Similarity in field electron emission from nanocrystalline diamond and related materials

Results on a complex study of macroscopic and microscopic electronic proper ties of nanocrystalline diamond and related material (BN, GaN, CN) films ar e presented. It was found that all the samples studied showed similar depen dencies of macroscopic emission parameters (the Fowler-Nordheim work functi on, the effective emitting area) on the film emissivity. Also, some microsc opic properties were found to be common for all the films tested. It was ge nerally observed that field electron emission occurred at nanosized regions on the boundary of high and low resistivity areas, and peaks of the emissi on intensity were associated with a lowered surface electron potential. Bas ed on the experimental data, a mechanism of field electron emission from th e surface of nanocrystalline films is proposed. We suppose that electrons a re transported from narrow conducting channels into vacuum through specific low-dimensional regions, the electronic properties of which, due to the qu antum size effect, are different from the bulk material. In this case the b ase material grains play a role of the conductive channel-containing matrix as well as a heat sink. Details of the new low-field emission mechanism in cluding the filling of discrete energy states, and the decrease in the work function under the action of electric field are discussed. (C) 2001 Elsevi er Science B.V. All rights reserved.