Non-stoichiometric Ce-doped LiAl5O8 phosphors: Synthesis, structural and optical properties

Abstract Structural and optical properties of non-stoichiometric pure and doped LiAl5O8 prepared via a simple sol-gel using glucose were investigated. X-ray diffraction, scanning electron microscopy, and photoluminescence measurements were used to characterize the prepared samples. By employing Ce3+ as trivalent ion doped in the LiAl5O8 lattice, the effects of non-stoichiometry of Li+ on the network parameters and luminescence properties were systematically investigated. A non-stoichiometric in LiAl5O8 led to a lattice change and local symmetry distortion. Lattice variation and doping effects, and its relevant defect chemistry had a significant impact on the luminescence properties. The luminescence emission of Ce-doped LiAl5O8 phosphors showed an intensity change with variation of Lithium concentration, which is thought to be related to doping effects and variation of lattice parameters. Therefore, with nonstoichiometric control, the luminescence of Ce-doped LiAl5O8 phosphors can be well regulated and optimized. Emission lines assigned to Fe3+ and Cr3+ impurities originated from start reagents used in the sample synthesis were also observed.