Diamond/sp(2)-bonded carbon structures: quantum well field electron emission?

Properties of the field electron emission for different diamond/sp(2)-bonde d carbon nanostructures including chemical vapor deposition (CVD) diamond f ilms and diamond/pyrocarbon composites are considered with respect to their structure. It is noted that the samples showing the emission at low thresh old fields of 1-3 V/mum with satisfactory spatial uniformity typically cont ain a lot of sp(2)-bonded carbon phase, while samples which have a predomin ant diamond phase emit poorly. Studying the microscopic properties of the e mission centers with special STM device ii was round, thar the emission is associated just with diamond/sp(2)-bonded carbon interfaces and thin conduc ting layers. Possible mechanisms of the emission including local field enha ncement and reducing of the tunneling barrier due to NEA are analyzed. It i s proposed to describe the emission from the samples using quantum well eff ects at thin carbon nanolayers and insulator/graphite interfaces. The mecha nism 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.