| Abstract: Using La2(SO4)3 and the active carbon powder as reactants,
La2O2S∶Mn2+ red phosphor was synthesized by microwave radiation method. The phosphor was characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), laser-diffraction size analyzer and fluorospectrophotometer. The XRD analysis showed that the phosphor was pure phase
La2O2S. The phosphor of La2O2S∶Mn2+ showed hexagonal crystal structure with diverse shapes, such as spherical and rod, with average particle size of 10.22 μm. The emission and excitation spectra of the phosphor were determined by fluorospectrophotometer and the results showed that the excitation spectrum of the phosphor under 600 nm emission wavelength was excitation bands between 250 nm and 350 nm with a peak value of 303 nm. Then ,when exicited under UV 303 nm, the phosphor showed broad band emission of 550~700 nm with a peak at 607 nm. In addition, the optimal effects were obtained for the phosphor preparation when the concentration of the activator
Mn2+ was xMn=0.01, the ratio of C and O (nC / nO) in the reactants was 0.6∶1, and the time of reaction was about 1 h.
La2O2S∶Mn2+ has strong absorption of UV spectrum and can emit bright red light. |
