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

Volume

33

Issue

3

fYear

2012

fDate

3/1/2012 12:00:00 AM

Firstpage

411

Lastpage

413

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);

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2011.2180012

Filename

6144690