Correlating Thermionic Emission with Specific Surface Reconstructions in a Hydrogenated Single-Crystal Diamond

Area of Science:

• Materials Science
• Surface Science
• Condensed Matter Physics

Background:

• Thermionic emission is crucial for electron emission, dependent on material surface properties like low work function.
• The traditional Richardson-Dushman equation does not account for temperature-driven dynamic surface transformations.
• Understanding these dynamic processes is key to optimizing thermionic emitters.

Purpose of the Study:

• To develop a novel model for thermionic emission that incorporates dynamic surface changes.
• To correlate thermionic emission components with specific surface reconstruction phases.
• To investigate the impact of surface structure tailoring on electron emission.

Main Methods:

• Development of a new theoretical model for thermionic emission.
• Experimental validation using hydrogenated single-crystal and polycrystalline diamond emitters.
• Analysis of surface reconstruction phases and their effect on emission.

Main Results:

• The new model accurately reproduces the influence of dynamic surface changes on electron emission.
• Specific surface reconstruction phases were correlated with thermionic emission characteristics.
• Tailoring the C(100)-(2 × 1):H surface reconstruction increased diamond thermionic emission by orders of magnitude.

Conclusions:

• The proposed model enhances the understanding of thermionic emission by including dynamic surface effects.
• Optimizing surface structures, particularly C(100)-(2 × 1):H, offers a pathway to significantly improve thermionic emission.
• The findings are potentially applicable to a wide range of thermionic emitting materials.