Synthesis And Characterizations Of Luminescent Material Zn₂SiO₄: Mn

Zn2SiO4 has been identified as a very suitable host matrix for many rare earth and transition metal dopant ions for the efficient luminescence. A prominent green emission color has been reported on Zn2SiO4:Mn, it's one of the most promising alternatives to the traditional phosphors in electroluminescent devices for it's chemical and moisture stability property. Recently, Zn2SiO4:Mn phosphor was evaluated for use in medical imaging technology, and it was found to be appropriate for low-voltage radiography and fluoroscopy。The sinter property was studied first. Prepared by Sol-Gel method, the xerogel fired at 1100℃ for 2h was well crystallized. A series of drying method as regular method, supercritical drying method and heterogeneous distillation method was used. The phosphors prepared by heterogeneous distillation were composed of small irregular round-shaped grains which were about 60~160nm, shows bright green emission band at 525nm.In this paper, we also study the relationship between luminescent intensity and dopant concentration. With the ultraviolet excitation at 240nm, the phosphor can emit bright green luminescent at 525nm. The co-activated phosphor shows same excitation spectrum and emission spectrum with Mn-doped Zn2SiO4. The optimized dopant ratio(mol) is Zn2+: Mn2+: Er3+＝0.956:0.043:0.001. The nano-scale powder shows luminescent intensity approximate to the commercial powder.Furthermore, we used hydrothermal method to prepare Zn2SiO4:Mn. Under the pressure of 2.97MPa, the reaction was carried out in a autoclave at temperature of 250℃. This method can form crystallized Zn2SiO4 without high temperature sintering. The powder has not good emission intensity but good acicular morphology.