Homoepitaxial growth of Bi(111)

Homoepitaxial growth of Bi(111) at temperatures between 80-300 K has been studied using spot profile analyzing low-energy electron diffraction (SPA-LEED) and scanning tunneling microscopy (STM). From the intensity oscillations of the (00)-spot with Bi coverage and the STM topography of two-dimensional (2D) islands at low coverage, a pure 2D nucleation followed by a quasi bilayer-by-bilayer growth mode has been confirmed. The oscillation amplitude decays slowly with coverage, indicating a slow kinetic roughening due to a weak Ehrlich-Schwoebel step edge barrier. From the Arrhenius behavior of the average island separation an intraterrace diffusion barrier of E-d=0.135 eV is estimated. Regularly ordered quasidendritic shape islands reflect an asymmetry in adatom diffusion along the steps and the corners of the islands.