Title :
Field Emission of ZnO Nanowires in Low Vacuum Following Various Enhancements Made by Exposure to UV
Author :
Hsu, Cheng-Liang ; Tsai, Yao-Ching
Author_Institution :
Dept. of Electr. Eng., Nat. Univ. of Tainan, Tainan, Taiwan
Abstract :
High-density vertical ZnO nanowires (NWs) were synthesized by vapor phase transport deposition without a metal catalyst or template. The work function φ of ZnO NWs was reduced to 3.7 eV by exposure to UV. At a low vacuum of 10-3 Torr, the UV light improved the field emission performance and reduced the turn-on voltage such that they were better than those of normal field emission in a high vacuum. The depletion layer of NWs disappeared because surface O2- oxygen molecules were removed by exposure to UV light. The enhancement by UV remained even after the UV light had been turned off for 20 min.
Keywords :
II-VI semiconductors; field emission; nanofabrication; nanowires; semiconductor growth; vapour deposition; wide band gap semiconductors; work function; zinc compounds; UV light; ZnO; field emission performance; high-density vertical ZnO nanowires; nanowire depletion layer; pressure 0.010 torr; surface oxygen molecules; time 20 min; turn-on voltage; vapor phase transport deposition; work function; Current measurement; Morphology; Nanowires; Substrates; Temperature measurement; Voltage measurement; Zinc oxide; Enhance; ZnO nanowires (NWs); field emission (FE); low vacuum; ultraviolet (UV);
Journal_Title :
Nanotechnology, IEEE Transactions on
DOI :
10.1109/TNANO.2012.2212913
