Utilize este identificador para referenciar este registo: http://hdl.handle.net/10773/20470
Título: KCa4(BO3)(3):Ln(3+) (Ln = Dy, Eu, Tb) phosphors for near UV excited white-light-emitting diodes
Autor: Reddy, Allu Amarnath
Das, Subrata
Goel, Ashutosh
Sen, Rupam
Siegel, Renee
Mafra, Luis
Prakash, G. Vijaya
Ferreira, Jose M. F.
Palavras-chave: CA-ALPHA-SIALON
LUMINESCENCE PROPERTIES
CRYSTAL-STRUCTURE
BAMGAL10O17-EU2+ PHOSPHOR
ENERGY-TRANSFER
PHOTOLUMINESCENCE
EXCITATION
CE3+
IONS
SR
Data: 2013
Editora: AMER INST PHYSICS
Resumo: A series of doped KCa4(BO3)(3):Ln(3+) (Ln: Dy, Eu and Tb) compositions were synthesized by solid-state reaction method and their photoluminescent properties were systematically investigated to ascertain their suitability for application in white light emitting diodes. The X-ray diffraction (XRD) and nuclear magnetic resonance (MAS-NMR) data indicates that Ln(3+)-ions are successfully occupied the non-centrosymmetric Ca2+ sites, in the orthorhombic crystalline phase of KCa4(BO3)(3) having space group Ama2, without affecting the boron chemical environment. The present phosphor systems could be efficiently excitable at the broad UV wavelength region, from 250 to 350 nm, compatible to the most commonly available UV light-emitting diode (LED) chips. Photoluminescence studies revealed optimal near white-light emission for KCa4(BO3)(3) with 5 wt.% Dy3+ doping, while warm white-light (CIE; X = 0.353, Y = 0.369) is obtained at 1wt.% Dy3+ ion concentration. The principle of energy transfer between Eu3+ and Tb3+ also demonstrates the potential white-light from KCa4(BO3)(3):Eu3+, Tb3+ phosphor. Whereas, single Tb3+ and Eu3+-doped systems showed bright green (Tb3+) and red (Eu3+) emissions, respectively. Having structural flexibility along with remarkable chemical/thermal stability and suitable quantum efficiency these phosphors can be promising candidates as white-light-emitter for near UV LEDs. Copyright 2013 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. [http://dx.doi.org/10.1063/1.4794189]
Peer review: yes
URI: http://hdl.handle.net/10773/20470
DOI: 10.1063/1.4794189
ISSN: 2158-3226
Versão do Editor: 10.1063/1.4794189
Aparece nas coleções: CICECO - Artigos



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