| Texto completo | |
| Autor(es): |
Leite Silva, Camila M. B.
;
Bispo-Jr, Airton G.
;
Canisares, Felipe S. M.
;
Castilho, Shirley A.
;
Lima, Sergio A. M.
;
Pires, Ana M.
Número total de Autores: 6
|
| Tipo de documento: | Artigo Científico |
| Fonte: | LUMINESCENCE; v. 34, n. 8, p. 10-pg., 2019-07-25. |
| Resumo | |
Eu3+-beta-diketonate complexes are used, for example, in solid-state lighting (SSL) or light-converting molecular devices. However, their low emission quantum efficiency due to water molecules coordinated to Eu3+ and low photostability are still problems to be addressed. To overcome such challenges, we synthesized Eu3+ tetrakis complexes based on [Q][Eu(tfaa)(4)] and [Q][Eu(dbm)(4)] (Q1 = C26H56N+, Q2 = C19H42N+, and Q3 = C17H38N+), replacing the water molecules in the tris stoichiometry. The tetrakis beta-diketonates showed desirable thermal stability for SSL and, under excitation at 390 nm, they displayed the characteristic Eu3+ emission in the red spectral region. The quantum efficiencies of the dbm complexes achieved values as high as 51%, while the tfaa complexes exhibited lower quantum efficiencies (28-33%), but which were superior to those reported for the tris complexes. The structures were evaluated using the Sparkle/PM7 model and comparing the theoretical and the experimental Judd-Ofelt parameters. [Q1][Eu(dbm)(4)] was used to coat a near-UV light-emitting diode (LED), producing a red-emitting LED prototype that featured the characteristic emission spectrum of [Q1][Eu(dbm)(4)]. The emission intensity of this prototype decreased only 7% after 30 h, confirming its high photostability, which is a notable result considering Eu3+ complexes, making it a potential candidate for SSL. (AU) | |
| Processo FAPESP: | 15/10394-1 - Filmes LBL luminescentes de Ba2SiO4 dopado com terras raras obtido via sol-gel para aplicação em LEDs brancos |
| Beneficiário: | Airton Germano Bispo Júnior |
| Modalidade de apoio: | Bolsas no Brasil - Mestrado |
| Processo FAPESP: | 16/20421-9 - Dispositivos tricromáticos a base de Ba2SiO4:Eu3+ e/ou Tb3+: síntese sol-gel e deposição eletroforética visando aplicação em LEDs brancos |
| Beneficiário: | Airton Germano Bispo Júnior |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado Direto |
| Processo FAPESP: | 12/13876-9 - Efeitos ópticos e estruturais da variação da concentração do íon dopante Eu(III) na matriz Ba2SiO4 sintetizada via sol-gel |
| Beneficiário: | Airton Germano Bispo Júnior |
| Modalidade de apoio: | Bolsas no Brasil - Iniciação Científica |