Energy distribution of thermally emitted negative particles from type Ia diamond (100)

• Published in: Diamond and related materials Vol. 10; no. 3; pp. 496 - 499
• Main Authors: Goeden, C., Dollinger, G.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-03-2001; Elsevier
• Subjects: Absorption; Earth sciences; Earth, ocean, space; Exact sciences and technology; Hydrogen; Mineralogy; Negative electron affinity; Non silicates; Thermal emission; Thermal emission; Absorption; Negative electron affinity; Hydrogen; adsorption; diamond; absorption; nitrogen; ions; hydrogen; desorption; electrons; high temperature; native elements; thermal emission; energy
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/S0925-9635(00)00454-4

This study explores the electron emission of natural, nitrogen-doped diamond at elevated temperatures. The diamond was resistively heated up to 870°C. Accruing negatively charged particles where accelerated by a bias voltage of 30 V and the energy distribution is measured. The electrons are analysed by an electrostatic deflection resulting in an energy resolution of 70 meV. A hydrogen-free surface at a base pressure of 2.0×10
−9 mbar shows a very small emission. The energy distribution has its maximum at 2.5 eV and a FWHM of 0.52 eV. Beside the main emission peak, some smaller features are observable at higher energies. An atomic hydrogen supply at 1.9×10
−5 mbar increases the emission by a factor of 30. With some delay to the hydrogen supply, a new low energy peak appears. The increase in intensity during hydrogen adsorption is explained by the occurrence of a negative electron affinity (NEA) of the hydrogen-covered diamond surface. The low-energy feature might be due to hydrogen ions, either desorbing from the surface or from charge transfer during collisions of gas phase hydrogen with the diamond surface.