Significant emission current enhancement has been achieved for surface conduction electron emitter, due to the special three-dimensional nanocrack structure fabricated by the thermal shock process. The three-dimensional configuration strongly changed the electric field distribution and controlled the emission electron trajectory. Thermal shock treatment was also used to increase the edge roughness of the nanocrack and thereby dramatically improved the field emission characteristics. Stable and uniform electron emission was observed with turn-on voltage of 150 V. The surface conduction current of 400 mu A for 6 cells was obtained with the detector voltage of 1 kV and the gap voltage of 170 V. (C) 2011 Elsevier B.V. All rights reserved.