硫化镉纳米粒子的制备及其荧光性质研究

Syntheses of Cadmium Sulfide Nanoparticles and its Photoluminescence Property

采用溶胶凝胶法,以硫脲作为修饰剂,制备了硫化镉(CdS)纳米粒子.X射线衍射谱表明,产物为立方闪锌矿晶型CdS纳米粒子,其晶粒平均大小为4.38 nm.红外和紫外可见光光谱显示,产物表面吸附有硫脲分子,而且在235 nm处有很强的吸收峰.CdS的荧光光谱显示,样品A在409 nm和520 nm处有2个发射峰,分别对应于激子和缺陷发射;样品B在409 nm处有激子发射峰,而没有缺陷发射峰,这表明表面缺陷基本消失,说明增加硫脲的用量可以很好地修饰CdS纳米粒子的表面.

Cadmium sulfide（CdS） nanoparticles were synthesized using so-gel method.Thiourea was used for the modification of the surface of the CdS nanoparticles.XRD pattern shows that the CdS nanoparticles are consist of zinc blende with average crystal size of 4.38 nm.IR spectrum shows the presence of thiourea molecules on the surface of the CdS nanoparticles and UV-visible spectrum displays the strong peak at 235 nm.Photoluminescence（PL） spectrum of sample A exhibits two peaks at 409 nm and 520 nm,the first is from the exciton recombination and the second is from the surface defects.PL spectrum of sample B displays the only one peak at 409 nm.The absence of the second peak of sample B confirms disappearance of surface defects,indicating that the surfaces of the CdS nanoparticles is well modified by adding more thiourea in the reaction.