Transition from Au to pseudo-Ga catalyzed growth mode observed in GaAs nanowires grown by molecular beam epitaxy
Transition from Au to pseudo-Ga catalyzed growth mode observed in GaAs nanowires grown by molecular beam epitaxy
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DOI：
10.1103/physrevb.85.245450
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发表时间：
2012-06
影响因子：
3.7
通讯作者：
M. Soda;A. Rudolph;D. Schuh;J. Zweck;D. Bougeard;E. Reiger
中科院分区：
文献类型：
--
作者：
M. Soda;A. Rudolph;D. Schuh;J. Zweck;D. Bougeard;E. Reiger
我们调查的Ga浓度的催化剂液滴和通过分子束外延生长的单个GaAs纳米线，使用Au作为催化剂材料的晶体结构之间的相关性。通过postgrowth分析的Ga含量的催化剂液滴在生长过程中估计和所观察到的纳米线的晶体结构。根据Ga的浓度，我们观察到从典型的Au催化的伪Ga辅助纳米线生长的过渡：纳米线与低Ga浓度的催化剂液滴在生长过程中主要形成纤锌矿晶体结构。对于Ga浓度高于75 at. %，我们称之为伪Ga辅助生长模式，由于催化剂的降低的液滴表面能，形成锌掺杂链段的可能性大大提高。
We investigate the correlation between the Ga concentration of the catalyst droplet and the adopted crystal structure of individual GaAs nanowires grown by molecular-beam epitaxy using Au as a catalyst material. Through a postgrowth analysis the Ga content of the catalyst droplet during growth is estimated and related to the observed crystal structure of the nanowires. Depending on the Ga concentration, we observe a transition from typical Au catalyzed to pseudo-Ga assisted nanowire growth: Nanowires with low Ga concentration of the catalyst droplet during growth form predominantly wurtzite crystal structures. For Ga concentrations higher than 75 at. %, which we refer to as the pseudo-Ga assisted growth mode, the probability to form zinc-blende segments is strongly enhanced owing to the reduced droplet surface energy of the catalyst.