González J C, Malachias A, Andrade R-Ribeiro, de Sousa J C, Moreira M V B, de Oliveira A G
Departamento de Física, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Postal Code 702, 30123-970 Belo Horizonte, Brazil.
J Nanosci Nanotechnol. 2009 Aug;9(8):4673-8. doi: 10.1166/jnn.2009.1285.
Direct evidences of enhanced Ga interdiffusion in InAs free-standing nanowires grown at moderate temperatures by molecular beam epitaxy on GaAs (111)B are presented in this work. Scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction measurements in coplanar and grazing incidence geometries show that nominally grown InAs NWs are actually made of an In0.86Ga0.14As alloy. Unlike typical vapor-liquid-solid growth, these nanowires are formed by diffusion-induced growth combined with strong interdiffusion from substrate material. Based on the experimental results, a simple nanowire growth model accounting for the Ga interdiffusion is also presented. This growth model could be generally applicable to the molecular beam heteroepitaxy of III-V nanowires.
本文展示了通过分子束外延在GaAs(111)B上中等温度下生长的InAs独立纳米线中Ga互扩散增强的直接证据。扫描电子显微镜、能量色散X射线光谱以及共面和掠入射几何构型下的X射线衍射测量表明，名义上生长的InAs纳米线实际上由In0.86Ga0.14As合金构成。与典型的气-液-固生长不同，这些纳米线是由扩散诱导生长以及来自衬底材料的强互扩散共同形成的。基于实验结果，还提出了一个考虑Ga互扩散的简单纳米线生长模型。该生长模型通常适用于III-V族纳米线的分子束异质外延。
