Doubling down on borophene electronics

Abstract

The discovery of graphene, an atomic-thick carbon layer that can be exfoliated off a bulk graphite, has demonstrated various surprising properties and inspired a fervent quest for other new quasi-two-dimensional materials. Many analogues have been discovered, including borophene, silicene, germanene, stanene, phosphorene, arsenene, antimonene and bismuthine — one-atom-thick sheets of boron, silicon, germanium, tin, phosphorus, arsenic, antimony and bismuth, respectively. Borophene is a prototype for a synthetic two-dimensional (2D) material that does not have bulk layered counterparts. Furthermore, the growth of borophene often requires interfacial coupling with the metal substrate to stabilize its 2D form. Despite realizing rich polymorphs, the synthesized borophene is currently limited to only single atomic layers. Now, writing in Nature Materials, Xiaolong Liu and colleagues report the synthesis of double-layer (DL) borophene, which offers another degree of freedom to tune borophene structures and physical properties for electronic applications.