| Texto completo | |
| Autor(es): |
de Queiroz, T. B.
[1, 2]
;
Botelho, M. B. S.
[1, 3]
;
Goncalves, T. S.
[1]
;
Dousti, M. Reza
[1]
;
de Camargo, A. S. S.
[1]
Número total de Autores: 5
|
| Afiliação do(s) autor(es): | [1] Univ Sao Paulo, Phys Inst Sao Carlos, BR-13566590 Sao Carlos, SP - Brazil
[2] Univ Bayreuth, Theoret Phys 4, D-95440 Bayreuth - Germany
[3] Univ Brasilia, BR-70910900 Brasilia, DF - Brazil
Número total de Afiliações: 3
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Journal of Alloys and Compounds; v. 647, p. 315-321, OCT 25 2015. |
| Citações Web of Science: | 13 |
| Resumo | |
A series of optically active Eu3+ and Tb3+ doped fluorophosphate glasses with compositions (BaF2)(0.25)(SrF2)(0.25)(AlF3)(0.10){[}Al(PO3)(3)](0.20)(YF3)(0.20-x)(Eu F3 and/or TbF3)(x) (x = 0 to 0.04) was prepared and characterized by optical spectroscopy. While embedded in the oxyfluoride host, the cited rare earth (RE) ions exhibit improved spectroscopic properties such as longer excited state lifetimes than in oxide glasses and intense emissions in the red (D-5(0) -> F-7(2), Eu3+), green and blue (D-5(4) -> F-7(5) and D-5(3),(5)G(6) -> F-7(5),F-7(4), Tb3+) spectral regions. Based on this fact, co-doped samples can be designed with appropriate concentrations of these two ions and generate tunable and white light upon excitation with suitable wavelengths, dispensing the need for a third blue emitting RE ion. Four co-doped samples with equal amounts of EuF3 and TbF3 and total concentration of 0.3, 0.5, 1.0 and 1.5 mol% were tested. Their CIE chromaticity coordinates were calculated for various excitation wavelengths in the region from 350 to 360 nm allowing tuned emission from blue to red. The long lifetime values of the emitting levels in these co-doped samples (iota approximate to 3.1 ms for Eu3+ D-5(0), and iota approximate to 4.0 ms for Tb3+ D-5(4)), associated with fairly high quantum yields (Q.Y. = 5-12%) of the samples indicate that these materials could be efficiently pumped by high power LEDs around 355 nm. (C) 2015 Elsevier B.V. All rights reserved. (AU) | |
| Processo FAPESP: | 13/07793-6 - CEPIV - Centro de Ensino, Pesquisa e Inovação em Vidros |
| Beneficiário: | Edgar Dutra Zanotto |
| Modalidade de apoio: | Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs |