Efficient electron emitter utilizing boron-doped diamond tips with sp2 content

Abstract A practical technique to enhance the electron emission of diamond tips by incorporation of boron dopant and sp 2 content is reported. The effects of boron doping on electron field emission from an array of micro-patterned polycrystalline pyramidal diamond microtips with varying sp 2 content have been systematically studied. The field emission characteristics of undoped and boron-doped diamond tips are significantly improved by increasing sp 2 content of diamond tips. By increasing sp 2 content, the turn-on electric field can be reduced more than 50% for both undoped and boron-doped diamond tips. Likewise, the turn-on electric field of the diamond tips with higher sp 2 content decreases substantially with boron doping. A new field emission mechanism, that is, an increase in the field enhancement factor due to hole accumulation via the formation of cascaded sp 2 -diamond-sp 2 embedded microstructures in diamond tips, is a possible explanation for the enhanced effects of boron doping and sp 2 content on the diamond field emission characteristics.