Field-Induced Insulator to Semimetal Transition and Field Electron   Emission of Nanorods of Semiconductors of Wide Energy Band Gaps
  Significant field emission is found theoretically possible from nanorods of semiconductors of wide energy band gaps. If the nanorod has a thin surface layer containing a large number of localized states, a part of nanorod can exhibit an insulator-to-semimetal transition under high enough fields of direction parallel to its axis, so that field emission occurs at the apex of the metal like tip. The field emission property of silicon carbide nanorods is studied as an example and found to be in qualitative agreement with the experimental findings. 
Zhibing Li, Weiliang Wang, Shaozhi Deng, Ningsheng Xu, Guiyang Huang