Scientists discover 'ripple' in flexible material that could improve electronic properties.
Two-dimensional materials--those either only an atom or layer thick--display a number of interesting properties and could form the foundation for a range of new devices. One of these materials, molybdenum disulfide (M0S2), has shown an unusual flexibility that could make it attractive as a semi-conducting component of bendable electronics.
In a new study from the U.S. Department of Energy's Argonne National Laboratory and Temple University, scientists have discovered an intriguing new behavior in M0S2 at the atomic level as it is stretched and strained, like it would be in an actual flexible device.
After straining a film of the material grown on graphite, the researchers noticed that the formerly two-dimensional sheet of M0S2 would slip, relaxing the strain. This, in turn, formed a rippled pattern at a larger scale that translated into an altered electronic structure within the individual atoms.
"You can think of it like stretching a rubber band," said Argonne nanoscientist Saw-Wai Hla, an author of the study. "After you release the tension, the rubber band snaps back together even more tightly than its initial position."
The ripple pattern remains after the strain is removed and leaves the material looking like a rug that has been bunched up as the material loses its total two-dimensionality. Introducing the ripple through strain could be either deleterious or helpful to the functioning of an actual flexible electronic device, according to Hla, who explained that while an unintentional strain relaxation would likely impair the material, a directed strain response could achieve precisely targeted electronic behavior in M0S2.
A paper based on the study, "The effects of atomic-scale strain relaxation on the electronic properties of monolayer M0S2," appeared in the July 3 issue of ACS Nano. Additional collaborators on the study included Argonne's Yuan Zhang and Temple's Fabrizio Bobba, Xiaoxing Xi, and Maria Iavarone.
Caption: Scanning tunneling microscopy topography of a rippled Mo[S.sub.2] single layer as a result of strain relaxation (bottom). The corresponding dl/dV map at the valence band edge (middle), and the strain map (top) are overlaid.
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|Title Annotation:||INDUSTRY REPORT|
|Date:||Jan 1, 2020|
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