Chen Han-De, Lin Deng-Sung
Department of Physics, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan.
ACS Omega. 2016 Sep 7;1(3):357-362. doi: 10.1021/acsomega.6b00128. eCollection 2016 Sep 30.
Growth of Ge by molecular beam epitaxy (MBE) on top of the silicene monolayer on the Ag(111) surface results in either a dispersed adlayer or a two-dimensional (2D) ordered structure depending on the silicene phase. Scanning tunneling microscopy (STM) images show that the ordered adsorbed Ge atoms on (3 × 3) domains occupy a position directly on top of down atoms in the buckled silicene layer, similar to the adatom positions on the Ge(111)-c(2 × 8) surface. By contrast, no long-range ordering of Ge adatoms is observed on the domain, possibly partly because of the interference effects of the Ag substrate. Results herein suggest that the deposited Ge atoms tend to build an additional three-dimensional bulk layer on the silicene monolayer and that the growth of the 2D germanene/silicene heterostructure may not be achieved in a straightforward manner.
在Ag(111)表面的硅烯单层之上通过分子束外延(MBE)生长锗，根据硅烯相的不同，会形成分散的吸附层或二维(2D)有序结构。扫描隧道显微镜(STM)图像显示，(3×3)畴上有序吸附的锗原子占据了弯曲硅烯层中向下原子正上方的位置，这与Ge(111)-c(2×8)表面上的吸附原子位置相似。相比之下，在该畴上未观察到锗吸附原子的长程有序，这可能部分是由于银衬底的干涉效应。本文的结果表明，沉积的锗原子倾向于在硅烯单层上构建额外的三维体层，并且二维锗烯/硅烯异质结构的生长可能无法以直接的方式实现。
