Luminescence Properties Of Cu Doped Natural Sodalite And Preparation

The thesis briefly describes the energy level structure of transition metal ions,and the basic concept of the crystal field theory and the crystal field splitting of dorbitals. An overview of the mineral materials particle characteries and opticalproperties、the mineral luminescence mechanism, as well as the recent advances onthe mineral luminescent materials. Introduce the main luminescent materialpreparation methods and characterization of the luminescent materials. On this basis,Cu doped natural Sodalite phosphors were synthesized by solid-state reaction methodat high-temperature. To examine chemical components of sodalite, we conductedelectron probe micro-analysis (EPMA) and energy dispersive spectroscopy (EDS)analysis using an electron probe scanning electron microscope spectrometer. Thestructure of Cu doped sodalite samples were characterized with X-ray diffraction(XRD). The VUV-VIS luminescence properties were measured at room temperature.By measuring the fluorescence lifetime、quantum yield efficiency、chromaticitycoordinates and chromaticity temperature, analysis the types of luminescence centers,Reveals the luminescence mechanism of the Cu-doped natural sodalite samples. Thechromaticity and the quenching process was discussed in our study.The results show that the excitation band at171nm attributed to host absorptionand the excitation bands around202nm,255nm,280nm and290nm correspondingwith3d94s�'3d10transition of Cu+ion. Cu existed in two lattice sites in the sodalitecrystal, including Cu1at the lattice site of Na+ions and Cu2between the compositelayers, and formed Cu1and Cu2luminescence center of Cu+ion respectively. Theseemission spectra with the blue-ray peak at420nm and470nm, which were obtainedby exciting the Cu1and Cu2luminescence center under different wavelength, and canbe attributed to the3d94s�'3d10electronic transition of Cu+ion. The mechanism ofluminescence and concentration quenching process were discussed. Fluorescencelifetime27.7s and36.6s、quantum yield efficiency0.73and0.50Respectivelycorresponding to the Cu1and Cu2luminescence center. Chromaticity coordinate(0.1598,0.0774) with280nm Excitation of sample is very close to standardchromaticity coordinates of blue phosphor at room temperature. Correlatedchromaticity Temperature30000K, purity87.4%. With the temperature increasingimprove the purity of sample. At the high temperature190℃, Chromaticitycoordinate (0.1541,0.0588), Correlated chromaticity Temperature30000K, purity92.2%. With increases the Cu doping concentration, appeared the concentrationquenching phenomenon of emission spectrum.Currently used in the manufacture of PDP phosphors excited by light with awavelength of a vacuum ultraviolet region. The main excitation wavelengths areincluded147nm,130nm and172nm. And high quantum efficiency of the sample, with good chromaticity, has reached the level of practical application. So the Cudoped natural Sodalite phosphor is likely as the PDP blue phosphor.