Title :
Photocarrier Relaxation Behavior of a Single ZnO Nanowire UV Photodetector: Effect of Surface Band Bending
Author :
Chen, Ming-Wei ; Retamal, Jose Ramon Duran ; Chen, Cheng-Ying ; He, Jr-Hau
Author_Institution :
Dept. of Electr. Eng., Nat. Taiwan Univ., Taipei, Taiwan
fDate :
3/1/2012 12:00:00 AM
Abstract :
The surface effect on the photocarrier relaxation behavior using a single ZnO nanowire (NW) ultraviolet (UV) photodetector has been evaluated. The pronounced surface effect leads to the enhancement-mode field-effect-transistor behavior in dark and accounts for the slow relaxation behavior after switching off the illumination. The recovery of photocurrent is found to be strongly related to the intensity of UV light and the diameter of NWs, indicating that the photocarrier relaxation behavior is dominated by surface band bending (SBB). A model for the relaxation behavior based on the SBB of NWs is proposed to interpret the experimental results.
Keywords :
II-VI semiconductors; field effect transistors; nanowires; photoconductivity; photodetectors; relaxation; semiconductor quantum wires; ultraviolet detectors; wide band gap semiconductors; UV light intensity; ZnO; enhancement-mode field effect transistor; photocarrier relaxation behavior; photocurrent recovery; single zinc oxide nanowire UV photodetector; surface band bending effect; Lighting; Logic gates; Photoconductivity; Photodetectors; Scanning electron microscopy; Switches; Zinc oxide; Nanowire (NW); ZnO; photodetector; relaxation time; surface band bending (SBB);
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2011.2180012
