Diamond/sp2-bonded carbon structures:: quantum well field electron emission?

Properties of the field electron emission for different diamond/sp(2)-bonded carbon nanostructures including chemical vapor deposition (CVD) diamond films and diamond/pyrocarbon composites are considered with respect to their structure. It is noted that the samples showing the emission at low threshold fields of 1-3 V/mum with satisfactory spatial uniformity typically contain a lot of sp(2)-bonded carbon phase, while samples which have a predominant diamond phase emit poorly. Studying the microscopic properties of the emission centers with special STM device ii was round, thar the emission is associated just with diamond/sp(2)-bonded carbon interfaces and thin conducting layers. Possible mechanisms of the emission including local field enhancement and reducing of the tunneling barrier due to NEA are analyzed. It is proposed to describe the emission from the samples using quantum well effects at thin carbon nanolayers and insulator/graphite interfaces. The mechanism does not suggest taking into account specific diamond properties, and it could be suitable for wide range of objects. (C) 2001 Elsevier Science B,V. All rights reserved.