Structural Characterization of Oleylamine- and Dodecanethiol-Capped Ge 1–x Sn x Alloy Nanocrystals
Structural Characterization of Oleylamine- and Dodecanethiol-Capped Ge 1–x Sn x Alloy Nanocrystals
复制标题
油胺和十二烷硫醇封端的 Ge 1-x Sn x 合金纳米晶体的结构表征
DOI：
10.1021/acs.jpcc.0c11637
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Kauzlarich, Susan M.
中科院分区：
文献类型：
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作者：
Newton, Kathryn A.;Sully, Heather Renee;Bridges, Frank;Carter, Sue A.;Kauzlarich, Susan M.
采用微波辅助加热的方法合成了环氧乙胺包封的ge1 - xsnx纳米晶体。在保持Ge和Sn前驱体浓度不变的情况下，通过改变反应温度，在3.8 ~ 9.3 nm的尺寸范围内获得了Sn含量为13.9±2.1%的ge1 - xsnx纳米晶体。在不影响纳米晶体锡组成的情况下，用十二硫醇取代了环氧乙胺盖层配体。对粉末x射线衍射图的Rietveld细化得到的晶格参数采用维加德定律得到锡的组成。扫描透射电子显微镜提供颗粒大小和形态。在十二硫醇包封的纳米晶体Sn和Ge边缘扩展的x射线吸收精细结构证实了固溶体，拉曼光谱进一步支持了这一观点。1H NMR和FTIR对配体交换前后的表面配体盖层进行了表征。本文报道了用紫外-可见-近红外光谱的tac图分析来确定环氧乙胺和十二烷基硫醇包封的ge1 - xsnx纳米晶体的间接光学带隙。这项工作证明了合成温度对ge1 - xsnx纳米晶体的粒度、组成和结构的影响。
Microwave-assisted heating methods have been used to synthesize oleylamine-capped Ge1–xSnxnanocrystals. By varying the reaction temperature while keeping the Ge and Sn precursor concentrations constant, Ge1–xSnxnanocrystals with Sn compositions of 13.9 ± 2.1% over the 3.8–9.3 nm size range have been achieved. The oleylamine-capping ligand is replaced with dodecanethiol without affecting the Sn composition of the nanocrystals. The Sn composition is obtained from employing Vegard’s law on the lattice parameters obtained from the Rietveld refinement of powder X-ray diffraction patterns. Scanning transmission electron microscopy provides particle size and morphology. Extended X-ray absorption fine structure at the Sn and Ge edges of the dodecanethiol-capped nanocrystals confirms the solid solution, which is further supported by Raman spectroscopy.1H NMR and FTIR are used to characterize the surface ligand capping before and after ligand exchange. Tauc plot analysis of UV–vis–NIR spectra to determine the indirect optical band gap for oleylamine- and dodecanethiol-capped Ge1–xSnxnanocrystals is reported. This work demonstrates the effects of synthesis temperature on the particle size, composition, and structure of Ge1–xSnxnanocrystals.