Electrochemical Potential‐Driven High‐Throughput Molecular Electronic and Spintronic Devices: From Molecules to Applications

Abstract

Molecules are fascinating candidates for constructing tunable and electrically conducting devices by the assembly of either a single molecule or an ensemble of molecules between two electrical contacts followed by current‐voltage (I‐V) analysis, which is often termed “molecular electronics”. Recently, there has been also an upsurge of interest in spin‐based electronics or spintronics across the molecules, which offer additional scope to create ultrafast responsive devices with less power consumption and lower heat generation using the intrinsic spin property rather than electronic charge. Researchers have been exploring this idea of utilizing organic molecules, organometallics, coordination complexes, polymers, and biomolecules (proteins, enzymes, oligopeptides, DNA) in integrating molecular electronics and spintronics devices. Although several methods exist to prepare molecular thin‐films on suitable electrodes, the electrochemical potential‐driven technique has emerged as highly efficient. In this Review we describe recent advances in the electrochemical potential driven growth of nanometric various molecular films on technologically relevant substrates, including non‐magnetic and magnetic electrodes to investigate the stimuli‐responsive charge and spin transport phenomena.

Molecular Electronics: Creating and Bridging Molecular Junctions and Promoting Its Commercialization

“…[7] At present molecular electronics is not only a burgeoning subfield of nanoscience but also an interdisciplinary area that involves contributions of physicists, chemists, biologists, material scientists, and electronic engineers. [8] In addition to electronic properties (e.g., in diodes, [9] transistors [10] ), charge transport through the molecules can also be controlled optically, mechanically, thermally, magnetically, chemically, and biologically (as shown in Figure 1), leading to the expansion of molecular electronics into optoelectronics (e.g., photoswitches), [11,12] electromechanics (e.g., DNA electromechanical devices), [13,14] thermoelectrics (e.g., Peltier cooler), [15,16] spintronics (e.g., spinterface), [17,18] electrochemistry (e.g., electrochemical transistor), [19,20] and bioelectronics (e.g., DNA sequencing), [21,22] respectively.…”

Flexible Molecular Electrochromic Devices Run by Low‐Cost Commercial Cells

“…[13][14][15][16][17] Organic materials show promising solution-processable; therefore, their homogeneous and desired thickness of thin films can be prepared by employing relatively straightforward techniques like drop casting, spin coating, and electrografting allowing to form homostructure to heterostructures highly desirable for suitable electrochromic device fabrication. [18,19] Viologens, among the electrochromic organic materials have considered the utmost attention due to their ease of chemical structures control and modification, tunable optoelectronic properties, wider ranges of thermal stability, bistable redox states, room temperature solubility, air-stability, large-area surface coating and easy characterization, can withstand larger electrochemical potential window, coloration both in solution and solid-state, and long-range charge transport ability. [13,20,21] Depending on the substituents, viologens may exist in three distinct redox forms: dication (pale yellow/red-colored or colorless), mono-radical-cation (violet-blue/green), and diradical (generally colorless).…”

Chemical Approach Towards Broadband Spintronics on Nanoscale Pyrene Films

“…So far, Few conjugated polymers and organic molecules have been studied for spin transport through spin pumping and inverse spin Hall effect (ISHE), but with the weaker interfaces where molecules are adsorbed either drop‐casted or spin‐coated methods [24–26,35–37] . Electrochemical (E‐Chem) method using aryl diazonium salts is considered the versatile and widespread approach as it provides stable, robust, covalent interfaces at electrode‐molecule layers, fast‐forming, controllable thickness, even heterostructures, and well‐ordered molecular films can be prepared on diverse substrates within minutes with low roughness [38–43] . Pyrene, popularly known as ′fruit fly′ to the photochemists, is a fused‐four benzene ring with higher geometric symmetry of point group of D 2h , and its interesting electronic properties arise due to delocalization of π electrons, well‐explored in organic electronics, field‐effect transistors, photovoltaics, and memory devices [44–48] .…”