Photoluminescent properties of K2SnF6·H2O:Mn4+ red phosphor

A red phosphor K2SnF6·H2O:Mn4+ has been synthesized from metallic tin by wet chemical etching in HF/KMnO4 mixed solution. The X-ray diffraction pattern suggests that the red phosphor has the form of K2SnF6·H2O with the orthorhombic structure (space group = D2h24-Fddd). The luminescent properties of K2SnF6·H2O:Mn4+ are studied using photoluminescence (PL) and PL excitation spectroscopy. The room-temperature zero-phonon line emission and excitation energies in K2SnF6·H2O:Mn4+ are found to occur at ∼2.0 eV (2E → 4A2), ∼2.42 eV (4A2 → 4T2), and ∼2.87 eV (4A2 → 4T1). Some local vibronic modes and also zero-phonon line emission doubly split being due to the hydration-related orthorhombic distortion of the MnF62- octahedron in the K2SnF6·H2O host lattice.