【摘要】 本文研究了水溶胶中的CdS半导体超微粒子和有机溶胶中的粒子表面被有机分子化学修饰的CdS超微粒子的光学性质.我们观察到,当粒子尺寸小于5nm时,CdS超微粒子表现出明显的尺寸量子化效应,并指出CdS超微粒子的表面修饰,增强了它们的发光强度,显著地影响了它们的光学性质。更多还原

【Abstract】 In the paper, we report the optical properties of CdS semiconductor ultrafine particles in hydrosols and those of CdS semiconductor ultrafine particles in organosols in which the surfaces of the particles are coated with a layer of organic surfactant molecules. The experimental results show that surface modification of the particles significantly affects their optical properties.CdS hydrosols and organosols were prepared through colloidal chemical method. The particle size and size distribution were determined by TEM and small angk X-ray scattering. The results show that the colloidal particle size is below 10nm.The absorption, excitation and emission spectra of CdS particles in the hydrosols and organosols were measured and discussed, we conclude that when the particle size is less than 5nm,the particles exhibit obvious quantum size effects.The surface modification of the particles effectively removes the surface defects of the particles, and strongly enhances the intensity of interband luminescence. On the other hand, a number of discrete electronic transitions due to quantum confinement effects are observed and explained by the effective mass approximation.更多还原