Atomistic study of GaSe/Ge(111) interface formed through van der Waals epitaxy
Atomistic study of GaSe/Ge(111) interface formed through van der Waals epitaxy
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DOI：
10.1002/sia.6557
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发表时间：
2018-10
影响因子：
1.7
通讯作者：
T. Yonezawa;T. Murakami;K. Higashimine;A. Fleurence;Y. Oshima;Y. Yamada-Takamura
中科院分区：
文献类型：
--
作者：
T. Yonezawa;T. Murakami;K. Higashimine;A. Fleurence;Y. Oshima;Y. Yamada-Takamura
层状材料可以通过货车德瓦尔斯外延（vdWE）在各种衬底上生长，而不考虑晶格失配。vdWE中薄膜-基底界面的原子学研究由于其作为二维（2D）材料的预期应用而变得越来越重要。在这篇论文中，我们用分子束外延在Ge（111）衬底上生长了GaSe薄膜，并用高角度环形暗场扫描透射电子显微镜（HAADF‐STEM）研究了GaSe/Ge（111）界面。横截面HAADF-STEM观察显示，生长的层主要采用预期的纤锌矿状结构和堆叠，但具有类似于Ga 2Se 3但明显不同的锌-硒-状结构的层以及其他层堆叠序列，局部存在于膜-衬底界面附近。这些结果表明，即使在vdWE中，邻近衬底的生长层中也可能发生结构变化，突出了这种界面对于合成和应用最终薄的2D材料的重要性。
Layered materials can be grown on various substrates through van der Waals epitaxy (vdWE) regardless of lattice mismatch. The atomistic study of the film‐substrate interface in vdWE is becoming increasingly important due to their expected applications as two‐dimensional (2D) materials. In this contribution, we have grown GaSe thin films on Ge(111) substrates by molecular beam epitaxy and studied the GaSe/Ge(111) interface using high‐angle annular dark‐field scanning transmission electron microscopy (HAADF‐STEM). Cross‐sectional HAADF‐STEM observations revealed that the grown layers adopt predominantly the expected wurtzite‐like structure and stacking, but layers with zinc‐blende‐like structure, similar to Ga2Se3 but apparently different, and other layer stacking sequences, exist locally near the film‐substrate interface. These results demonstrate that even in vdWE, structural changes can occur in the grown layers adjacent to the substrate, highlighting the importance of such interface for synthesizing and applying ultimately thin 2D materials.