Figure 1

(a) Top: LEED pattern of the semimetallic $\mathrm{Si}(111)(5\times 2)\mathrm{Au}$ surface before Pn deposition. Middle: PEEM image of a submonolayer Pn film grown on top of this surface. The PEEM image shows monolayer high Pn island with a lateral extent of $\sim 20\mu \mathrm{m}$ (light gray on a darker gray background). On top of these islands “daggerlike” second layer Pn islands can be seen to have nucleated before the first layer fully closes; bottom: microbeam LEED pattern obtained on this Pn film. White outlines show 4 reciprocal Pn unit cells. There is no exact azimuthal alignment between the Pn and underlying $(5\times 2)\mathrm{Au}$ lattices. (b) Top: PEEM image of Pn grown on the metallic $\mathrm{Si}(111)(\sqrt{3}\times \sqrt{3})\mathrm{Au}$ surface. Rather than the 2D islands seen in (a), this image shows agglomeration on Pn in 3D islands (dark spots). Bottom: LEEM image of a 3D Pn island, and selective area microbeam LEED patterns obtained on this island. Pn LEED unit cells are outlined in white, and show that the Pn molecules are parallel to the surface. (c) LEED patterns obtained on the clean $\mathrm{Si}(111)(7\times 7)$ surface (top), the epitaxial Bi(001) film (middle), and a monolayer of Pn grown on the Bi(001) surface (bottom). The identical white line segments shown in each pattern show that $6/7{\mathbf{g}}_{\mathrm{Si}}={\mathbf{g}}_{\mathrm{Bi}}=2{\mathbf{g}}_{\mathrm{b},\mathrm{Pn}}$, highlighting the close epitaxial relationships between these three lattices. The Pn LEED unit cell is also shown in the bottom panel. Note: the LEED patterns in panels (a), (b), and (c) are not at the same magnification. (d) Schematic model of the $\mathrm{Bi}(001)/\mathrm{Pn}$ interface as derived from the LEED patterns shown in panel (c).Reuse & Permissions

Figure 2

(a) Tapping-mode AFM image of 3D Pn island grown on $\mathrm{Si}(111)(\sqrt{3}\times \sqrt{3})\mathrm{Au}$. (b) Linescan demonstrating the $\sim 55\mathrm{nm}$ height of the Pn islands.Reuse & Permissions

Figure 3

(a) Vertical height plot along the black line shown in (b). (b) STM image of a monolayer of Pn covering the Bi(001) surface, with a second layer of Pn overgrowing several underlying Bi terraces in the center of the image. (c) High resolution STM image (sample bias $+1.6\mathrm{V}$) showing individual Pn molecules in the first layer. A single Pn unit cell containing 2 Pn molecules (corners and center) is outlined in black. (d) Second layer Pn film (center) on top of a continuous monolayer of Pn on Bi(001). (e) Same layer after application of a 3.6 V pulse to the STM tip, opening a 2 layer deep hole in the Pn island. The bare Bi surface is exposed at the bottom of the hole. (f) Atomic resolution image of underlying Bi lattice. Note the close correspondence between the Pn and Bi lattices by comparing (c) and (f).Reuse & Permissions