Method for measuring work function
US7508216B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 14, 2006 |
| Grant date | Mar 24, 2009 |
| Priority date | — |
| Expiry date | Apr 22, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/005
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for measuring work function includes the steps of: (a) providing a field emission electron source having a carbon nanotube tip as a cathode electrode and a spaced anode electrode, having a predetermined spaced distance therebetween; (b) applying a voltage between the cathode electrode and the anode electrode and measuring a first current-voltage curve of the field emission electron source in a vacuum environment; (c) forming a layer of field emission material at least on the surface of the carbon nanotube tip; (d) measuring a second current-voltage curve of the now-treated field emission electron source in the same conditions as that in the step (b); (e) achieving two Fowler-Nordheim curves calculated from the two current-voltage curves according to the Fowler-Nordheim equation; and (f) comparing the two Fowler-Nordheim curves and calculating the work function of the field emission material therefrom.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.