Zn_2SiO_4∶Mn^(2+)荧光粉的燃烧法合成及其发光特性

Preparation and Photoluminescence of Zn_2SiO_4∶Mn^(2+) Phosphor by Combustion Technique

用燃烧法成功合成了Zn2 -xSiO4∶xMn(0≤x≤ 0 .10 )粉末样品并表征了其发光特性。XRD测量结果表明 ,在 6 0 0℃下燃烧数分钟、90 0℃以上进行热处理 4h后 ,所得样品为单相Zn2 -xSiO4∶xMn(0≤x≤ 0 .10 ,Willemite)。监控 5 2 5nm发射 ,测得Zn2 -xSiO4∶xMn(0 <x≤ 0 .10 )的最强激发峰为Mn2 + 的6A1→4T1跃迁 (约 2 5 4nm)。 2 5 4nm激发下 ,Zn2 -xSiO4∶xMn(0 <x≤ 0 .10 )的最强发射峰为Mn2 + 的 3d电子组态内自旋禁戒的4T1→6A1跃迁 (约 5 2 5nm)。结果表明 ,发光强度、最强峰位、最佳激活剂浓度等与初始原料、燃烧温度、燃烧剂的用量。

Zn_2SiO_4∶Mn is well-known as green emitting phosphor in PDPs. Zn_2SiO_4∶Mn is also widely used in cathode ray tube(CRT), tri-color lamps, color television and thin film electroluminescence devices. Powder samples of Zn_2SiO_4∶Mn is usually prepared by solid state reaction. Recently, Zn_2SiO_4∶Mn phosphors are also synthesized by sol-gel, hydrothermal, spry pyrolysis method, etc.. In recent years, more and more attention is paid to combustion synthesis (also called self-propagation high-temperature synthesis) because of its advantages, such as production highly crystalline powders in the as-synthesized state, having higher surface areas, and more homogeneous etc. Zn_2SiO_4∶Mn(0≤x≤0.10) powder samples were synthesized successfully by solution combustion process, and its photoluminescence was also investigated. The single-phase of Zn_(2-x)SiO_4∶xMn(0≤x≤0.10,Willemite) was obtained by combustion synthesis at as low as 600 ℃ for few minutes, then by heat treatment at above 900 ℃ for 4 h. In the excitation spectra of Zn_(2-x)SiO_4∶xMn (0<x≤0.10), the strong broad excitation band at about 254 nm is due to ~6A_1→()~4T_1 transition of Mn^(2+) with monitoring at 525 nm emission. At about 525 nm, the intense broad band emission was observed under 254 nm excitation in Zn_(2-x)SiO_4∶xMn (0<x≤0.10). This broad band is attributed to ~4T_1→~6A_1 transition of Mn^(2+). SEM photography shows its spherical morphology. The results indicated that luminescence efficiency, the location of the strongest band and the optimum concentration of activator depend on starting materials, combustion temperatures, the dosage of fuels and the size of powder samples etc.