Recent developments in black phosphorus transistors

The discovery of graphene has inspired great research interest in two-dimensional (2D) layered nanomaterials during the past decade. As one of the newest members in the 2D layered nanomaterial family, black phosphorus (BP), with puckered structure similar to graphene, has shown great potential in novel nano-electronics owing to its thickness-dependent bandgap. Especially, the unique in-plane anisotropy and high carrier mobility enable BP to be a promising candidate for field-effect transistor (FET) applications. In addition, monolayer or few-layer BP can be combined into van der Waals heterostructures and this opens up a pathway for overcoming existing problems such as impurity scattering and surface degradation or achieving functionalities. In this article, we will review the typical physical and chemical properties of BP and provide an overview of the recent developments in BP-based transistors. In this review, we also discuss the current challenges in BP transistors and future research directions.