Influence of the heterojunction on the field emission from tetrahedral amorphous carbon on Si

In order to study the influence of the back barrier on the electron emissio n properties of tetrahedral amorphous carbon (ta-C), we have deposited iden tical films on p and n+ Si. The valence and conduction band offsets were me asured for ta-C on p and n+ Si using in situ x-ray photoelectron spectrosco py and optical spectroscopy. From the band measurements it is shown that th ere is a substantial back barrier to emission. We show that for films havin g very similar properties, the electron emission can be influenced by the t a-C/Si heterojunction. (C) 2000 American Institute of Physics. [S0003-6951( 00)00138-8].