A novel Cs2NbOF5:Mn4+ oxyfluoride red phosphor for light-emitting diode devices.
Dalton Trans
; 47(45): 16048-16056, 2018 Nov 22.
Article
em En
| MEDLINE
| ID: mdl-30206588
ABSTRACT
The addition of a red-emitting phosphor to YAGCe3+-based white light-emitting diodes (WLEDs) greatly facilitates their applications in the field of high-color-rendering-index warm solid-state lighting. It is highly desirable to develop a red phosphor with satisfactory spectral features and low synthesis cost. In this study, a novel non-rare-earth and nonequivalent doping type of Cs2NbOF5Mn4+ oxyfluoride red-emitting phosphor with high luminous efficiency was obtained via a facile room-temperature co-precipitation method, and its morphology and luminescent properties were investigated in detail. The Cs2NbOF5Mn4+ phosphor with micro-rod-like morphology exhibited broad band absorption at blue light region (â¼474 nm) and narrow bandwidth emissions at red region (â¼633 nm). The color purity of the Cs2NbOF5Mn4+ phosphor was calculated to be about 99%, and the internal quantum yield (QY) under 474 nm excitation was 63.4%. The concentration quenching of Mn4+ in Cs2NbOF5 matrix was mainly due to dipole-dipole interactions, and the activation energy of temperature quenching was calculated to be â¼0.2610 eV. The demonstration of a blue InGaN LED chip in combination with a blend of newly developed Cs2NbOF5Mn4+ red phosphor and YAGCe3+ yellow phosphor greatly decreased the correlated color temperature (CCT) from 6255 to 3517 K while significantly improving the color rendering index (CRI) from 72.5 to 87.5. It deserves to be mentioned that the brand-new matrix to phosphor in the present study can be extended to various niobium/tantalum oxyfluoride series, which is very helpful for developing and designing new red phosphors.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
Dalton Trans
Assunto da revista:
QUIMICA
Ano de publicação:
2018
Tipo de documento:
Article