摘要
Growth and electronic properties of ultrathin Ga films on Cd(0001) are investigated by low-temperature scanning tunneling microscopy(STM) and density functional theory(DFT) calculations. It is found that Ga films exhibit the epitaxial growth with the pseudomorphic 1×1 lattice. The Ga islands deposited at 100 K show a ramified shape due to the suppressed edge diffusion and corner crossing. Furthermore, the majority of Ga islands reveal flat tops and a preferred height of three atomic layers, indicating the electronic growth at low temperature. Annealing to room temperature leads to not only the growth mode transition from electronic growth to conventional Stranski–Krastanov growth, but also the shape transition from ramified islands to smooth compact islands. Scanning tunneling spectroscopy(STS) measurements reveal that the Ga monolayer exhibits metallic behavior. DFT calculations indicate that all the interfacial Ga atoms occupy the energetically favorable hcp-hollow sites of the substrate. The charge density difference analysis demonstrates that the charge transfer from the Cd substrate to the Ga atoms is negligible, and there is weak interaction between Ga atoms and the Cd substrate. These results shall shed important light on fabrication of ultrathin Ga films on metal substrates with novel physical properties.
作者
李佐
石明霞
姚钢
陶敏龙
王俊忠
Zuo Li;Mingxia Shi;Gang Yao;Minlong Tao;Junzhong Wang(School of Physical Science and Technology,Southwest University,Chongqing 400715,China;School of Science,Guizhou University of Engineering Science,Bijie 551700,China)
基金
Project supported by the National Natural Science Foundation of China (Grant Nos.11874304 and 11574253)。
作者简介
Corresponding Authors:Junzhong Wang,E-mail:jzwangcn@swu.edu.cn。
