Boron Nanowires for Flexible Electronics and Field Emission

摘要

Development of a rational synthetic method of flexible nanomaterials may enable exciting avenues in both fundamental research and novel device applications. In this paper, flexible boron nanowires have been successfully synthesized on both Si (111) and scanning tunneling microscope (STM) tungsten (W) tips via thermoreduction of boron-oxygen compounds with active metal (magnesium). These as-prepared nanowires, which are structurally uniform and single crystalline, represent good semiconductor at high temperature. Electrical conductivity of these intrinsic nanowires can be improved two orders by introducing doping atoms. Tensile stress measurements demonstrate excellent mechanical property of as-synthesized boron nanowires as well as resistance to mechanical fracture even under a strain of 3percent. Importantly, simultaneous electrical measurement reveals that the corresponding electrical conductance is very robust and remains constant under mechanical strain. Our results can be briefly explained by Mott's variable range hopping (VRH) model. A stable field emission current was also observed from a single boron nanowire. Boron nanostructures with excellent controllability, remarkable mechanical flexibility and field emission characteristics represent promising candidates for flexible nanoelectronic circuits as well as electron emission nanodevices.