Key Words:Phosphors;Europium - Fluorescence - High temperature applications - Light emission - Light emitting diodes - Phosphates - Photoluminescence - Rare earths - Solid state reactions - Strontium compounds - Thermodynamic stability;Blue light emitting diodes - Blue-emitting phosphor - Concentration quenching - Excitation spectrum - Fluorescence lifetimes - Fluorescence properties - High temperature solid-state reaction - Photoluminescence properties
Abstract:A series of blue-emitting phosphors Sr<inf>5</inf>(PO<inf>4</inf>)<inf>3</inf>F: Eu²⁺were synthesized by traditional high temperature solid-state reaction method. The micro-morphology and photoluminescence properties of the phosphors were investigated. The Sr<inf>5</inf>(PO<inf>4</inf>)<inf>3</inf>F: Eu²⁺phosphors exhibit broad excitation spectra ranging from 250 to 420&nbsp;nm, and an intense asymmetric blue emission band peaking at 435&nbsp;nm. Two different Eu²⁺emission centers in Sr<inf>5</inf>(PO<inf>4</inf>)<inf>3</inf>F: Eu²⁺phosphors were confirmed via their fluorescence properties. The concentration quenching mechanism, fluorescence lifetime and thermal stability of Sr<inf>5</inf>(PO<inf>4</inf>)<inf>3</inf>F: Eu²⁺phosphors were studied in detail. The thermal stability can be improved obviously by anion substitution. The CIE chromaticity coordinates of Sr<inf>5</inf>(PO<inf>4</inf>)<inf>3</inf>F: Eu²⁺phosphors with different Eu²⁺-doped concentrations were calculated. A blue light-emitting diode was fabricated by combination of a 370&nbsp;nm InGaN chip and the prepared phosphor Sr<inf>5</inf>(PO<inf>4</inf>)<inf>3</inf>F: Eu²⁺. The present work suggests that Sr<inf>5</inf>(PO<inf>4</inf>)<inf>3</inf>F: Eu²⁺is a potential phosphor applied in InGaN-based LEDs. &copy; 2017 Elsevier B.V.
Volume:221
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Translation or Not:no