Effects of Chemical Surface Treatments on Field Emission of Diamond Film

摘要

Field emission of diamond film was enhanced aftersurface treatments using boiling HCl and aqua regia solutions.The current generated by the emission of electron was increasedand the threshold field was reduced from 18.1 to 13.8 V/#mu# mby the surface treatment. The surface roughness was increased by24.4 percent with aqua regia treatment, but the calculatedcurrent-voltage curves were not consistent with the measured ones.It was found that the binding energies of C-C and C-O bonds wereincreased after the aqua regia treatment and the Fermi level ofthe aqua-rigia-treated surface was increased by 2.2 eV. Thisprovides evidence that the enhancement of electron emissionoriginated from the reduction of work function, caused by thechemisorption of oxygen atoms. The effective electron affinitychanged to negative, leading to the reduction of the potentialbarrier height and width for electron emission at the surface of diamond.