Highly luminescent doped nanoparticles embedded in porous silicon oxide
|Nima Taghavinia 1, Gilles Lerondel 2, Hisao Makino 3, Takafumi Yao 4|
1. Sharif University of Technology, Azadi Avenue, Tehran 14588, Iran
Yttrium silicate and zinc silicate nanoparticles were formed inside a transparent porous SiO2 template, by impregnating layers of porous silicon with nitrate solutions of yttrium and zinc, followed by appropriate heat treatment. Yttrium silicate nanoparticles were doped with red emitting Eu3+ and blue emitting Ce3+ ions, while zinc silicate nanoparticles were doped with blue emitting Eu2+ ions. Doping was carried out by adding appropriate impurity ions in the impregnation solution. The product is a dispersion of nanoparticles scattered inside a transparent porous SiO2. The photoluminescence of the samples show strong luminescence of the impurity ions upon UV illumination. The blue luminescence from the Ce3+ doped yttrium silicate nanoparticles is stronger than the commercial Y2SiO5:Ce3+ phosphors. The doped nanoparticles act effectively as "nanophosphors" stabilized inside the SiO2 porous matrix. The size of the nanoparticles was between 20nm to 200nm. The yttrium silicate nanoparticles show a mixture of Y2SiO5 and Y2Si2O7 phases, while the zinc silicate nanoparticles look more or less amorphous. Generally we observe an increasing trend in the luminescence intensity, as the extent of doping increases. In case of Eu3+, the luminescence decay time is shorter for higher doping. Detailed structural and optical analysis will be presented.
Presentation: oral at E-MRS Fall Meeting 2004, Symposium G, by Nima Taghavinia
See On-line Journal of E-MRS Fall Meeting 2004
Submitted: 2004-04-29 17:03 Revised: 2009-06-08 12:55