Grain boundary field electron emission from CVD diamond films

• Published in: Diamond and related materials Vol. 8; no. 2; pp. 763 - 767
• Main Authors: Karabutov, A.V, Frolov, V.D, Pimenov, S.M, Konov, V.I
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-03-1999
• Subjects: Diamond films; Fowler–Nordheim injection; Morphology; Scanning tunneling microscopy; Scanning tunneling microscopy; Fowler–Nordheim injection; Morphology; Diamond films
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/S0925-9635(98)00308-2

Results are reported on microscopic study of electronic and structural properties of field emission centers for chemical vapor deposition diamond films. The field electron emission (FEE) for the best films studied was observed at >3
V
μm
−1, and ultralow (<0.1
eV) values of effective work function derived from Fowler–Nordheim plot fitting are discussed. A specially designed high vacuum scanning tunneling-field emission microscope was applied for simultaneous mapping of FEE intensity, morphology, work function and local electroconductivity evaluation. It was found that the emission centers were not associated with sharp morphology protrusions. On the contrary, they correspond to morphology pits (grain boundaries) which also show a low value of the work function. A mechanism of the low-FEE near grain boundaries including field enhancement of narrow conductive channels between insulating diamond grains is discussed.