A Memristive Element Based on an Electrically Controlled Single‐Molecule Reaction

Abstract

The exponential proliferation of data during the information age has required the continuous exploration of novel storage paradigms, materials, and devices with increasing data density. As a step toward the ultimate limits in data density, the development of an electrically controllable single‐molecule memristive element is reported. In this device, digital information is encoded through switching between two isomer states by applying a voltage signal to the molecular junction, and the information is read out by monitoring the electrical conductance of each isomer. The two states are cycled using an electrically controllable local‐heating mechanism for the forward reaction and catalyzed by a single charge‐transfer process for the reverse switching. This single‐molecule device can be modulated in situ, is fully reversible, and does not display stochastic switching. The I–V curves of this single‐molecule system also exhibit memristive character. These features suggest a new approach for the development of molecular switching systems and storage‐class memories.

The Formation and Conducting Mechanism of Imidazole‐Gold Molecular Junctions

“…Recent experiments have shown that the conductance of single-molecule junctions can be markedly affected by the charging states of the bridging molecule. [17,18] Moreover, they proposed that repeating Im À À Au units are pulled out to bridge the junction during the elongation corresponding to the low conductance features, which still calls for further verifications. Taken together, in order to gain a deep insight into the formation and conducting mechanism of imidazole-based molecular junctions, it is highly desirable to perform first-principles theoretical calculations taking explicitly into account the atomic and charging states of the central imidazole molecule in the junction.…”

“…A series of comparative experiments unambiguously reveal the elimination of the hydrogen atom, but strictly speaking, either an imidazole radical (Im) or an imidazole radical anion (Im − ) bridging the junction has not been clearly identified. Recent experiments have shown that the conductance of single‐molecule junctions can be markedly affected by the charging states of the bridging molecule [17,18] . Moreover, they proposed that repeating Im − −Au units are pulled out to bridge the junction during the elongation corresponding to the low conductance features, which still calls for further verifications.…”

Well-defined Conjugated Macromolecules in Sensing

“…Oligo(arylene ethynylene)s films consist of packed macromolecules with π-conjugated backbone thus exhibit high fluorescence emission which can be altered upon binding of an analyte molecule. OArEs films are an excellent materials for detection of amino acids [61], bacteria [79,80], explosives [34,81,82,85], pH [84], inorganic acids [83], gas [86], digital information [87] or chemicals [88,89]. Usually, the detection of an analyte is based on fluorescence changes, its enhancement or quenching upon binding of the sensed molecule.…”

“…Oligo(phenylene ethynylene)-based sensors have been used to encode digital information [87]. The oligomers ( Table 1, no.…”

“…These two states possess different conductance values and can be used to encode digital information. Reprinted with permission from [87]. Copyright 2020 John Wiley and Sons.…”