| Autor: |
Wong, W. K., Meng, F. Y., Li, Q., Au, F. C. K., Bello, I., Lee, S. T. |
| Předmět: |
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| Zdroj: |
Applied Physics Letters; 2/4/2002, Vol. 80 Issue 5, p877, 3p, 1 Diagram, 3 Graphs |
| Abstrakt: |
Field emission from multihead silicon (Si) cones was substantially improved by cesium (Cs) coating. Increasing the Cs coating lowered the emission turn-on field (for 10 μA/cm[sup 2]) from 25 V/μm to a saturated value of 13 V/μm, while the threshold field (for 10 mA/cm[sup 2]) decreased by 30%, dropping from 27 V/μm for Si cones coated with 1.8 monolayers (ML) of Cs to a saturated value of 19 V/μm with 4.1 ML of Cs. The Cs-treated Si cones could give an emission current density that was three to ten times that delivered by bare Si cones. The work function reduced by a factor of 1.43 for Si cones coated with 4.9 ML of Cs with reference to the untreated Si cones. From the slope of Fowler–Nordheim plot, the field enhancement factor β was found to increase by a factor of 2.02 for Si cones coated with 2.5 ML of Cs and then reduce to 1.57 after the 4.9 ML of Cs deposition. Reduction of the factor β might occur because of a thick Cs layer, which could flatten the sharp cone features. Stability test showed that no current decay was observed at a current density of 0.8 mA/cm[sup 2] under a constant applied field of 16 V/μm during the 10 h investigation. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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