Study on luminescence and thermal stability of blue-emitting Sr_5(PO_4)_3F: Eu~(2+) phosphor for application in InGaN-based LEDs

摘要

A series of blue-emitting phosphors Sr_5(PO_4)_3F: Eu~(2+) were synthesized by traditional high temperature solid-state reaction method. The micro-morphology and photoluminescence properties of the phosphors were investigated. The Sr_5(PO_4)_3F: Eu~(2+) phosphors exhibit broad excitation spectra ranging from 250 to 420 nm, and an intense asymmetric blue emission band peaking at 435 nm. Two different Eu~(2+) emission centers in Sr_5(PO_4)_3F: Eu~(2+) phosphors were confirmed via their fluorescence properties. The concentration quenching mechanism, fluorescence lifetime and thermal stability of Sr_5(PO_4)_3F: Eu~(2+) phosphors were studied in detail. The thermal stability can be improved obviously by anion substitution. The CIE chromaticity coordinates of Sr_5(PO_4)_3F: Eu~(2+) phosphors with different Eu~(2+) -doped concentrations were calculated. A blue light-emitting diode was fabricated by combination of a 370 nm InGaN chip and the prepared phosphor Sr_5(PO_4)_3F: Eu~(2+) . The present work suggests that Sr_5(PO_4)_3F: Eu~(2+) is a potential phosphor applied in InGaN-based LEDs.