Jump to main content
Jump to site search


Luminescence color tuning and energy transfer properties in (Sr,Ba)2LaGaO5:Bi3+,Eu3+ solid solution phosphors: realization of single-phased white emission for WLEDs

Abstract

Recently, controllable luminescence tuning and single-phased white light emitting have been extensively studied to improve the luminescence performances of phosphors for white light-emitting diodes (WLEDs). In this work, the controllable photoluminescence tuning from bluish-green to red region was successfully achieved in Bi3+, Eu3+-codoped Sr2-yBayLaGaO5 solid solutions, combining the effects of crystallographic site engineering and energy transfer. The phase composition and structural variation of the designed phosphors were thoroughly analyzed through X-ray powder diffraction (XRD) and Rietveld refinement. The effects of cation substitutions on the photoluminescence properties were investigated in detail and corresponding mechanism was proposed. The regular red-shift of Sr2-yBayLaGaO5:0.02Bi3+ in bluish-green region could be observed when Sr2+ was substituted by Ba2+, which is attributed to crystal field splitting and nephelauxetic effect. The red-shift emission of Ba2LaGaO5:0.02Bi3+ phosphor with gradually increasing excitation wavelength reveals that Bi3+ ions occupy different cation sites to form multiple luminescent centers. Besides, the efficient energy transfer was designed and successfully realized in Sr2-yBayLaGaO5:0.02Bi3+, zEu3+ (y = 0-2.0; z = 0-0.20) samples. The energy transfer efficiency can reach up to 88%, 91% and 77% at z = 0.20 for y = 0, 1.0 and 2.0, respectively. Moreover, the thermal quenching behaviors of the studied phosphors reveals that the codoping of Eu3+ could efficiently improve the thermal stability of Sr2LaGaO5:0.02Bi3+ phosphor. Finally, the WLED devices were fabricated by composing of 370 nm UV chips and single-phased Sr2-yBayLaGaO5:0.02Bi3+, 0.05Eu3+ (y = 0, 1.0, 2.0) phosphors. The as-fabricated devices presented relatively excellent EL performances, the color coordinates of which all locate in the warm white light region. These results indicate the as-prepared Sr2-yBayLaGaO5:Bi3+, Eu3+ phosphors can be potential candidates for color tuning and efficient single-phased white emission in UV-based WLED lighting applications.

Back to tab navigation

Supplementary files

Publication details

The article was received on 07 Sep 2019, accepted on 07 Oct 2019 and first published on 09 Oct 2019


Article type: Paper
DOI: 10.1039/C9TC04938J
J. Mater. Chem. C, 2019, Accepted Manuscript

  •   Request permissions

    Luminescence color tuning and energy transfer properties in (Sr,Ba)2LaGaO5:Bi3+,Eu3+ solid solution phosphors: realization of single-phased white emission for WLEDs

    D. Liu, P. Dang, X. Yun, G. Li, H. Lian and J. Lin, J. Mater. Chem. C, 2019, Accepted Manuscript , DOI: 10.1039/C9TC04938J

Search articles by author

Spotlight

Advertisements