A big problem with graphene, a super-strong, atom-thick material that could soon be used to build a new generation of thin and flexible electronics, is that it constantly conducts electricity. Electronics need to be able to turn the flow on and off, which is not currently possible with a pure sheet of graphene.
Stanford researchers wrote in Nature Communications Tuesday that they have come up with one of a growing number of alternatives. It might not be as strong or thin as graphene, but the three-atom-thick material they modeled has the unusual feature of being able to switch between two different atomic structures, allowing it to turn the flow of electricity on or off like a light switch.
The material is made from an atom-thick layer of molybdenum, a metal, sandwiched between a tin-like chemical known as tellurium that is already used in solar panels.
Photo courtesy of Karel-Alexander Duerloo.
The two materials form a crystal, which, when pulled apart, forms an insulator to block electricity from flowing. When it is pushed back together, it becomes a semiconductor.
The Stanford team did not make the crystal. So far, it has only been modeled on a computer. But its members hope their work will inspire other scientists to pursue developing it. If they do, it could push forward electronics that are thin and flexible enough to fit around wrists, be woven into clothes and incorporated into everyday objects.
