Modification on the band structure and the related emission characteristics of defective diamond films doped with boron

Electron field emission properties of multilayer diamond films containing an undoped diamond layer grown on top of boron-doped diamond layer are observed to be significantly superior to that of the single layer diamond films, boron-doped or undoped. The electron emission capacity Je.of the multilayer diamonds increases as the thickness of the undoped layer reduces, with the turn-on field E0.and effective work function we.essentially unchanged. This phenomenon is accounted for by the bending of the electronic band structure, such that the electrons in the acceptor levels of the underlying boron-doped layer can jump across the junction to the impurity bands in the top undoped layer, and then readily field emitted. The optimum electron emission properties obtained are: Jes4890 mArcm2 at 35 Vrmm., E0s26 Vrmm and wes0.28 eV. q1999 Published by Elsevier Science B.V. All rights reserved.