The VUV Luminescence Properties Of MMgSi₂O₆: Re (M=Ca, Sr, Ba; Re=Eu, Tb, Ce)

In recent years, the interest has been in the development of new and efficient plasma phosphors to realize a gas discharge color picture display panel and mercury-free fluorescent lamps. Silicate phosphors are promising as candidates of host materials for the new VUV phosphors with various crystal structures and high chemical stability. Herein, we report the crystal structure and VUV luminescence property of MMgSi2O6: Re (M=Ca, Sr, Ba, Re=Eu, Tb, Ce) as the new VUV phosphor.In this work,a series of powder samples of MMgSi2O6: Re (M=Ca, Sr, Ba, Re=Eu,Tb, Ce) were prepared by the conventional solid state reaction. The data are in good agreement with those given in No. (Ca:83-1820, Ba:86-0419, Sr:75-1736) of JCPDS data files. The properties of structure, VUV excitation properties and Luminescence properties under VUV excitation were studied. MMgSi2O6: Re (M=Ca, Sr, Ba,Re=Eu, Tb, Ce) belongs to the monoclinic space group, and the crystal structure does not change as Eu or Tb ions are doped to the crystal lattice.In MMgSi2O6:Eu3+(M=Ca, Sr, Ba), the excitation spectrum show strong absorption in the VUV region with the broad absorption band at 130-170nm due to the host , and another absorption band edge at 230nm is due to the(CTS) of Eu3+ .The emission spectrum of MMgSi2O6:Eu3+(M=Ca, Sr, Ba)have revealed an intense and sharp (611 nm) red color emission from Eu 3+ (5D0→7F2) transition under 147nm VUV excitation. A small excess of SiO2 is used in synthesizing inorganic phosphor materials in order to obtain complete solid state reaction among the reacting species and to avoid the presence of strongly absorbing cationic species in the final phosphor product. However, if the amount of excess SiO2 increases, PL intensity may considerably decrease due to the increased presence of unreacted SiO2 in the end phosphor product. It can be seen tnat the intensity of the emission peaking increases with the increasing of H3BO3.In MMgSi2O6:Eu2+(M=Ca, Sr, Ba), While Ca2+ is replaced with Sr2+ or Ba2+ , the Eu2+ emission shifts to shorter wavelength.The excitation and emission spectra of these phosphors showed that all are broadband due to 4f–4f 5d transitions of Eu.When the divalent Eu ions substitute for the large divalent alkaline earth ions, the shifting and broadening in the emission spectra of Eu2+ is most pronounced in Ba2+ sites, less pronounced in Sr2+ sites and least pronounced in Ca2+ sites. Different host structures and crystallographic distortions will influence the crystal field environment of rare earth...