Atomic‐ and molecular‐scale devices and systems for single‐molecule electronics

Abstract

Present-day electronic technology, based to a large extent on silicon fabricated devices, is surely approaching size limitations arising from quantum effects. The effort to achieve rapid development of electronic devices requires implementation of entirely new ideas that will allow existing technological constraints to be overcome. Among a wide range of concepts, utilization of single organic molecules, acting as active blocks performing logic operations, appears as one of the most appealing and is based on the state-of-the-art use of modern nanotechnology. In this short review, we offer a selection of recent experiments addressing milestones of single-molecule computing devices technology. Along with discussion of the latest achievements in atomic-and molecular-scale technologies, we discuss their future perspectives, challenges, and still unsolved issues standing in the way of practical implementation of single-molecule devices.Concept of a single-molecule electronic device. The molecule is equipped with various functional groups responsible for logic operations and bonding to an underlying surface and metallic nanoelectrodes. The monomolecular nanodevice is deposited on a thin buffer layer assuring the decoupling from a (semi-)conducting substrate.

Characterization of PTCDA nanocrystals on Ge(001):H-(2×1) surfaces

“…One may also think on tuning interactions of adsorbed molecules with underlying surface in order to minimize its influence, say to decouple molecule from the substrate. In this context several strategies have been proposed so far [4]. For the purpose of the presented study it is convenient to focus on methods based on formation of an ultrathin buffer layer to assure the decoupling.…”

Atomic scale fabrication of dangling bond structures on hydrogen passivated Si(001) wafers processed and nanopackaged in a clean room environment

“…As the minimum feature size of such devices decreases, new challenges concerning the fabrication technologies and design rules have to be overcome. For the manufacturing of nanometer-scale or even smaller devices, one ultimate solution implies the creation of silicon dangling bond (DB) circuits and connections through the scanning tunneling microscope (STM) desorption of hydrogen atoms on a hydrogenated silicon surfaces [1][2][3][4][5]. A reconstructed and atomically flat surface like Si(0 0 1):H is then required, as it can provide regular and aligned atomic rows and would thus be an ideal platform for STM-based lithography [6][7][8][9].…”

Nonlinear optical response of photochromic azobenzene-functionalized self-assembled monolayers

“…8,10,13,14 Regarding the actual implementation of photonic and optoelectronic devices based on molecular switches, the common requirement for accessing the respective molecular functionality is an immobilization strategy which preserves the photochromism of the molecules. Among the various existing strategies regarding this goal, 22 physisorbed systems are well-studied but of rather academic interest. In these systems the switching ability is often suppressed and very small cross sections (i.e., low switching efficiencies) have been observed.…”