Materials Research Bulletin, Vol.83, 211-216, 2016
Self-activated photoluminescence and persistent luminescence in CaZr4(PO4)(6)
This study reports a rare luminescence of a self-activated zirconate sample. Phosphor CaZr4(PO4)(6) was prepared via typical solid-state reaction. The photoluminescence and persistent luminescence properties of CaZr4(PO4)(6) were investigated. X-ray diffraction and diffuse reflectance spectrum were utilized to characterize the phosphor. The photoluminescence excitation and emission spectra, the fluorescence decay curve and the thermoluminescence glow curve were investigated. Both the fluorescence and persistent luminescence can be excited by UV light (lambda < 300 nm) and result in cyan emisson band peaked at 460 nm with fluorescence lifetime of about 4.3 mu s. The origin of the luminescence was suggested from the charge transfer transition from central zirconium ion to oxygen ligand. Based on experimental results, the trapping and detrapping processes of charge carriers were studied. A rudimentary energy level scheme was proposed to explain the mechanisms of persistent luminescence as well as photoluminescence. (C) 2016 Elsevier Ltd. All rights reserved.