Enhanced low-temperature thermionic field emission from surface-treated N-doped diamond films

• Published in: Diamond and related materials 2002-03, Vol.11 (3-6), p.774-779
• Main Authors: Köck, F.A.M., Garguilo, J.M., Brown, Billyde, Nemanich, R.J.
• Format: Article
• Language: English
• Subjects: Chemical vapor deposition (CVD); Condensed matter: electronic structure, electrical, magnetic, and optical properties; Diamond; Electron and ion emission by liquids and solids; impact phenomena; Exact sciences and technology; Field emission; Field emission, ionization, evaporation, and desorption; Physics; Thermionic emission
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/S0925-9635(02)00006-7

Nitrogen-doped diamond films have been synthesized for application as a low-temperature thermionic field-emission cathode. The critical result of this study is the observation of uniform electron emission from UV photo-excitation and from thermionic field emission for films terminated with hydrogen or a 0.3-nm Ti layer. The samples were imaged with photoelectron emission microscopy (PEEM) and thermionic field-emission electron microscopy (T-FEEM) at temperatures up to 900 °C, and the electron emission current was recorded vs. the applied voltage. Hydrogen-passivated films show enhanced electron emission, but become unstable at elevated temperatures, while Ti-terminated films showed similar enhanced emission at temperatures up to 950 °C. Temperature-dependent I/V measurements show strongly increased electron emission at higher temperatures, suggesting that electron emission originates from the conduction band. These results indicate a promising new material for the production of low-temperature, high-brightness electron sources.