That would make the material known as borophene a candidate for plasmonic and photonic devices like biomolecule sensors, waveguides, nanoscale light harvesters and nanoantennas. The researchers used a computational modeling technique called density functional theory to test plasmonic behavior in three types of free-standing borophene. The material's baseline crystal structure is a grid of triangles -- think graphene but with an extra atom in the middle of each hexagon.
The lab studied models of plain borophene and two polymorphs, solids that incorporate more than one crystalline structure that are formed when some of those middle atoms are removed. Their calculations showed triangular borophene had the widest emission frequencies, including visible light, while the other two reached near-infrared.
The researchers said their results present the interesting possibility of manipulating data at subdiffraction wavelengths.
"If you have an optical signal with a wavelength that's larger than an electronic circuit of a few nanometers, there's a mismatch," she said. "Now we can use the signal to excite plasmons in the material that pack the same information (carried by the light) into a much smaller space. It gives us a way to squeeze the signal so that it can go into the electronic circuit."