Epitaxial growth of gold on H-Si(111): the determining role of hydrogen evolution.
Epitaxial growth of gold on H-Si(111): the determining role of hydrogen evolution.
复制标题
金在 H-Si(111) 上的外延生长：析氢的决定作用。
作者：
P. Prodhomme;S. Warren;R. Cortès;H. F. Jurca;F. Maroun;P. Allongue
用原子力显微镜和X射线衍射研究了在酸性电解液中，H-端Si（111）上金电沉积的电位依赖性。发现Au膜（≤66单层（ML）≈16 nm）为（111）取向，与Si（111）表面晶格呈强外延，两个面内取向相隔180°。存款形态受沉积电位控制，可以是岛状或原子级平坦。平坦的形态伴随着相对于Si体晶格的180°旋转的Au平面的优先生长，其发生在发生析氢反应的电势下。在Si（111）上获得超平的Au层与通常观察到的半导体上电沉积膜的岛状形态形成对比。这种行为进行了讨论的成核与析氢反应（HER）和增强的Au吸附原子迁移率由该反应引起的。
The potential dependence of gold electrodeposition on H-terminated Si(111) is studied in acidic electrolyte by means of atomic force microscopy and X-ray diffraction. The Au films (≤66 monolayers (ML)≈16 nm) are found to be (111)-oriented and in strong epitaxy with the Si(111) surface lattice, with two in-plane orientations separated by 180°. The deposit morphology is controlled by the deposition potential and can be islandlike or atomically flat. The flat morphology is accompanied by a preferential growth of 180°-rotated Au planes with respect to the Si bulk lattice which takes place at potentials where the hydrogen evolution reaction occurs. Obtaining ultraflat Au layers on Si(111) contrasts with the commonly observed islandlike morphology of electrodeposited films on semiconductors. This behavior is discussed in terms of a nucleation coupled with hydrogen evolution reaction (HER) and an enhanced Au adatom mobility induced by this reaction.