics of the nanoparticles in this material. Here we report on optical studies of Yb3+-doped γ-Al2O3. We find non-exponential decay curves for the 2 F 5/2 to 2 F 7/2 Yb3+ fluorescence and a strong temperature dependence of the decay rate between 4 and 300 K. We show that this behavior is not caused by confinement but is indicative of non-radiative relaxation channels. The non-radiative relaxation channel is provided by OH molecules at the surface of the γ-Al2O3 nanoparticles, demonstrating the importance of surface effects in nanocrystalline materials.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::caa997c1fabb0f04be0736b3b8e57e0f https://doi.org/10.1016/s0022-2313(99)00100-3 Zobrazit plný text záznamu Full Text from ScienceDirect