Characterization and properties of red-emitting Sr2YNbO6:Mn4+ phosphor for white-light-emitting diodes

A series of pure Mn4+-doped red Sr2YNbO6 (SYN) phosphors were synthesized through the solid-state reaction method. The crystal structure, composition, luminescence properties, and thermal stability of the phosphors were determined through X-ray powder diffraction analysis, scanning electron microscopy, energy-dispersive X-ray spectrometry, and photoluminescence excitation (PLE) spectrometry. The photoluminescence decay curve and temperature-dependent photoluminscence spectra of the phosphors were also obtained. A broad absorption band at 200-550 nm is present in the UV-Vis spectra of the phosphors. Moreover, the PLE spectra of the phosphors present two broad excitation bands at 255-420 and 460-540 nm. These results illustrate that the SYN:Mn4+ phosphors are suitable for application in UV chips. The phosphor emits red light (675 nm) under excitation with 310 nm light. Crystal field analysis indicates that only the Mn4+ luminescent center is present in the phosphors. The calculated activation energy of the phosphors is 0.381 eV. This result proves that the phosphors possess good thermal stability. The chromaticity coordinates of the phosphors (0.699, 0.302) are close to the standard values set by the National TV Standards Committee (0.666, 0.333). All analytical results show that SYN:Mn4+ phosphors have considerable potential applications in white-light-emitting diodes.