Electronic Switching of Single Silicon Atoms by Molecular Field Effects

Abstract

We have observed on-off switching of scanning tunneling microscope current flow to silicon adatoms of the Si(111)-(7 x 7) surface that are enclosed within a bistable dimeric corral of self-assembled chlorododecane molecules. These thermally activated oscillations amounted to an order of magnitude change in the current. Theory showed that small changes in molecular configuration could cause alterations in the corralled adatom's electronic energy by as much as 1 eV due to local field effects, accounting for the observed current switching.

Nonlocal Conductance Modulation by Molecules: Scanning Tunneling Microscopy of Substituted Styrene Heterostructures on H-Terminated Si(100)

“…Studies of charge transfer complexes [16] and coupling between functional groups tethered to molecules are more recent [17]. STM transport in adjacent silicon atoms was found to be perturbed by dipole fields due to molecules located elsewhere in the Sið7 Â 7Þ cell [18], and dipole driven ferroelectric assembly of styrene at 7 K has been reported [19].We present experimental (300 K) and theoretical results that show dipole fields produced by substituents bound to aromatic rings on styrene molecules significantly perturb transport characteristics of the host molecules, nearby molecules, and the substrate to which the molecules are attached. For one-dimensional parasubstituted CF 3 -styrene=OCH 3 -styrene molecular heterostructures, transport through molecules at the heterojunction deviates from that of molecules elsewhere within the structure.…”

Single Molecular Machines on Semiconductor Surfaces

“…In this last part, we propose to describe the switching of an adatom (of the surface) induced by molecular adsorption. Polanyi et al [63,64] have investigated the adsorption of chlorododecane on the Si(111)-(7 × 7) surface. These molecules are non-covalently adsorbed on the surface.…”

“…18). [64] When a pair of chlorododecane molecules surrounds a corner hole, a corner adatom, located between jaws of the corral, remains uncovered (Fig. 18b).…”

Electronic Structure of 2H-Tetraphenylporphyrin at Fe/Si (100) Interface

“…It is known that the position and dimension of the molecular assemblies can be tuned and controlled with high precision down to the atomic level on metals [1][2][3] and semiconductors [4][5][6][7]. Developing technologically robust families of adsorbed assemblies on semiconductor surfaces is challenging, especially because the electronic skeleton of molecules is slightly altered after the adsorption [8,9].…”