New 2-D material better than graphene?
Post Date: 06 May 2014 Viewed: 919
Scientists have found a two-dimensional, self-assembling material whose properties are very similar to graphene, but with some distinct advantages, and it may be used to produce solar cells or transistors.
Researchers have been working to harness the unusual properties of the so-called 'wonder-material' graphene, a two-dimensional sheet of carbon atoms.
But graphene lacks one important characteristic that would make it even more useful: a property called a bandgap, which is essential for making devices such as computer chips and solar cells.
Now, researchers at Massachusetts Institute of Technology (MIT) and Harvard Universityhave found the two-dimensional material with similar properties to graphene but the material naturally has a usable bandgap.
The new material, a combination of nickel and an organic compound called HITP, also has the advantage of self-assembly.
Its constituents naturally assemble themselves, a 'bottom-up' approach that could lend itself to easier manufacturing and tuning of desired properties by adjusting relative amounts of the ingredients.
The new compound shares graphene's perfectly hexagonal honeycomb structure. The multiple layers of the material naturally form perfectly aligned stacks, with the openings at the centres of the hexagons all of precisely the same size, about 2 nanometres (billionths of a metre) across.
In initial experiments, the researchers studied the material in bulk form, rather than as flat sheets.
MIT assistant professor of chemistry Mircea Dinca said that makes the current results - including excellent electrical conductivity - even more impressive, since these properties should be better yet in a 2-D version of the material.
Also, this is just the first of what could be a diverse family of similar materials built from different metals or organic compounds, researchers said.
Now, we have an entire arsenal of organic synthesis and inorganic synthesis that could be harnessed to tune the properties, with atom-like precision and virtually infinite tunability, according to Dinca.
Such materials, Dinca said, might ultimately lend themselves to solar cells whose ability to capture different wavelengths of light could be matched to the solar spectrum, or to improved supercapacitors, which can store electrical energy until it's needed.
The research was published in the Journal of the American Chemical Society.