Critical thickness and radius for axial heterostructure nanowires using finite-element method.
Critical thickness and radius for axial heterostructure nanowires using finite-element method.
复制标题
DOI：
10.1021/nl900055x
复制
发表时间：
2009-03
期刊：
影响因子：
10.8
通讯作者：
H. Ye;P. Lu;Zhongyuan Yu;Yuxin Song;Donglin Wang;Shumin Wang
中科院分区：
文献类型：
--
作者：
H. Ye;P. Lu;Zhongyuan Yu;Yuxin Song;Donglin Wang;Shumin Wang
采用有限元方法模拟了生长在柔性平台衬底上的异质结构纳米线。临界厚度是根据总能量平衡法计算的。模拟了由第一对错配位错产生的与初始相干应变场相偏移的应变场。采用局部残余应变来计算总残余应变能。三维模型表明，存在一个与半径相关的临界厚度，在此厚度以下不会产生错配位错。此外，当半径小于某些临界值时，该临界厚度变为无穷大。模拟结果与实验数据吻合较好。与忽略初始相干应变场与位错诱发应变场相互作用的先前模型相比，本文的临界半径更小。
Finite-element methods are used to simulate a heterostructured nanowire grown on a compliant mesa substrate. The critical thickness is calculated based on the overall energy balance approach. The strain field created by the first pair of misfit dislocations, which offsets the initial coherent strain field, is simulated. The local residual strain is used to calculate the total residual strain energy. The three-dimensional model shows that there exists a radius-dependent critical thickness below which no misfit dislocations could be generated. Moreover, this critical thickness becomes infinity for a radius less than some critical values. The simulated results are in good agreement with the experimental data. The critical radius from this work is smaller than that obtained from previous models that omit the interaction between the initial coherent strain field and the dislocation-induced strain field.