[摘要]：Synthesis of Pr3+ doped CaS phosphor has been reported through chemical co-precipitation route and post annealing in the presence of NaCl, KCl and NH4Cl flux. Good crystallinity and cubic CaS phase is achieved after post-precipitation calcinations of powder at 900 degrees C for 1 h duration. Pseudo-spherical morphostructural features of micron-size particles are observed for phosphor prepared via chemical route. Phosphor samples are also prepared via solid-state carbothermal reduction technique for comparative studies and exhibit dendrite like structures. Prominent excitation bands at 276, 320 nm are observed for the present phosphor samples. The emission spectra show a duo-band feature at 495 and 580 nm where a spectral overlap of host lattice emission due to intrinsic defects and characteristic spectral features of Prion due to (3)p(0)-H-1(4), P-3(1)-H-1(5), D-1(2)-H-3(4) and P-3(0)-F-3(2) transitions can be observed. The carbothermal route synthesized CaS:Pr shows spectral features of Pr ion due to (3)p(0)-H-1(4) and P-3(0)-F-3(j) transitions. Electron spin resonance investigations reveal the presence of unintentional Mn2+ through a sextet signature. F+ electron trapping center is detected having g = 2.0034. Thermoluminescence glow curves possess a broad duo-band feature between room temperature -100 degrees C and > 25 degrees C under host UV irradiation. Kinetic characterization using glow curve deconvolution reveals quasicontinuous distribution of traps having energy between 0.56 and 1.15 eV and frequency factors between 10(7) and 10(11)/sec. (C) 2009 Elsevier B.V. All rights reserved.
