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Eu(II)-Activated Silicates for UV Light-Emitting Diodes Tuning into Warm White Light

Texto completo
Autor(es):
Bispo-Jr, Airton G. ; Lima, Sergio A. M. ; Carlos, Luis D. ; Pires, Ana M. ; Ferreira, Rute A. S.
Número total de Autores: 5
Tipo de documento: Artigo Científico
Fonte: ADVANCED ENGINEERING MATERIALS; v. 22, n. 8, p. 10-pg., 2020-05-26.
Resumo

White-light-emitting diodes (WLEDs) are the main white light source for general lighting due to high-luminous efficacy (>150 lm W-1), long lifespan (5 x 10(4) h), and environmentally friendly properties. Despite the current maturity and reliability of the solid state-lighting field, the control of the correlated color temperature (CCT) tuning is still a challenge, arising from the lack of red emission color in the current design of commercial WLEDs. Moreover, as this aspect is often associated with dysregulations of the human circadian rhythm, the need for novel WLEDs is of enlarged societal relevance. In this scope, herein, warm WLED prototypes are fabricated by coating near-UV-emitting LEDs with a mixture of the yellow-emitting polyphasic Sr2SiO4:Eu(II) (S2S) and the blue-emitting BaMgAl10O17:Eu(II) (BAM) phosphors dispersed in poly(methyl methacrylate). As the amount of S2S increases in the phosphor mixture, the CCT values of the WLEDs decrease from 6500 K (ideal for daylight application) to 4000 K (ideal for night light application), with a luminous efficacy of radiation of 404 lm W-1, among the best figures of merit for WLEDs. Furthermore, all the WLED devices also display a desirable color rendering index (CRI > 75), comparable with the commercial WLED, independent on the operating voltage. (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: 17/21995-1 - 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 Exterior - Estágio de Pesquisa - Doutorado Direto