Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, Bellaterra 08193, Spain.
ACS Nano. 2014 Mar 25;8(3):2290-301. doi: 10.1021/nn405747h. Epub 2014 Mar 5.
An appropriate way of realizing property nanoengineering in complex quaternary chalcogenide nanocrystals is presented for Cu2CdxSnSey(CCTSe) polypods. The pivotal role of the polarity in determining morphology, growth, and the polytypic branching mechanism is demonstrated. Polarity is considered to be responsible for the formation of an initial seed that takes the form of a tetrahedron with four cation-polar facets. Size and shape confinement of the intermediate pentatetrahedral seed is also attributed to polarity, as their external facets are anion-polar. The final polypod extensions also branch out as a result of a cation-polarity-driven mechanism. Aberration-corrected scanning transmission electron microscopy is used to identify stannite cation ordering, while ab initio studies are used to show the influence of cation ordering/distortion, stoichiometry, and polytypic structural change on the electronic band structure.
提出了一种在复杂的四元碲硫属化物纳米晶体中实现纳米工程的合适方法，用于 Cu2CdxSnSey(CCTSe) 多足。证明了极性在确定形态、生长和多型分支机制方面的关键作用。极性被认为是形成初始种子的原因，该种子采用具有四个阳离子极性面的四面体形式。中间的五配位四面体种子的大小和形状的限制也归因于极性，因为它们的外部面是阴离子极性的。最终的多足延伸也由于阳离子极性驱动的机制而分支。使用校正像差的扫描透射电子显微镜来识别硫盐阳离子的有序性，同时使用第一性原理研究来表明阳离子有序/畸变、化学计量和多型结构变化对电子能带结构的影响。
