One-dimensional diamond nanostructures: Fabrication, properties and applications

Abstract

Diamonds exhibit a unique combination of numerous excellent physical and chemical properties, such as the highest hardness, high Young's modulus, wide bandgap, high carrier mobility, negative electron affinity, and high thermal conductivity. Especially, diamond has attracted significant attention in recent years for its outstanding performance in high-frequency and high-power electronic devices and thermal management. Inheriting the intrinsic physical and chemical properties of diamonds, one-dimensional (1D) diamond nanostructures exhibit many additional properties that are unavailable for bulk diamond or thin films, e.g., large specific surface area, ultrahigh elasticity, and some plasticity, tip effect as well as direct transport for photon or photo-induced carriers. These properties make 1D diamond nanostructures an ideal candidate for applications ranging from micro/nano-electromechanical systems (MEMS/NEMS) to field electron emission, optical, electrochemical, and biological areas. This review will first introduce the development of controlled synthesis methods of 1D diamond nanostructure, including bottom-up chemical vapor deposition growth and top-down selective etching of bulk diamond. Subsequently, we will summarize recent advances in the mechanical, electron field emission, optical, and biological properties of 1D diamond nanostructures and their applications in electron and photon emitter, MEMS, sensing, intracellular delivery, etc.