ZnS/SiO_2介孔组装体系的发光性质

Optical property of ZnS/SiO_2 assembly

通过Sol-gel法得到SiO2介孔固体,浸泡热分解后获得ZnS/SiO2介孔组装体。吸收光谱和荧光光谱表明:随复合量增大,蓝移量减小;在氮气中退火后,吸收边位置和荧光谱中的峰位随退火温度升高向长波方向移动且发光增强,450℃以后减缓。经计算,颗粒尺寸的理论值与其自由激子半径相当,说明吸收边的移动起因于量子尺寸效应。

Monolithic mesoporous silica was prepared by a sol-gel technique. The ZnS/SiO2 assembly systems with different ZnS loading （0.05, 0.1, 0.2 and 0.5 mol/L） were obtained by immersing, followed by drying and thermal reaction. It was found that the optical absorption edges and the peaks of fluorescence spectrum have a red-shift with increasing the ZnS loading concentration. The photoluminescence intensity of samples is enhanced along with the increase of the annealing temperature and slows down for the samples annealed at temperature above 450℃. The calculated result shows that the size of ZnS particles in the mesoporous SiO2 is similar to its exciton radius in magnitude. The shift of the absorption edge is attributed to the quantum size effect.