| Texto completo | |
| Autor(es): |
de Morais, Amanda Justino
;
Bispo-Jr, Airton Germano
;
Ferreira, Flavia de Sousa
;
Mazali, Italo Odone
;
Sigoli, Fernando Aparecido
Número total de Autores: 5
|
| Tipo de documento: | Artigo Científico |
| Fonte: | NEW JOURNAL OF CHEMISTRY; v. 47, n. 15, p. 8-pg., 2023-03-20. |
| Resumo | |
Hierarchically structured-lanthanide (Ln(III))-doped beta-NaGdF4 nanoparticles emitting by upconversion (UC), downconversion (DC) and/or downshifting (DS) are currently investigated for potential applications as anti-counterfeiting agents or in energy conversion. Yet, the role of doping concentration, excitation pump power density (P-exc), and Ln(III)-Ln(III) separation on the Ln(III)-to-Ln(III) energy transfer (ET), luminescence quenching, and emission color tunability need to be further elucidated to boost their luminescence. In light of that, herein, these issues are discussed in nanostructured beta-NaGdF4:Tb-III,Tm-III,Yb-III core@shell nanoparticles emitting by UC, DS, and DC. In the NaGdy-xTm0.015Yb0.20TbxF4@NaYF4 compositions, larger Tb-III amounts induce stronger Tb-III UC while for P-exc lower than 20 W cm(-2), both cooperative sensitization upconversion (CSU) and energy transfer upconversion (ETU) mechanisms may occur. On the other hand, for P-exc larger than 50 W cm(-2), energy migration upconversion (EMU) dominates the UC. By separating Tb-III from Tm-III and Yb-III in core@shell@NaGdF4 architectures, only the CSU and ETU mechanisms occur, while for P-exc densities larger than 40 W cm(-2), saturation of upconversion takes place. Upon 488 nm excitation, Tb-III DS and Yb-III DC emissions are noticed as well. Thus, this study helps to understand how the proper design of hierarchically structured nanoparticles can control the Ln(III)-to-Ln(III) ET mechanisms while their versatile excitation and multi-emission are interesting features for use as anti-counterfeiting agents or in energy conversion. (AU) | |
| Processo FAPESP: | 20/02614-0 - Silicatos emissores de luz branca dopados com lantanídeos e metais de transição para aplicação em diodos emissores de luz branca quente |
| Beneficiário: | Marian Rosaly Davolos |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |
| Processo FAPESP: | 21/08111-2 - Materiais conversores de luz à base de terras raras: marcadores luminescentes, sensores e amplificadores ópticos |
| Beneficiário: | Hermi Felinto de Brito |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |
| Processo FAPESP: | 21/06326-1 - Luminescência de íons lantanídeos: uma ferramenta óptica contra falsificações |
| Beneficiário: | Fernando Aparecido Sigoli |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |