Self-catalyzed, pure zincblende GaAs nanowires grown on Si(111) by molecular beam epitaxy
Self-catalyzed, pure zincblende GaAs nanowires grown on Si(111) by molecular beam epitaxy
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DOI：
10.1103/physrevb.82.035302
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发表时间：
2010-07-02
影响因子：
3.7
通讯作者：
Zeze, Dagou
中科院分区：
文献类型：
--
作者：
Cirlin, G. E.;Dubrovskii, V. G.;Zeze, Dagou
我们报道了直接在Si（111）衬底上生长相干砷化镓纳米线的无au分子束外延。在初始生长阶段，在天然氧化层的开口中形成的液态Ga液滴催化了生长。透射电镜研究表明，无论纳米线的直径（70-80 nm）和生长温度范围（560-630℃）如何，纳米线都是单晶，沿其长度具有锌闪锌矿结构（除了Ga液滴下方的薄纤锌矿区域）。我们将观察到的相纯度归因于液态Ga比Au-Ga合金的表面能低得多，这使得三线形核在能量上不利。生长催化剂转变为具有较低能量的液态金属，抑制了（更常见的）表面高能基础上纤锌矿核的形成。这些结果为在硅上制备化学纯净、无堆叠缺陷的III-V化合物锌闪锌矿纳米线提供了一种独特的方法。
We report on the Au-free molecular beam epitaxy growth of coherent GaAs nanowires directly on Si(111) substrates. The growth is catalyzed by liquid Ga droplets formed in the openings of a native oxide layer at the initial growth stage. Transmission electron microscopy studies demonstrate that the nanowires are single crystals having the zincblende structure along their length (apart from a thin wurtzite region directly below the Ga droplet), regardless of their diameter (70-80 nm) and the growth temperature range (560-630 degrees C). We attribute the observed phase purity to a much lower surface energy of liquid Ga than that of Au-Ga alloys, which makes triple line nucleation energetically unfavorable. The change in growth catalyst to a liquid metal with a lower energy suppresses the (more usual) formation of wurtzite nuclei on surface energetic grounds. These results can provide a distinct method for the fabrication of chemically pure and stacking-fault-free zincblende nanowires of III-V compounds on silicon.