Field Emission from One-Dimensional Submicron Diamond Rods

Abstract

One-dimensional boron-doped submicron diamond rods (SDRs) were fabricated on diamond/Si substrates by oxygen plasma etching. The SDRs are ∼4.5 µm in height and ∼383 nm in diameter. Iron oxide coated on SDRs is essential in the formation of one-dimensional SDRs. However, the as-etched SDRs suffer with high turn-on field (ETO) and low field emission current density (JFE) due to the iron oxide. A huge improvement in the field emission characteristics can be achieved by removing iron oxide using a wet-etch process in a diluted HCl (37%). After the wet-etch, the SDRs exhibit a low ETO value of4.5 V/µm (at 10 µA/cm2) and a high JFE value of 30 mA/cm2 (at 8.5 V/µm). The FE emitter is only stable for a short period of time at high current stress owing to the rounding of the tips of SDRs.