Field emmitters of wide-bandgap materials
US5990604A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 2, 1998 |
| Grant date | Nov 23, 1999 |
| Priority date | — |
| Expiry date | Feb 2, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2201/30457
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Improved field-emission devices are based on composing the back contact to the emitter material such that electron-injection efficiency into the emitter material is enhanced. Alteration of the emitter material structure near the contact or geometric field enhancement due to contact morphology gives rise to the improved injection efficiency. The devices are able to emit electrons at high current density and lower applied potential differences and temperatures than previously achieved. Wide-bandgap emitter materials without shallow donors benefit from this approach. The emission characteristics of diamond substitutionally doped with nitrogen, having a favorable emitter/vacuum band structure but being limited by the efficiency of electron injection into it, show especial improvement in the context of the invention. The injection-enhancing contacts can be created by combining the emitter material with an appropriate metal compound and annealing or by conventional dry anisotropic etching or ion bombardment techniques.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.