Field emission of comb-like chromium disilicide nanowires prepared by an in situ chloride-generated route

Large-area comb-like chromium disilicide (CrSi2) nanowire film has been successfully synthesized on silicon wafer through an in situ chloride-generated route. The sample possesses branch-like nanowires grown out perpendicularly and evenly from both sides of a stem-like microrod, forming 2-fold comb-like hierarchical nanoarchitectures. The formation mechanism of the sample could be understood by a secondary nucleation process occurring on the surface of the firstly formed CrSi2 microrod, followed by epitaxial growth of branch-like nanowires under conditions of proper temperature and sufficient vapor supply in the reaction system. The field-emission behavior of the sample shows a low turn-on field of 5.3–6.5 V/μm at anode-sample distances of 200–400 μm, and agrees well with the conventional Fowler–Nordheim theory. No obvious degradation was observed in a life stability experiment period for over 100 min. The relationship between the field enhancement factor and anode-sample distance follows a universal equation, developed within a two-region field-emission model. The convenient and low-cost preparation of the comb-like CrSi2 nanowires and their remarkable field-emission performance suggest that they can serve as good candidates for field-emission applications.