Preparation of Long Lasting Phosphor by New Method
- PDF / 260,499 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 62 Downloads / 249 Views
1074-I10-12
Preparation of Long Lasting Phosphor by New Method Hu Jin, Zhu Xiaoqin, Chen Donghua, Wan Kaijun, and Guo Yuzhong Kunming University of Science and Technology, Kunming, 650093, China, People's Republic of ABSTRACT The composite particle of Al(OH)3 and Sr(OH)2, was obtained by means of the hydrolytic reaction of the activated Al-Sr alloy particle in water. As a precursor, it could be used to prepare long after phosphor Eu, Dy co-doped SrAl2O4 by the modified solid state reaction at 1300°C. The components and microstructure of the composite particle were investigated by XRD, SEM and EDS techniques, and the luminescent characteristics and the afterglow properties of the long afterglow material were also measured at the same time. The experimental results showed that, the distribution of the two elements Al and Sr was uniform in the microstructure of the composite particle, and the contacting surfaces between the solid reactants were increased effectively at high temperature, and the diffusive paths were abbreviated. Therefore, the reaction velocity was increased, the sinter temperature descended and the luminescent properties enhanced. INTRODUCTION SrAl2O4 is a good host material because of its wide band gap[1]. By means of doping rare earth ions, it becomes a kind of long afterglow photoluminescence material, which can store light energy and glow slowly at dark environment[2-3]. Compared with ZnS phosphor, Eu, Dy codoped SrAl2O4 has excellent properties such as no harmful radioactivity, high initial intensity, long duration time and chemical stability, which has attracted more and more interests during the recent years, and is widely used in many fields. The afterglow lifetime and intensity can be enhanced by co-doping rare earth Eu2+ and Dy3+. Eu, Dy co-doped SrAl2O4 is conventionally prepared by the solid state reaction method[4], which needs extremely high temperature and a lengthy period of sintering time. As a result, the size of the particles is relatively large and it is difficult to crush the hard phosphor blocks into small particles, which decreases the luminescence intensity. During the recent years, several preparation methods have been developed for the synthesis of the pure single phase Eu, Dy co-doped SrAl2O4. The major goal is the increase of the initial brightness and duration time, as well as the decrease of the sintering temperature. T.R.N.Kutty and R.Jannathan synthesized Eu, Dy co-doped SrAl2O4 by means of a hydrothermal reaction[5]. A floating zone technique for preparation of Eu, Dy co-doped SrAl2O4 had been applied by T.Katsumata et al[6]. V.Abbruscato produced the strontium aluminate by a floating zone technique[7]. J.Kingsley et al used a combustion method to synthesize Eu, Dy co-doped SrAl2O4[4].
However, the most economic and widely used method is still the solid state reaction. With the view to develop a modified solid state reaction method, the hydrolysate of Al-Sr alloy particle was used as a precursor in this investigation to synthesize Eu, Dy co-doped SrAl2O4 at lower sin
Data Loading...
