Factors influencing the distribution of charge in polar nanocrystals
Factors influencing the distribution of charge in polar nanocrystals
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DOI：
10.1103/physrevb.83.241402
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发表时间：
2011-05
影响因子：
3.7
通讯作者：
P. Avraam;N. Hine;Paul Tangney;P. Haynes
中科院分区：
文献类型：
--
作者：
P. Avraam;N. Hine;Paul Tangney;P. Haynes
我们对纤锌矿结构的砷化镓纳米棒进行了第一性原理计算，以探索决定极性纳米结构中电荷分布的因素。我们发现，纳米棒的偶极矩d的方向和大小，以及它的电场，都敏感地取决于其表面的终止方式，而不是强烈地依赖于底层晶格的自发极化。我们确定了d受表面终止控制的两种物理机制，并且我们证明了纳米棒末端的过剩电荷不是强烈局域的。我们讨论了这些结果对调整纳米晶体的性质以及它们的生长和组装的影响。
We perform first-principles calculations of wurtzite GaAs nanorods to explore the factors determining charge distributions in polar nanostructures. We show that both the direction and magnitude of the dipole moment d of a nanorod, and its electric field, depend sensitively on how its surfaces are terminated and do not depend strongly on the spontaneous polarization of the underlying lattice. We identify two physical mechanisms by which d is controlled by the surface termination, and we show that the excess charge on the nanorod ends is not strongly localized. We discuss the implications of these results for tuning nanocrystal properties, and for their growth and assembly.