CdS纳米晶的制备及其荧光研究

Study on Synthesis and Fluorescent Property of CdS Nanocrystals

以醋酸镉、L-半胱氨酸为主要原料,采用水热法制备了尺寸小于10nm、具有强光致荧光的纤锌矿结构CdS半导体纳米晶。水热法可以将晶核形成与晶体生长阶段较好地分开,加之提供的高温熟化条件,可以得到粒度小而均匀、结构良好的纳米晶。用高分辨透射电镜(HRTEM)、XRD对产品的晶体大小、结构进行了详细地表征,分析了影响纳米晶尺寸的因素,用相关性较好的荧光激发与发射光谱研究了硫化镉纳米晶的光致荧光性能。制备的硫化镉(CdS)纳米晶结构良好、粒度均匀、荧光激发专一,最大激发波长在338nm,其发射荧光的波长位于419nm,发射强度大。

The preparation of high-quality CdS semiconductor nanocrystallites of wurtzite structure is described. Crystallites about lOnm in diameter with consistent crystal structure and a high degree of monodispersity were synthesized using cadmium acetate dehydrates and L-cysteine as precursors via hydrothermal method, which separates nucleation stage from growth stage and favors forming of nanocrystals with perfect structure after Ostwald ripening process and sufficiently structural adjustment. High sample quality results showed in sharp fluorescence excitation at 338nm in wavelength and strong photoluminescence emission at 419nm in wavelength. The crystallite structure was characterized by a combination of transmission electron microscopy （TEM）, high resolution transmission electron microscopy （HRTEM）, X-ray powder diffraction （XRD） spectrum. Parameters influencing sizes and photoluminescence are discussed.