Photoluminescence and Raman scattering spectroscopies of BaSiF6:Mn4+ red phosphor

Abstract

We report on a simple method of synthesizing BaSiF6:Mn4+ red phosphor by chemical reaction of BaCl2·2H2O in a H2SiF6 solution. The Mn4+-activated BaSiF6 phosphor exhibits sharp red emission peaks at ∼630 nm. The optical properties of BaSiF6:Mn4+ are investigated using photoluminescence (PL) analysis, PL excitation spectroscopy, luminescence decay time measurement, and Raman scattering spectroscopy. The zero-phonon line (ZPL) emission and excitation peaks in BaSiF6:Mn4+ are observed to occur at ∼1.99 eV (2E → 4A2), ∼2.43 eV (4A2 → 4T2), and ∼2.86 eV (4A2 → 4T1) at 300 K. The ZPL and phonon-assisted emission peaks show clear splittings with energy of ∼3 meV being due to the trigonal distortion of the MnF62− octahedron in the BaSiF6 host. A single exponential decay time of ∼6.5 ms is observed, which is indicative of the forbidden character of the intra-d-shell transitions in Mn4+ ions. Temperature dependence of the PL intensity is also measured between T = 20 and 300 K with steps of 10 K and interpreted by taking into consideration the Bose−Einstein phonon statistics together with the thermal quenching process.