硫化物半导体超微粒量子尺寸效应的光谱研究

用胶体化学方法在水溶液中制备了纳米硫尺寸硫化物半导体超微粒(CdS、ZnS、PbS、及Bi₂S₃),并用TEM测得超微粒颗粒尺寸小于10nm.本文详细研究了这些硫化物半导体超微粒的量子尺寸效应和光学性质以及制备过程中颗粒形成的化学环境与条件参数的影响。可以观察到它们收光谱及喇曼光谱(CdS)的明显变化。采用合适的表面修饰剂和稳定剂、将溶液的pH控制在适当的范围以及金属离子的过量等,都可使超微粒的吸收光谱明显蓝移并出现结构峰。对于CdS超微粒,其特征共振喇曼峰逐渐减弱直至最后消失。这些都表明了硫化物半导体超微粒尺寸逐渐减小而呈现出明显的量子尺寸效应。

SPECTROMETRIC STUDY OF SIZE QUANTIZATION EFFECTS OF ULTRAFINE SULFIDE SEMICONDUCTOR PARTICLES

Nanometer sized sulfide semiconductor ultrafine particles(CdS,ZnS,PbS and Bi₂S₃)were prepared in aqueous solution by colloidal chemical methods. The particle sizes deter-mined by TEM are below 10 nm. The size quantum effects and optical properties of theresulfide ultrafine particles as well as the influence of the chemical enviroment and conditionparameters of particle formation in the preparation procedure were studied in detail.Significant changes were observed in optical absorption and Raman spectra.When add suitable surface modification agents and stabilizers,keep the solution pH in suitable range, present anexcess of metal ions,it can be found that the absorption edges shift to the shorter wave-length and pronounced structrued peaks exhibit,and characteristic resonance Raman peaks(for CdS particles)gradually decrease,indicating the decrease of particle sizes and clear sizequantum effects.