Structural and electronic properties of highly photoconductive amorphous carbon nitride

We have studied highly photoconductive amorphous carbon nitride (a-CNx) films prepared by RF-reactive magnetron sputtering. a-CNx is attractive as a potentially high performance photoconductive semiconductor suited to apply for such as an electron photography, ultraviolet (UV) detector and electron emitter, etc. In this paper, it is reported about the effects of high magnetic field on the sputtering process of a-CNx films. The experimental results show that films prepared in the higher magnetic field made by samarium cobalt magnets have less C = N triple bonding states, less electron spin density N-s = 10(18) cm(-3) and smoother surface morphology than that made by the usual magnetron sputtering using ferrite magnets. From these results, high magnetic field is effective to prepare hard and stable a-CNx films. We will also report a model of electronic density of states of a-CNx especially stressed on the Urbach energy region. A preliminary experiment on electroluminescence is also reported. (C) 1999 Elsevier Science S.A. All rights reserved.