Bismuth Doping of Germanium Nanocrystals through Colloidal Chemistry
Bismuth Doping of Germanium Nanocrystals through Colloidal Chemistry
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DOI：
10.1021/acs.chemmater.7b02241
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发表时间：
2017-09-12
影响因子：
8.6
通讯作者：
Kauzlarich, Susan M.
中科院分区：
文献类型：
--
作者：
Tabatabaei, Katayoun;Lu, Haipeng;Kauzlarich, Susan M.
纳米锗是一种具有巨大技术应用潜力的材料，掺杂和合金化的Ge纳米晶体（NC）正在被积极考虑。新的合金和成分在胶体合成中是可能的，因为反应是动力学控制的，而不是热力学控制的。大多数V族元素已被证明是Ge中的n型掺杂剂，以增加载流子浓度；然而，从热力学角度来看，Bi 在晶体 Ge 中不具有溶解度。首次采用微波辅助溶液路线合成了 Bi 掺杂 Ge NC。油酰胺封端配体可以被十二烷硫醇取代，而不会损失 Bi。通过粉末X射线衍射和选区电子衍射表明，晶格参数与Bi含量浓度（0.5-2.0 mol%）之间呈正相关。 X 射线光电子能谱、透射电子显微镜 (TEM)、扫描 TEM 和电感耦合等离子体质谱与高达 2 mol% 的 Bi 溶解度一致。 NC 尺寸随着反应中使用的碘化铋量的增加而增加。吸收数据表明Bi掺杂Ge NCs的带隙与NC尺寸一致。这项工作表明，可以通过微波辅助途径将新元素掺杂到 Ge NC 中，掺杂量高达 1-2 mol%，从而增加载流子。胶体化学为开发其他方法无法获得的新材料提供了途径。
Nanogermanium is a material that has great potential for technological applications, and doped and alloyed Ge nanocrystals (NCs) are actively being considered. New alloys and compositions are possible in colloidal synthesis because the reactions are kinetically rather than thermodynamically controlled. Most of the Group V elements have been shown to be n-type dopants in Ge to increase carrier concentration; however, thermodynamically, Bi shows no solubility in crystalline Ge. Bi-doped Ge NCs were synthesized for the first time in a microwave-assisted solution route. The oleylamirie capping ligand can be replaced by dodecanethiol without loss of Bi. A positive correlation between the lattice parameter and the concentration of Bi content (0.5-2.0 mol %) is shown via powder X-ray diffraction and selected area electron diffraction. X-ray photoelectron spectroscopy, transmission electron microscopy (TEM), scanning TEM, and inductively coupled plasma-mass spectroscopy are consistent with the Bi solubility up to 2 mol %. The NC size increases with increasing amount of bismuth iodide employed in the reaction. Absorption data show that the band gap of the Bi-doped Ge NCs is consistent with the NC size. This work shows that a new element can be doped into Ge NCs via a microwave assisted route in amounts as high as 1-2 mol %, which leads to increased carriers. Colloidal chemistry provides an inroad to new materials not accessible via other means.