CdTe魔尺寸纳米晶的合成及其生长机理研究

发布时间：2018-07-24 11:18

【摘要】：不同于半导体常规纳米晶(RNCs),魔尺寸纳米晶(MSNCs)由于其精确的结构及超窄的带边荧光发射引起了广泛关注。然而MSNCs的合成常为不同种类的MSNCs和RNCs的掺杂混合,这使得高纯度、单一尺寸的MSNCs的合成往往十分困难。作者以醋酸镉和三辛基碲化膦为镉前驱体和碲前驱体,长链烷基酸为表面配体,利用高温热注的方法在1-十八烯中成功合成了两种单一尺寸的CdTe MSNCs。实验结果表明,适当链长的配体酸及相对较低的酸量是抑制RNCs生长,合成单一尺寸CdTe MSNCs的关键。反应温度很大程度上决定了生成的MSNCs的尺寸。采用TEM、EDX、XPS和XRD分析了所合成的CdTe MSNCs的形貌、组成及结构,结果显示其呈现为均一的点状形貌、且具有富镉表面的纤锌矿型结构。通过对升温处理过程中CdTe MSNCs所呈现出来的非连续生长模式进一步分析,提出一种类似Ostwald ripening的生长机制,即部分的CdTe MSNCs在高温下直接分解成单体,沉积在另一部分CdTe MSNCs上,使其"跳跃式"地生长成了尺寸更大的MSNCs。
[Abstract]:Different from conventional semiconductor nanocrystalline (RNCs), nanocrystalline (MSNCs) has attracted much attention due to its precise structure and ultra-narrow edge fluorescence emission. However, the synthesis of MSNCs is usually mixed with different kinds of MSNCs and RNCs, which makes it difficult to synthesize high purity and single size MSNCs. Using cadmium acetate and trioctyl phosphine telluride as precursors of cadmium and tellurium and long chain alkyl acid as surface ligands, two kinds of single size CdTe MSNCs were successfully synthesized in 1-octadecene by high temperature thermal injection. The experimental results show that the proper ligand length and relatively low acid content are the key factors to inhibit the growth of RNCs and to synthesize a single size CdTe MSNCs. The reaction temperature largely determines the size of the generated MSNCs. The morphology, composition and structure of the synthesized CdTe MSNCs were analyzed by XRD and EDX XPS. The results showed that the CdTe MSNCs showed a uniform point shape and a wurtzite structure rich in cadmium. By further analyzing the discontinuous growth pattern of CdTe MSNCs during heating treatment, a growth mechanism similar to Ostwald ripening is proposed, in which part of CdTe MSNCs is directly decomposed into monomers at high temperature and deposited on the other part of CdTe MSNCs. Makes it "jump" to grow into a larger size MSNCs.
【作者单位】：四川大学原子与分子物理研究所;
【基金】：国家自然科学基金资助项目(21573155)
【分类号】：O614.242;TB383.1

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