The formation of electrically conducting ‘nanoroads’ on atomically thin semiconductor nanosheets enables the integration of electronic components.
Two-dimensional sheets of electronic materials, such as graphene, show promise for practical nanoelectronics applications, including transparent electronic circuits used in electronic displays.
Conducting ‘nanoroads’ on the surface of nanosheets of molybdenum disulfide could underpin integrated electronics on this ultrathin material.
Molybdenum disulfide (MoS2) is of particular interest because, unlike metallic graphene, it is semiconducting, like silicon — the semiconductor that underpins today’s computer technology.
Now, Yongqing Cai from the A*STAR Institute of High Performance Computing in Singapore, with colleagues from China and the United States, has calculated that, by adding hydrogen to a MoS2 surface, regions of the surface can be converted into metallic ‘roads’.
These roads can transport electrical charges between different areas of a MoS2 nanosheet, enabling the fabrication of integrated electronic circuits(1).
Computer chips require both semiconductors and metals. Semiconductors (typically silicon) are the basis for electronic components such as transistors, whereas metals (generally copper or gold) are used for wires that transport electrical charges around a chip. One advantage of using two-dimensional sheets such as MoS2 is that semiconductors and metals can be integrated on the same sheet, facilitating the development of nanoscale computer chips.
For this to become a reality, the semiconducting properties of a MoS2 sheet need to be modified to enable some areas of the sheet to become metallic and hence electrically conducting. Cai dubs these regions ‘nanoroads’.
“The design of conductive nanoroads on two-dimensional nanosheets — in a way that doesn’t compromise their structural integrity — is critical for transporting electrical charges and to create reliable, highly conducting channels for nanoelectronics applications,” explains Cai.
MoS2 has to be modified before it can conduct electricity, since it requires additional atoms to be able to transport electrical charges. The researchers simulated the effects of adding hydrogen atoms to the surface of a MoS2 sheet and found that MoS2 will become metallic in areas where hydrogen atoms bond to its surface.
They showed that adding lines or chains of hydrogen atoms to the surface created metallic strips. The researchers’ calculations reveal that these strips, or nanoroads, are reliable electrical conductors, and, importantly, they do not damage the structure of the underlying sheets.
In terms of practical implementation, the technology already exists for depositing hydrogen on semiconductor nanosheets: hydrogen has been deposited on other two-dimensional sheets, including graphene. Before MoS2 sheets can be used to produce components such as transistors, a method for producing electron-deficient regions needs to be developed. Once this practical challenge has been addressed, the way will be open to successfully using MoS2 in integrated electronic applications.
1. Cai, Y., Bai, Z., Pan, H., Feng, Y. P., Yakobson, B. I. & Zhang, Y.-W. Constructing metallic nanoroads on a MoS2 monolayer via hydrogenation. Nanoscale 6, 1691–1697 (2014).
Lee Swee Heng | Research SEA News
Producing electricity during flight
20.09.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
Solar-to-fuel system recycles CO2 to make ethanol and ethylene
19.09.2017 | DOE/Lawrence Berkeley National Laboratory
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
21.09.2017 | Physics and Astronomy
21.09.2017 | Life Sciences
21.09.2017 | Health and Medicine