Abstract
A new model is presented to resolve the Nottingham-Fleming and Henderson controversy concerning the average energy of the replacement electrons in field emission. In addition to thermal excitation, we introduce the tunnelling-state contribution as a mechanism to vacate levels available for replacement electrons. It is found that the condition for a steady-state current is not satisfied without the tunnelling-state contribution. The present result of the net energy exchange Δε{lunate} per electron obtained as a function of both temperature and field shows much improved agreement with experimental data. The inversion temperature Ti as a function of field is now in good quantitative agreement with existing experimental data. Contrary to the assertion of Nottingham [Phys. Rev. 59 (1941) 907] that the replacement energy is equal to the chemical potential of the emitter, our results favor the argument of Fleming and Henderson [Phys. Rev. 58 (1940) 887] that the replacement process takes place in the available energy states below the Fermi energy in the emitter. Non-equilibrium effects in the emitter due to fields and temperature gradients evaluated within the relaxation time approximation are noticeable only for large fields.
Original language | English (US) |
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Pages (from-to) | 1-6 |
Number of pages | 6 |
Journal | Applied Surface Science |
Volume | 76-77 |
Issue number | C |
DOIs | |
State | Published - Mar 2 1994 |
All Science Journal Classification (ASJC) codes
- General Chemistry
- Condensed Matter Physics
- General Physics and Astronomy
- Surfaces and Interfaces
- Surfaces, Coatings and Films