Structure and photoluminescence properties of a rare-earth free red-emitting Mn~(2+)-activated KMgBO_3

摘要

In this combined X-ray diffraction and photoluminescence study, the coordination environment of Mn~(2+) and the photoluminescence of single Mn~(2+) doped KMgBO_3 phosphors were studied. Mn~(2+) occupies Mg2+ sites, which were coordinated by six O~(2?). The strong absorption of KMgBO_3:Mn~(2+) was ascribed to the strong relaxation of spin and parity forbidden d–d transitions of Mn~(2+). The emission bands were centered at 636 nm, regardless of the excitation wavelength and Mn~(2+) doping concentration. Mn~(2+) activated KMgBO_3 could be efficiently excited with the excitation of Mn~(2+) d–d transitions in the wavelength range of 300–475 nm. The red-shift of Mn~(2+) emission was because of the strong crystal field environment of Mn~(2+) afforded by KMgBO_3. The potential applications of the phosphors have been pointed out based on their absorption spectra, excitation and emission spectra, thermal quenching properties, and decay properties.