Luminescence properties of cerium doped nanocrystalline yttrium silicate

Abstract

Here we report the preparation of nanocrystalline silica capped yttrium silicate doped with cerium and a study on its photoluminescence (PL) properties. The preparation method presented is simple and unique and can easily be scaled up for bulk production. The material shows blue luminescence at room temperature, and it is enhanced by a few orders of magnitude upon annealing. The PL intensities of these nanocrystalline samples are much stronger than similar bulk samples. The annealing temperatures required are much less than the bulk sample formation temperatures. Such annealing related PL enhancement is attributed to the formation of the optimum nanocrystalline size required for strong luminescence from nanoparticles due to the doped rare earth ions and quantum confinement related effects. It was also suggested that nano-Y 2 SiO 5 has a relatively more intense blue emission than the nano-Y 2 Si 2 O 7 phase. This is attributed to the position of the 5d level of Ce 3+ in the energy band.

Degradation of Y2SiO5:Ce phosphor powders

“…This spectrum is characteristic of the doublet character of blue light emission from Ce 3+ , due to the 4f ground state splitting [7,13,19]. Ce 3+ has an electron configuration of [Xe].4f 1 .5d 1 .6s 2 with the 5d and 6s electrons that shield the inner 4f electron.…”

“…It is postulated [7,19] that in Y 2 SiO 5 :Ce the transition is more likely to be from the 5d levels to the 4f 5/2 level giving rise to a broad band emission peak between 400 and 600 nm. Transition from the first 5d levels results in emission between 400 and 475 nm.…”

Growth and luminescence characteristics of cerium-doped yttrium pyrosilicate single crystal

“…Trails of Fz growth of Gd 2 Si 2 O 7 :Ce crystal have been carried out and this scintillator shows much better scintillation performance than GSO:Ce crystal [11,12]. Powder samples of YPS:Ce [13][14][15] and europium doped YPS [16] were obtained and their photoluminescence properties were also reported. In order to give a further study on the luminescent properties of YPS:Ce, it is necessary to get YPS:Ce single crystal.…”

Influence of vinyltriethoxysilane concentration on structural and luminescent characteristics of cerium doped yttrium based silicate phosphors

“…Since X2-Y 2 SiO 5 and α-Y 2 Si 2 O 7 crystalline phases were put in evidence, the photoluminescence (PL) and excitation (PLE) spectra are used to highlight the incorporation of cerium in different sites as the structure of silicate is changing. It is postulated that in Y 2 SiO 5 :Ce transitions from the 2 F 5/2 level are preferred (related to band at $ 400 nm), while in Y 2 Si 2 O 7 :Ce transitions from the 2 F 7/2 level are more likely [47]. Fig.…”