Directional molecular sliding at room temperature on a silicon runway

Abstract

The design of working nanovehicles is a key challenge for the development of new devices. In this context, 1D controlled sliding of molecules on a silicon-based surface is successfully achieved by using an optimized molecule-substrate pair. Even though the molecule and surface are compatible, the molecule-substrate interaction provides a 1D template effect to guide molecular sliding along a preferential surface orientation. Molecular motion is monitored by STM experiments under ultra-high vacuum at room temperature. Molecule-surface interactions are elucidated by semi-empirical calculations.

Single Molecular Machines on Semiconductor Surfaces

“…Some noisy lines, corresponding to molecular diffusion, are , Vs = 2 V, It = 0.18 nA) and structural models of both (5 × 1) and (7 × 1) reconstructions. Reprinted with permission from [19] observed along the stripes and prove that the movement is guided by a strong template effect of the surface.…”

“…Our work in this domain illustrates well the effect of temperature in self-assembly formation [22][23][24]. Although molecular deposition Reprinted with permission from [19] was performed at room temperature, this thermal energy was sufficient for molecules to overcome diffusion barriers and then form different self-assemblies.…”

“…In order to achieve self-assembly growth, molecules must be free to move across a surface. However, because of the dangling bonds, this movement is not often possible without an [19] external intervention. The idea is to provide some energy to the system (molecule/ surface) in order to overcome molecule-surface interactions and diffusion barriers.…”

“…The study of the template effect of the surface on the adsorption and the diffusion of DETB molecules has been done by Bouju et al [19]. By using a larger unit cell, the SmSi-(7 × 1) instead of a the SmSi-(5 × 1), they shown that the DETB molecules can be adsorbed with a new orientation where their main axis is now perpendicular to the Sm rows (Fig.…”

“…5a) has been used to study the directional molecular sliding on the (8 × 2), the (5 × 1), and the (7 × 1) reconstructions described in Fig. 5 b-e [13,19]. This molecule has been chosen because the distance of 1.64 nm between two Sm rows of SmSi interface corresponds to the length of the molecule.…”