Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801-3080, USA.
J Phys Condens Matter. 2011 Sep 14;23(36):365302. doi: 10.1088/0953-8984/23/36/365302. Epub 2011 Aug 25.
We report on the preferred trilayer growth of indium films on Si(111) studied by angle-resolved photoemission spectroscopy. By employing an interfactant and optimized annealing conditions, the kinetic constraint on the In atoms due to the substrate is greatly reduced and 'electronic growth'-where film morphology is controlled by the quantized electronic structure of the film-can be achieved at low coverage. Our photoemission spectra reveal that films of 4 ML (monolayers) and 7 ML thicknesses are energetically favored due to a lower surface energy, as confirmed by theoretical calculations. A detailed comparison of the photoemission spectra between In films grown on the In-√3 × √3/Si(111) surface and those on the Si(111) 7 × 7 surface shows that the √3 × √3 interfactant is a better template for growing In films at low coverage and effectively reduces the electronic coupling between the film and the substrate. In addition, the observed band structures of In films are in reasonable agreement with first-principles calculations and suggest that In films grown on the √3 × √3 interfactant might already be close to the bulk-like body-centered tetragonal structure at around 10 ML.
我们报告了在 Si(111)上通过角分辨光发射光谱研究的首选三层铟膜的生长。通过使用界面活性剂和优化的退火条件，可以大大降低衬底对 In 原子的动力学限制，并且可以在低覆盖率下实现“电子生长”-其中薄膜形态由薄膜的量子电子结构控制。我们的光发射光谱表明，由于表面能较低，4 ML（单层）和 7 ML 厚度的薄膜在能量上更有利，这得到了理论计算的证实。在 In 薄膜生长在 In-√3×√3/Si(111)表面和 Si(111)7×7 表面上的光发射光谱之间的详细比较表明，√3×√3 界面活性剂是在低覆盖率下生长 In 薄膜的更好模板，并有效地降低了薄膜和衬底之间的电子耦合。此外，观察到的 In 薄膜的能带结构与第一性原理计算吻合较好，表明在√3×√3 界面活性剂上生长的 In 薄膜在大约 10 ML 时可能已经接近体心四方结构。
