ISSN:
1662-0356
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Natural Sciences in General
,
Technology
Notes:
We present the details of the sol-gel processing used to realize inverse silica opal, wherethe silica was activated with 0.3 mol% of Er3+ ions. The template (direct opal) was obtainedassembling polystyrene spheres of the dimensions of 260 nm by means of a vertical depositiontechnique. The Er3+-activated silica inverse opal was obtained infiltrating, into the void of thetemplate, the silica sol doped with Er3+ ions and subsequently removing the polystyrene spheres bymeans of calcinations. Scanning electron microscope showed that the inverse opals possess an fccstructure with a air hollow of about 210 nm. A photonic band gap in the visible range was observedfrom reflectance measurements. Spectroscopic properties of Er3+activated silica inverse opal wereinvestigated by photoluminescence spectroscopy. A bandwidth of 21 nm was measured for the 4I13/2→ 4I15/2 transition of Er3+ ions upon excitation at 514.5 nm. The luminescence decay curve of the4I13/2 metastable state of the Er3+ ions presents a lifetime τ = 16.8 ± 0.1 ms giving a very highquantum efficiency of the fabricated system. Core-shell Er3+-activated silica spheres, where the coreis the silica sphere and the shell is an Er2O3-SiO2 coating is proposed as a possible route for opalfabrication. For core-shell system a quantum efficiency of about 70% was estimated
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/42/transtech_doi~10.4028%252Fwww.scientific.net%252FAST.55.118.pdf
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