Extremely Low Bias Electron Emitter from Electric Field Induced Reconstructed Tungsten Tip

This report describes a new modification technique of tungsten tip, which results a tip apex capable of emitting electrons at extremely low bias voltages. By employing positive electric field the structure of the tip apex is switched in presence of oxygen followed by freezing out the modified structure at low temperature. Thus modified tip exhibit an extraordinary two orders decrease in applied bias needed for electron emission (from 300V or 210V to as low as 0 to 4V). Electron emission shows good angular confinement with an opening angle of less than 2deg.