Ultrahigh photocurrent gain in m -axial GaN nanowires
Journal
Applied Physics Letters
Journal Volume
91
Journal Issue
22
Pages
223106-1 - 223106-3
Date Issued
2007
Author(s)
Abstract
An ultrahigh photocurrent gain has been found in the ultraviolet-absorbed GaN nanowires with m -directional long axis grown by chemical vapor deposition. The quantitative results have shown the gain values at 5.0× 104 -1.9× 105 of the GaN nanowires with diameters from 40 to 135 nm are near three orders of magnitude higher than the values of 5.2× 101 -1.6× 102 estimated from the thin film counterparts. The intensity-dependent gain study has shown that the gain value is very sensitive to the excitation intensity following an inverse power law and no gain saturation observed in this investigated intensity range from 0.75 to 250 W m2. This behavior has strongly suggested a surface-dominant rather than trap-dominant high gain mechanism in this one-dimensional nanostructure. The strong carrier localization effect induced by the surface electric field in the GaN nanowires is also discussed. © 2007 American Institute of Physics.
Other Subjects
Carrier lifetime; Chemical vapor deposition; Electric excitation; Electric fields; Nanowires; Photocurrents; Excitation intensity; Gain value; Ultrahigh photocurrent gain; Gallium nitride
Publisher
American Institute of Physics
Type
journal article