Nb2O5 Nanowires as Efficient Electron Field Emitters

We report a catalyst free method to synthesize single crystal quality Nb2O5 nanowire arrays. Vertically oriented Nb2O5 nanowires directly on Nb foils were synthesized by a thermal oxidation method. The electron field emission (FE) properties of the as-synthesized Nb2O5 nanowires were investigated in detail. Our results showed that the Nb2O5 nanowires are excellent FE emitters with fairly low turn on and threshold field. A remarkably high current density of ∼4 mA/cm2 was achieved at an applied field of 11 V/μm. At moderate applied fields, a continuous and uniform electron emission can be acquired from the Nb2O5 nanowire emitters for a total testing time of 10 h without any noticeable diminution.