Two-dimensional sheets of electronic materials show promise for practical nanoelectronics

Jul 02, 2014
Nanotechnology: Paving the way for electronic applications
Conducting ‘nanoroads’ on the surface of nanosheets of molybdenum disulfide could underpin integrated electronics on this ultrathin material. Credit: chuyu/iStock/Thinkstock

Two-dimensional sheets of electronic materials, such as graphene, show promise for practical nanoelectronics applications, including transparent electronic circuits used in electronic displays. 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 .

Computer chips require both and metals. Semiconductors (typically silicon) are the basis for 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 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.

Explore further: Researchers find a way to integrate two two-dimensional materials into a single electronic device

More information: 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). dx.doi.org/10.1039/c3nr05218d

add to favorites email to friend print save as pdf

Related Stories

High-performance MoS2 field-effect transistors

Jun 13, 2014

A team of researchers from Purdue University, SEMATECH and SUNY College of Nanoscale Science and Engineeringwill present at the 2014 Symposium on VLSI Technology on their work involving high-performance molybdenum disulfide ...

Auto lubricant could rev up medical imaging

Aug 05, 2013

Engineers at the University of California, Berkeley, have built a device that could speed up medical imaging without breaking the bank. The key ingredient? An engine lubricant called molybdenum disulfide, ...

Scientists probe the next generation of 2-D materials

Apr 03, 2014

As the properties and applications of graphene continue to be explored in laboratories all over the world, a growing number of researchers are looking beyond the one-atom-thick layer of carbon for alternative materials that ...

Atomic-scale catalysts may produce cheap hydrogen

Jan 22, 2014

Researchers at North Carolina State University have shown that a one-atom thick film of molybdenum sulfide (MoS2) may work as an effective catalyst for creating hydrogen. The work opens a new door for the pr ...

Recommended for you

Tiny graphene drum could form future quantum memory

Aug 28, 2014

Scientists from TU Delft's Kavli Institute of Nanoscience have demonstrated that they can detect extremely small changes in position and forces on very small drums of graphene. Graphene drums have great potential ...

Graphene reinvents the future

Aug 27, 2014

For many scientists, the discovery of one-atom-thick sheets of graphene is hugely significant, something with the potential to affect just about every aspect of human activity and endeavour.

User comments : 0