image: A schematic diagram of formation and measurement of molecular junctions of oligofluorenes. Oligofluorene molecular wires can be synthesized with high efficiency and high purity, and can be easily incorporated into single molecule circuits under the conditions of solution phase, ambient temperature and pressure. The molecular conductance of newly synthesized oligofluorene molecules was measured by scanning tunneling microscopy based break-junction method. These molecules can be easily integrated into single molecule circuits. Compared with prototype lines with extended π-electronic states, such as oligophenyleneethynylene and oligophenylenevinylene, oligomeric fluorene molecular lines show higher conductivity, and there is a correlation between conductivity trend and the energy gap between the highest occupied molecular orbital and lowest unoccupied molecular orbital. view more
Credit: Bingrun Chen
In a paper to be published in the forthcoming issue in NANO, a group of researchers from the Shenyang Jianzhu University in China provide an overview of single molecule electronic devices, including molecular electronic devices and electrode types. Future challenges to the development of electronic devices based on single molecules are described, in the hopes of attracting more experts from different fields to participate in this research.
How small can computers be in the future? Can you imagine how molecular machines works?
At present, traditional electronic devices based on semiconductor materials will face severe challenges. These challenges are not only technical and technological limitations, but also, more importantly, theoretical limitations. With the rapid development of nanotechnology and in-depth research, great progress has been made in the theory and practice of molecular electronic devices in recent years
Molecular electronic devices are devices that use molecules (including biomolecules) with certain structures and functions to build an ordered system in the molecular scale or supramolecular scale. They make use of the quantum effect of electrons to work, control the behavior of single electrons, and realize the functions of information detection, processing, transmission and storage, such as molecular diodes, molecular memories, molecular wires, molecular field effect transistors and molecular switches.
As a stable quantum system with abundant photoelectric properties, molecules have many electronic transport properties different from semiconductor devices. Molecular electronic devices have the following advantages: (1) small molecular volume, which can improve the integration and operation speed; (2) selecting appropriate components and structures can widely change the electrical properties of molecules; (3) molecules are easy to synthesize, and the required structure can be formed by a self-assembly method; and (4) the molecular scale is on the nanometer scale and has advantages in cost, efficiency, and power consumption.
With the traditional silicon-based electronic devices becoming smaller and smaller, the impact of quantum effect is gradually recognized. The research on molecular electronics has made significant breakthroughs. As more and more excellent characteristics such as potential thermoelectric effects, new thermally induced spin transport phenomena and negative differential resistance are discovered and understood, it is believed that "smaller", "faster" and "cooler" high-tech products will eventually be realized in the future.
However, current research work on molecular devices is still theoretical, and there is still much work to be done in terms of device manufacturing reliability, experimental repeatability, and manufacturing cost. Therefore, the purpose of this review is to attract more experts, scholars and engineers from different fields such as chemistry, physics and microelectronics to participate in this research, so that molecular electronic devices can become a reality as soon as possible.
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This work was supported by the National Nature Science Foundation of China (Grant Nos. 11704263).
Corresponding author for this study is Bingrun Chen, 120333206@qq.com. Ke Xu from Shenyang Jianzhu University is a co-author.
For more insight into the research described, readers are invited to access the paper on NANO.
IMAGE
Caption: A schematic diagram of formation and measurement of molecular junctions of oligofluorenes. Oligofluorene molecular wires can be synthesized with high efficiency and high purity, and can be easily incorporated into single molecule circuits under the conditions of solution phase, ambient temperature and pressure. The molecular conductance of newly synthesized oligofluorene molecules was measured by scanning tunneling microscopy based break-junction method. These molecules can be easily integrated into single molecule circuits. Compared with prototype lines with extended π-electronic states, such as oligophenyleneethynylene and oligophenylenevinylene, oligomeric fluorene molecular lines show higher conductivity, and there is a correlation between conductivity trend and the energy gap between the highest occupied molecular orbital and lowest unoccupied molecular orbital.
Please contact with Bingrun Chen, 120333206@qq.com for usage restrictions on the picture.
NANO is an international peer-reviewed monthly journal for nanoscience and nanotechnology that presents forefront fundamental research and new emerging topics. It features timely scientific reports of new results and technical breakthroughs and publishes interesting review articles about recent hot issues.
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