Key Words:Light emitting diodes;Activation energy - Emission spectroscopy - Europium - Light - Light emission - Phosphors - Photoluminescence - Quenching - Rietveld refinement - Solid state reactions - Thermodynamic stability - X ray powder diffraction;Borate - Concentration quenching - Excitation and emission spectra - Photoluminescence properties - Solid state reaction method - Temperature dependent - White light emitting diodes - WLEDs
Abstract:The series of new green Ba<inf>(1&minus;x)</inf>Zn<inf>2</inf>(BO<inf>3</inf>)<inf>2</inf>:xEu²⁺(x = 0.02, 0.04, 0.06, 0.08, 0.10, 0.12) phosphors have been synthesized by solid state reaction method. The as-prepared phosphors were characterized by X-ray powder diffraction (XRD) and the structures were determined by Rietveld refinement. The photoluminescence properties were investigated, including excitation and emission spectra. The concentration quenching mechanism of Eu²⁺emission in BaZn<inf>2</inf>(BO<inf>3</inf>)<inf>2</inf>host was studied. The thermal stability of BaZn<inf>2</inf>(BO<inf>3</inf>)<inf>2</inf>:Eu²⁺phosphor was evaluated through evaluation of temperature-dependent luminescence. The activation energy (E<inf>a</inf>) for thermal quenching was calculated. Further, a green-emitting LED was fabricated by combination of an InGaN chip and the BaZn<inf>2</inf>(BO<inf>3</inf>)<inf>2</inf>: Eu²⁺phosphor to evaluate the application of BaZn<inf>2</inf>(BO<inf>3</inf>)<inf>2</inf>: Eu²⁺phosphor. All the results show that BaZn<inf>2</inf>(BO<inf>3</inf>)<inf>2</inf>:Eu²⁺phosphor is a potential green phosphor for near ultraviolet-based white light emitting diodes (WLED). &copy; 2017 Elsevier B.V.
Volume:190
Issue:
Translation or Not:no