Evolution of Self-Assembled ZnTe Magic-Sized Nanoclusters
Evolution of Self-Assembled ZnTe Magic-Sized Nanoclusters
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自组装 ZnTe 魔幻尺寸纳米团簇的演化
DOI：
10.1021/ja509782n
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Tijana Rajh
中科院分区：
文献类型：
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作者：
Jun Zhang;Clare Rowl;Yuzi Liu;Hui Xiong;Soongu Kwon;Elena Sheychenko;Richard D Schaller;Vitali B. Prakapenka;Sergey Tkachev;Tijana Rajh
以多碲化物为碲前驱体，通过简单地改变反应温度和时间，在一锅反应中获得了三个家族的ZnTe纳米团簇。不同的ZnTe MSNCs由于其不同的结构、簇大小和偶极-偶极相互作用而表现出不同的自组装或聚集行为。最小的ZnTe MSNCs家族（F323）没有显示出晶体结构，因此组装成层状三角形板。连续加热合成的ZnTe F323组件导致形成具有wurzite结构的ZnTe F398 MSNCs，并伴随转变成沿⟨002⟩方向组织纳米簇的层状矩形组件。进一步退火组装的片状矩形ZnTe F398，使MSNCs在各个方向上充分组织，并形成更大的ZnTe F444 NCs，这些NCs自发形成超薄纳米线，遵循定向附着机制。事实上，控制ZnTe超薄纳米线尺寸分布的关键是ZnTe F398 MSNCs的生长机理；也就是说，与连续生长机制相比，阶梯生长机制可以形成更均匀的纳米线。由于F398前驱体的纤锌矿结构，ZnTe纳米线的产率很高。瞬态吸收（TA）测量表明，尽管这三个家族的晶体结构不同，但它们都具有光生电子的超快动力学。
Three families of ZnTe magic-sized nanoclusters (MSNCs) were obtained exclusively using polytellurides as a tellurium precursor in a one-pot reaction by simply varying the reaction temperature and time only. Different ZnTe MSNCs exhibit different self-assembling or aggregation behavior, owing to their different structure, cluster size, and dipole–dipole interactions. The smallest family of ZnTe MSNCs (F323) does not reveal a crystalline structure and as a result assembles into lamellar triangle plates. Continuous heating of as synthesized ZnTe F323 assemblies resulted in the formation of ZnTe F398 MSNCs with wurzite structure and concomitant transformation into lamellar rectangle assemblies with the organization of nanoclusters along the ⟨002⟩ direction. Further annealing of ZnTe F398 assembled lamellar rectangles leads to full organization of MSNCs in all directions and formation of larger ZnTe F444 NCs that spontaneously form ultrathin nanowires following an oriented attachment mechanism. The key step in control over the size distribution of ZnTe ultrathin nanowires is, in fact, the growth mechanism of ZnTe F398 MSNCs; namely, the step growth mechanism enables formation of more uniform nanowires compared to those obtained by continuous growth mechanism. High yield of ZnTe nanowires is achieved as a result of the wurzite structure of F398 precursor. Transient absorption (TA) measurements show that all three families possess ultrafast dynamics of photogenerated electrons, despite their different crystalline structures.