Structural, Compositional, and Optical Characterizations of Vertically Aligned AlAs/GaAs/GaP Heterostructure Nanowires Epitaxially Grown on Si Substrate
Structural, Compositional, and Optical Characterizations of Vertically Aligned AlAs/GaAs/GaP Heterostructure Nanowires Epitaxially Grown on Si Substrate
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Si 衬底上外延生长的垂直排列 AlAs/GaAs/GaP 异质结构纳米线的结构、成分和光学表征
DOI：
10.1143/jjap.49.015001
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发表时间：
2010
影响因子：
1.5
通讯作者：
H. Nakano
中科院分区：
文献类型：
--
作者：
Guoqiang Zhang;K. Tateno;H. Gotoh;T. Sogawa;H. Nakano
我们在结构、成分和光学上表征了生长在Si衬底上的垂直排列的AlAs/GaAs/GaP异质结构纳米线（NWs），用于将光学活性材料集成到Si基技术及其带隙工程中。以金胶体纳米颗粒为催化剂，通过气-液-固模式生长NWs。通过交替更换源材料Ga和Al，我们在Si衬底上外延生长的GaP段上生长出具有良好周期性结构和组成的GaAs/AlAs/GaAs/AlAs/GaAs NWs。尽管晶格失配高达4%，但在GaP段上生长的NWs的GaAs段中没有发现晶格失配引起的位错。这是因为NWs具有纳米级直径的特殊柱状结构，因此可以横向松弛并适应高应变。混锌结构的GaP和GaAs段存在层错，而AlAs段为纯纤锌矿晶体结构，没有层错。发现III-V级NWs的层错与层错能和离子性有显著的关系。随着离子性的增加，更容易引入层错，这些NWs往往具有纤锌矿晶体结构。此外，由于GaAs NW表面的表面态导致了高的表面非辐射复合率，裸露的GaAs NW段光致发光的激子发射衰减时间短至30 ps。随着AlGaAs盖层和GaAs外壳层的生长，激子发射衰减时间增加了46倍，表明GaAs段表面具有良好的钝化效果。
We structurally, compositionally, and optically characterize vertically aligned AlAs/GaAs/GaP heterostructured nanowires (NWs) grown on a Si substrate used for the integration of an optically active material into Si-based technology and its band-gap engineering. The NWs were grown using Au colloidal nanoparticles as catalysts via the vapor–liquid–solid mode. By alternately changing the source material between Ga and Al, we grew GaAs/AlAs/GaAs/AlAs/GaAs NWs with a well-controlled periodic structure and composition on a GaP segment, which was epitaxially grown on a Si substrate. No dislocations induced by the lattice mismatch were found in the GaAs segment of the NWs grown on the GaP segment despite a lattice mismatch of as large as 4%. This is because the NWs have a particular columnar structure with nanoscale diameters and can therefore relax laterally and accommodate a high strain. Stacking faults exist in zinc-blende-structured GaP and GaAs segments, while the AlAs segment has a pure wurtzite crystal structure without any stacking faults. It is found that the stacking fault in III–V NWs is significantly dependent on the stacking fault energy and ionicity. With increasing ionicity, stacking faults can be more easily introduced, and these NWs tend to have a wurtzite crystal structure. In addition, owing to the high surface nonradiative recombination rate resulting from the surface states on the GaAs NW surface, the excitonic emission of photoluminescence from the bare GaAs NW segment has a decay time of as short as 30 ps. With the growth of an AlGaAs capping layer and GaAs outer shell layer, the decay time of the excitonic emission increased 46-fold, indicating an excellent passivation effect on the GaAs segment surface.
影响因子：
38.3
作者：
Allen, Jonathan E.;Hemesath, Eric R.;Lauhon, Lincoln J.
通讯作者：
Lauhon, Lincoln J.