Simultaneous Selective Area Growth of Wurtzite and Zincblende Self-Catalyzed GaAs Nanowires on Silicon
Simultaneous Selective Area Growth of Wurtzite and Zincblende Self-Catalyzed GaAs Nanowires on Silicon
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DOI：
10.1021/acs.nanolett.1c00349
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发表时间：
2021-04-05
期刊：
影响因子：
10.8
通讯作者：
Morral, Anna Fontcuberta, I
中科院分区：
文献类型：
--
作者：
Dubrovskii, Vladimir G.;Kim, Wonjong;Morral, Anna Fontcuberta, I
选择性区域外延是获得可再生纳米材料的主流方法。与之对应的是，自组装允许它们在不需要昂贵的衬底准备的情况下生长，但缺点是定位不受控制。我们提出了一种混合的方法，其中自组装被限制在图案化的硅衬底上的减少的区域。虽然纳米线的直径分布很广，但我们注意到晶体相主要是二元出现的。在同一生长过程中，自催化的GaAs纳米线以纤锌矿或闪锌矿的形式形成。令人惊讶的是，较粗的纳米线是纤锌矿，较细的纳米线是闪锌矿，而通常的观点预测的是相反的趋势。我们将这一现象与表面扩散引入的Ga原子有关，从而导致了不同的Ga液滴接触角。我们在无Au的方法中展示了直径达200 nm的纤锌矿相，这是我们目前所知尚未实现的。
Selective area epitaxy constitutes a mainstream method to obtain reproducible nanomaterials. As a counterpart, self-assembly allows their growth without costly substrate preparation, with the drawback of uncontrolled positioning. We propose a mixed approach in which self-assembly is limited to reduced regions on a patterned silicon substrate. While nanowires grow with a wide distribution of diameters, we note a mostly binary occurrence of crystal phases. Self-catalyzed GaAs nanowires form in either a wurtzite or zincblende phase in the same growth run. Quite surprisingly, thicker nanowires are wurtzite and thinner nanowires are zincblende, while the common view predicts the reverse trend. We relate this phenomenon to the influx of Ga adatoms by surface diffusion, which results in different contact angles of Ga droplets. We demonstrate the wurtzite phase of thick GaAs NWs up to 200 nm in diameter in the Au-free approach, which has not been achieved so far to our knowledge.