Thermally stimulated exoelectronic emission of CVD diamond films

Exoemissive properties of several CVD diamond films (undoped or doped with nitrogen) are studied by the thermally stimulated exoelectronic emission (T SEE) method. Some experimental results are obtained after UV or X-ray irrad iation. After UV irradiation, a single TSEE peak is observed at 605 or 625 K, depending upon the growth parameters. The existence of the exoemission s ignal is related to the surface morphology: facetted surfaces give rise to exoelectronic emission, more especially in the presence of both 111 and 100 faces, while smooth surfaces do not or only to a limit extent. A possible indication of negative electron affinity is observed at about 273 K. (C) 20 00 Elsevier Science S.A. All rights reserved.