Determining the work function of a carbon-cone cold-field emitter by in situ electron holography

作者：de Knoop Ludvig^*; Houdellier Florent; Gatel Christophe; Masseboeuf Aurelien; Monthioux Marc; Hytch Martin

来源：Micron, 2014, 63: 2-8.

DOI：10.1016/j.micron.2014.03.005

• In situ TEM
• Field emission of carbon
• Electron holography
• Finite element modeling

Cold-field emission properties of carbon cone nanotips (CCnTs) have been studied in situ in the transmission electron microscope (TEM). The current as a function of voltage, i(V), was measured and analyzed using the Fowler-Nordheim (F-N) equation. Off-axis electron holography was employed to map the electric field around the tip at the nanometer scale, and combined with finite element modeling, a quantitative value of the electric field has been obtained. For a tip-anode separation distance of 680 nm (measured with TEM) and a field emission onset voltage of 80V, the local electric field was 2.55 V/nm. With this knowledge together with recorded i(V) curves, a work function of 4.8 +/- 0.3 eV for the CCnT was extracted using the F-N equation.

• 出版日期2014-8