| Texto completo | |
| Autor(es): |
Diogenis, Isabela M. S.
[1]
;
Rodrigues, Emille M.
[1]
;
Mazali, Italo O.
[1]
;
Sigoli, Fernando A.
[1]
Número total de Autores: 4
|
| Afiliação do(s) autor(es): | [1] Univ Estadual Campinas, Inst Chem, Lab Funct Mat, Campinas, SP - Brazil
Número total de Afiliações: 1
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Journal of Luminescence; v. 232, APR 2021. |
| Citações Web of Science: | 2 |
| Resumo | |
The hierarchical core@shell nanostructure in upconversion nanoparticle (UCNP) has allowed high intensities of upconversion emission by interfacial energy transfer (IET) mechanism, which can also account for high down-shifting emission intensities observed for core@shell nanostructures. It is well accepted that the emission of active ions, sensitized by IET is originated from ions located into narrow core@shell interface, which has been shown by physically separation of donor and acceptor ions in the core@shell nanostructure. Herein we have spectroscopic proof of the preferential sensitization of the ions into the core@shell interface by IET. We have analyzed the excitation and emission spectra profiles of the Eu-III sensitized by Gd-III ions on hierarchically structured beta-NaYF4 nanoparticles. In this work, Eu-III emission occurs through a downshifting mechanism that is like the last step of the energy transfer pathway from Gd-III to active ions in nanostructured UCNPs as part of a known UC-IET processes. Photophysical results indicate that IET sensitizes mainly the Eu-III ions located at the core@shell interface, where these ions experience a variety of distorted chemical environments. Such a non-symmetrical electrical fields results in an inomogeneous broadening of D-5(0) -> F-7(2) transition emission band. The preferential, but not unique, sensitization of Eu-III ions by energy transfer from Gd-III ions located at distorted interface may shine light on the upconversion emission bands intensities observed in several works describing the IET in UCNPs and spectrocopically confirms that Gd-III-mediated emission occurs spatially in a narrow core@shell interfacial region. (AU) | |
| Processo FAPESP: | 14/50906-9 - INCT 2014: em Materiais Complexos Funcionais (INOMAT) |
| Beneficiário: | Fernando Galembeck |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |
| Processo FAPESP: | 13/22127-2 - Desenvolvimento de novos materiais estratégicos para dispositivos analíticos integrados |
| Beneficiário: | Lauro Tatsuo Kubota |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |