| Texto completo | |
| Autor(es): |
Teixeira, Mayara Mondego
;
Gobato, Yara Galva
;
Gracia, Lourdes
;
da Silva, Luis Fernando
;
Avansi Jr, Waldir
;
Assis, Marcelo
;
de Oliveira, Regiane Cristina
;
Prando, Gabriela Augusta
;
Andres, Juan
;
Longo, Elson
Número total de Autores: 10
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Journal of Luminescence; v. 220, p. 12-pg., 2020-04-01. |
| Resumo | |
To achieve a stable material capable of white-light emission, we fabricated Ca10V6O25 by both co-precipitation (CP) and microwave-assisted hydrothermal (MAH) methods at different temperatures. The effects of structural disorder at a short-range (Raman spectra), medium-range (UV-vis spectra), and long-range (X-ray diffraction) on the material structure and its effect on optical properties were investigated. Both CP and the MAH methods were efficient for obtaining pure Ca10V6O25 material with different morphologies. Significant changes in morphology and degree of structural order and disorder were found to affect the photoluminescence (PL) properties. All samples exhibited a broadband PL spectrum, characteristic associated to charge transfer processes of the [VO4](3-) group, as well as transitions that occurred in the energy levels located within the band gap. The samples obtained by the MAH method at temperatures of 100 degrees C and 120 degrees C exhibited a lower structural disorder (at long- and short-ranges), the CIE chromaticity coordinates were located in the white region, MAH100 (x = 0.311 and y = 0.348) and MAH120 (x = 0.350 and y = 0.368). Furthermore, we conducted a detailed study of temperature dependence of PL spectra. All samples displayed decreased luminescence intensity as temperatures increased and low values of activation energy (approximately 2 meV). Finally, the as-synthetized Ca10V6O25 material has interesting properties for possible applications as a white-emitting phosphor under ultraviolet excitation. (AU) | |
| Processo FAPESP: | 13/07296-2 - CDMF - Centro de Desenvolvimento de Materiais Funcionais |
| Beneficiário: | Elson Longo da Silva |
| Modalidade de apoio: | Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs |
| Processo FAPESP: | 18/01808-5 - Propriedades ópticas e de transporte em altos campos magnéticos de heteroestruturas e dispositivos semicondutores baseados em materiais bidimensionais (2d) |
| Beneficiário: | Yara Galvão Gobato |
| Modalidade de apoio: | Bolsas no Exterior - Pesquisa |