Abstract: At room temperature, Cd(NO₃)₂ solution was dropped in the quickly stirred aqueous solution consisted of Na₂S and waterglass. After the mixture was stirred for 6h, the powders of nanocrystalline CdS were obtained by careful washing and filtering, which were characterized by XRD, TEM and absorption spectrometer. It was found that the average particle diameter(1.4～3.7nm) of CdS powders is controlled by waterglass concentrations, prevailing crystal system whose particles were wrapped by non-crystal CdS belongs to wurtzite phase and the related optical band gap reaches 3.1eV. It was assumed that the non-crystal CdS wrapped on crystal CdS can result in red-shifted luminescence for absorption spectrum.

Key words: crystal, non-crystal, average particle diameter, optical band gap, absorption spectrum

摘要： 室温下将Cd(NO₃)₂溶液滴加至水玻璃与Na₂S混合溶液中，搅拌6h后经处理得CdS细粉。XRD检测表明它们的主要晶型趋于立方ZnS型，平均粒径为1.4～3.7nm，其颗粒尺寸受水玻璃浓度的控制；TEM检测显示CdS结晶颗粒包裹有非晶态CdS，其CdS粉体呈较好的分散性；光谱分析结果表明所制备纳米CdS的能隙约为3.1eV，吸收光谱所产生的红移荧光现象可能与晶体CdS包裹有非晶CdS有关。

关键词: 晶体, 非晶体, 平均粒径, 能隙, 吸收光谱