Visible PL phenomenon at room temperature in disordered structure of SrWO4 powder
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Data
2005-01-01
Autores
Anicete-Santos, M.
Lima, R. C.
Orhan, E.
Maurera, M. A. M. A.
Simoes, L. G. P.
Souza, G.
Pizani, P. S.
Leite, E. R.
Varela, José Arana [UNESP]
Longo, Elson [UNESP]
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Editor
Springer
Resumo
The SrWO4 (SWO) powders were synthesized by the polymeric precursor method and annealed at different temperatures. The SWO structure was obtained by X-ray diffraction and the corresponding photoluminescence (PL) spectra was measured. The PL results reveal that the structural order-disorder degree in the SWO lattice influences in the PL emission intensity. Only the structurally order-disordered samples present broad and intense PL band in the visible range. To understand the origin of this phenomenon, we performed quantum-mechanical calculations with crystalline and order-disordered SWO periodic models. Their electronic structures were analyzed in terms of band structure. The appearance of localized levels in the band gap of the order-disordered structure was evidenced and is a favorable condition for the intense PL to occur.
Descrição
Palavras-chave
electronic structure, order-disorder, oxide powder, photoluminescence, scheelite, SrWO4
Como citar
Journal of Computer-aided Materials Design. Dordrecht: Springer, v. 12, n. 2-3, p. 111-119, 2005.