Carbon nanotube mat as substrate for ZnO nanotip field emitters

We have reported the synthesis of ZnO nanotips on a multi walled carbon nanotube (MWCNT) mat by a vapour transport process. This combination of ZnO nanotips and a MWCNT mat exhibit ideal field emission behaviour. The turn on field and threshold field is found to be 0.34 and 1.5 V mu m(-1), respectively. The low threshold field is due to the good adherence of the ZnO nanotips on the MWCNT mat. The field enhancement factor is found to be 5 x 10(2) which is in agreement with the intrinsic field emission factor of ZnO nanotips. The emission current is found to be highly stable even at moderate vacuum.