Oxidation improvement of field electron emission from diamond nanomaterials

Porous diamond/sp2‐bonded carbon nanocomposites were studied to determine how their field electron emission properties and electrical conductivity depend on composition and post‐growth treatment. It was found that a treatment enriching the nanocomposites with oxygen could significantly improve the field emission from the diamond samples. The oxidized composites exhibited lower emission threshold fields (Eth = 1–2 V µm−1 compared with Eth = 4–6 V µm−1 for non‐oxidized samples) and improved emission uniformity (the number of emission sites per unit area). The composites with low sp2‐bonded carbon content, i.e. the more porous samples, typically show better results. The structure of the samples was studied using a C KVV Auger spectrometer, with x‐ray excitation of Auger emission. Possible reasons for the emission improvement by oxidation in this two‐phase carbon system are discussed. Copyright © 2004 John Wiley & Sons, Ltd.