Si(111) strained layers on Ge(111): Evidence for c (2 ×4 ) domains
Si(111) strained layers on Ge(111): Evidence for c (2 ×4 ) domains
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Ge(111) 上的 Si(111) 应变层：c (2 ×4 ) 域的证据
DOI：
10.1103/physrevb.96.085401
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发表时间：
2017
影响因子：
3.7
通讯作者：
B. Voigtlander
中科院分区：
文献类型：
--
作者：
R. Zhachuk;J. Coutinho;A. Dolbak;V. Cherepanov;B. Voigtlander
采用扫描隧道显微镜、低能电子衍射和第一性原理计算相结合的方法研究了生长在Ge（111）衬底上的张应变Si（111）层。它示出的层表现出c（2 × 4）域，这是由畴壁沿沿着分开。提出了一种c（2x 4）畴的模型结构，该结构具有较低的形成能，与实验数据吻合较好。我们的计算结果表明，Ge原子很可能取代表面上的悬挂键（剩余原子和吸附原子）的Si原子，从而显着降低表面能和诱导畴壁的形成。实验和计算表明，当表面应变由压应变转变为拉应变时，（111）重构由二聚体-吸附原子-堆垛层错结构转变为吸附原子-堆垛层错结构。
The tensile strained Si(111) layers grown on top of Ge(111) substrates are studied by combining scanning tunneling microscopy, low energy electron diffraction and first-principles calculations. It is shown that the layers exhibit c(2x4) domains, which are separated by domain walls along directions. A model structure for the c(2x4) domains is proposed, which shows low formation energy and good agreement with the experimental data. The results of our calculations suggest that Ge atoms are likely to replace Si atoms with dangling bonds on the surface (rest-atoms and adatoms), thus significantly lowering the surface energy and inducing the formation of domain walls. The experiments and calculations demonstrate that when surface strain changes from compressive to tensile, the (111) reconstruction converts from dimer-adatom-stacking fault-based to adatom-based structures.