Molecule-modulated photoconductivity and gain-amplified selective gas sensing in polar GaN nanowires
Journal
Applied Physics Letters
Journal Volume
95
Journal Issue
23
Pages
233119-1 - 233119-3
Date Issued
2009
Author(s)
Abstract
We report the strong molecular effects on the surface-dominant photoconductivity with high-gain transport in the polar GaN nanowires. Both the transient and steady-state photocurrents are sensitive and selective to the adsorptions of oxygen and hydrogen. The surface band bending of GaN nanowires is proposed to be effectively reduced or enhanced by oxygen or hydrogen, respectively, as a donorlike or acceptorlike surface state. The molecular effect, corroborated with the high-gain photoresponse nature of GaN nanowires is found to amplify the molecule-selective photocurrent signal by near three orders of magnitude higher than its counterpart in dark current. The molecule-tunable photoconductivity, as demonstrated here, would benefit a variety of applications, ranging from the high-gain optoelectronic devices, photoelectric energy transducer, as well as gas and chemical sensors.
SDGs
Publisher
American Institute of Physics
Type
journal article