Copper substrates were used by researchers from the U.S. Department of Energy's (DOE) Brookhaven National Laboratory and Yale University to synthesize borophene.
Borophene, a two-dimensional atom-thin-sheet of boron, is a chemical element commonly present in fiberglass insulation. It is highly flexible, strong, and lightweight when compared to graphene. Physicists from the U.S. Department of Energy's (DOE) Brookhaven National Laboratory and Yale University have made this development. The newly synthesized borophene on copper substrates had large-area single-crystal domains.
This finds application in electronics, as high-quality single crystals are distributed over large areas of the surface material (substrate) on which they are grown. Ivan Bozovic, co-author and project lead said, “We increased the size of the single-crystal domains by a factor of a million. Large domains are required to fabricate next-generation electronic devices with high electron mobility. Electrons that can easily and quickly move through a crystal structure are key to improving device performance.”
It was predicted that by depositing boron on a particular substrate, a 2-D material similar to graphene could be formed. However, until three years ago, this was not experimentally confirmed. Boron was deposited onto silver substrates under ultrahigh-vacuum conditions through molecular beam epitaxy (MBE), a precisely controlled atomic layer-by-layer crystal growth technique. Then, another group of scientists grew borophene on silver. However, the crystal structure proposed by them was completely different.
Furthermore, researchers are planning to transfer the borophene sheets from the metallic copper surfaces to insulating device-compatible substrates. This will enable scientists to accurately measure resistivity and other electrical properties important for functioning of the device. The main goal in 2-D materials research is to be able to fine-tune the properties of these materials to suit particular applications.