Advanced nanodiamond emitter with pyramidal tip-on-pole structure for emission self-regulation Available to Purchase

In this paper, we report an innovative nanodiamond field emitter structure consisting of an individual pyramidal tip sitting on top of a ballast resistor “pole.” The tip-on-pole nanodiamond structures are fabricated by a new mold transfer process that is comprised of reactive-ion-etching of 3.5 μm-thick thermal oxide on Si substrate, anisotropic etching of Si, tip sharpening by thermal oxidation and chemical vapor deposition of nanodiamond. The fabricated tip-on-pole nitrogen-incorporated nanodiamond emitter exhibits a low turn-on electric field of 3.5 V/um and a very high emission current density of ∼1.7 A/cm² at an electric field of ∼7.5 V/um. Analysis of the emission current based on Fowler–Nordheim theory indicates a current regulated regime due to the pole-structured ballast resistor with the resistance value of ∼140 kΩ. Thus, the diamond pole ballast resistor has proven to provide self-limiting of emission current that improves the total current density as well as the emission current stability of the pyramidal nanodiamond emitters. Therefore, the proposed tip-on-pole nanodiamond emitters show great promise for high current and power applications.