Shot Noise of High Current Electron Field Emission

Abstract

Summary form only given. This paper presents the importance of space charge effects on the shot noise for electron field emission, in classical, quantum, and relativistic regimes. The Fano factor (which characterizes the reduction of shot noise power from the Schottky shot noise for a thermionic emitter) is computed in each regime. The value of Fano factor is found to be enhanced substantially, when space charge effects are included over a wide range of gap spacing and applied voltage at various work functions. In quantum regime with gap spacing in nanometer scale between cathode and anode, decreasing gap spacing D or work function Phi <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">WF</sub> or temperature will reduce the Fano factor, thus more shot noise reduction. In relativistic regime, where an extremely large bias is applied across a large gap, we will have less shot noise reduction due to relativistic effects as compared to the classical regime.