A team at the Department of Energy’s Oak Ridge National Laboratory and North Carolina State University has found a way to grow narrow ribbons of graphene without the use of metal substrates.
Narrow graphene ribbons can perform as a semiconductor if the ribbons are made with a specific edge shape, but to grow graphene nanoribbons with controlled width and edge structure from polymer precursors, is not a simple task. Previous researchers had used a metal substrate to catalyse a chemical reaction, but the metal substrate suppresses useful edge states and shrinks the desired band gap. The team in this work managed to grow graphene nanoribbons without a metal substrate. Instead, they injected charge carriers that promote a chemical reaction that converts a polymer precursor into a graphene nanoribbon.