Investigations on structural and spectral properties of undoped and Mn~(2+) doped SrZn_2(PO_4)_2 nanophosphors for light emitting devices

摘要

SrZn2(PO4)(2) (SZP) and Mn2+ doped SrZn2(PO4)(2) (SZP: Mn) nanophosphors are prepared through solution combustion synthesis at a moderate temperature of 823K. The nanophosphors are characterized by structural and spectral investigations systematically. X-ray diffraction (XRD) analysis confirms the monoclinic phase of SrZn2(PO4)(2) with average crystallite size around 60-65nm. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images of the samples have shown irregular morphology. The fundamental vibrational modes of different phosphate groups are confirmed by Fourier transform infrared (FT-IR) spectroscopic analysis. Optical absorption spectrum exhibits Mn2+ characteristic bands are in visible region. Electron paramagnetic resonance (EPR) study describes octahedral environment of Mn2+ ions around the ligands in the host. Photoluminescence (PL) spectra show peaks in blue and yellow-orange region. Commission Internationale de l'Eclairage (CIE) and color correlation temperature (CCT) values indicate that SZP and SZP:Mn nanophosphors are potentially good for solid state lightening and white light emitting diodes (WLEDs).