Assembling and Disassembling Ag Clusters on Si(111)-(7×7) by Vertical Atomic Manipulation

Abstract

Atomic manipulation has been rarely used in the studies of complex structures and a low temperature requirement usually limits its application. Herein we have demonstrated a vertical manipulation technique to reproducibly and reversibly manipulating Ag atoms on an Si(111)-(7×7) surface by a scanning tunneling microscope tip at room temperature. Simple and complex Ag nanoclusters were assembled and disassembled with a precise control of single Ag atoms, which provided critical information on the size of these nanoclusters. The manipulation showed the growth processes of these Ag clusters and even partly unveiled their atomic structures. This technique can form a fundamental basis for further studies of the Ag/Si(111)-(7×7) system and for fabricating functional nanodevices in various metal-semiconductor systems.

Probing the generalized magicity of Ag nanoclusters constructed on Si(111) by atomic manipulation

“…36 The Ag clusters are prepared by STM vertical atomic manipulation. We take a faulted-HUC (FHUC) of the (7 × 7) reconstruction as a template trap 35 and use a functionalized STM tip to repetitively transfer single Ag atoms elsewhere to this target FHUC to construct the Ag clusters, one Ag atom at a time.…”

“…Consequently, the sizes of the clusters can be obtained by counting the number of the Ag atoms used in the assembly. 36 At room temperature, multiple Ag clusters with the same size as well as with different sizes are fabricated in a local area of the surface for subsequent statistical measurements. Sufficient time is allowed at room temperature for the atoms to relax to their equilibrium positions before the clusters are cooled or heated in situ.…”

Identifying Multiple Configurations of Complex Molecules on Metal Surfaces

“…This technique and their analysis model were soon used in other research, including a report involving Co atoms and CoCu 2 on Cu(111) by J. A. Stroscio and R. J. Celotta,71, 72 Ge dimers on Ge(001) by A. von Houselt et al73 and A. Saedi et al,74 Ag atoms on Si(111)‐ 7 × 7 by K. D. Wang et al,75, 76 as shown in Figure 6. It is worth noting that the TRTS can be used for both molecular diffusion observation and molecular configuration switching.…”

Scanning tunneling microscopy at multiple voltage biases of stable “ring-like” Ag clusters on Si(111)–(7×7)

“…Ming et al recently determined the number of atoms in Ag clusters obtained by deposition at room temperature without annealing [17,18]. While measuring at a bias voltage of + 2 V, they observed three lobes only on clusters with 10 to 13 Ag atoms.…”

“…We present a series of STM images at different bias voltages for the two different "ring-like" clusters. In order to propose a structural model for these clusters, we combined this new insight together with the structure of Au clusters on Si(111)-(7 × 7) studied by Ghose et al [16] as well as the number of Ag atoms determined by comparison with the studies from Ming et al [17,18].…”