Synthesis and Properties of Hetero-Dialkaline Hexafluorosilicate Red Phosphor KNaSiF₆:Mn⁴⁺

In this study, we demonstrate the synthesis of the hetero-dialkaline hexafluorosilicate red phosphor KNaSiF 6 :Mn 4+ by etching Si wafers in a HF/KMnO 4 /NaMnO 4 ·H 2 O mixed solution. The X-ray diffraction analysis indicates that the synthesized phosphor has an orthorhombic structure with the space group . The luminescence properties of the phosphor are studied by photoluminescence (PL) analysis, PL excitation spectroscopy, and luminescence lifetime measurements, and are found to be intermediate of those of homo-dialkaline K 2 SiF 6 :Mn 4+ and Na 2 SiF 6 :Mn 4+ red phosphors.