Structural and optical properties of Co2+-doped SrMg2(PO4)2 nanopowder: a new novel NUV LED material

Solid-state reaction method was employed to synthesize Co2+-doped SrMg2(PO4)2 nanopowder and characterized by different techniques to study the structural, morphological, optical, and photoluminescence effects. X-ray diffraction (XRD) analysis revealed that prepared nanopowder structure is monoclinic, and lattice parameters were evaluated. The average crystallite size, micro strain, and dislocation density were calculated and compared with Williamson-Hall method. The morphology of prepared sample was analyzed by SEM images and grain size obtained in nano range. EDS spectrum confirms the presence of desired elements of as prepared sample. The optical and EPR data exhibits distorted octahedral site symmetry of dopant with host material. Photoluminescence (PL) emission spectrum of prepared nanopowder exhibits a single broad band in visible region which represents bright blue color. CIE chromaticity coordinates, and CCT were found from emission spectrum. FTIR spectrum shows vibrational bands related to phosphates, P-O-H, and hydroxyl ions.