Open AccessPhotocurrent response of carbon nanotube–metal heterojunctions in the terahertz range
Author(s) -
Yingxin Wang,
Guowei Zhang,
Liyan Qiao,
Jin Wei,
JiaLin Zhu,
Zhiqiang Chen,
Ziran Zhao,
JiaLin Sun
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.005895
Subject(s) - terahertz radiation , photocurrent , materials science , optoelectronics , heterojunction , photoconductivity , terahertz spectroscopy and technology , carbon nanotube , photomixing , terahertz time domain spectroscopy , photodetector , optics , nanotechnology , far infrared laser , physics , laser , terahertz metamaterials
We investigate the optoelectronic properties of a carbon nanotube (CNT)-metal heterostructure in the terahertz range. On the basis of terahertz time-domain spectroscopy characterization of a double-walled CNT (DWNT) film, we present and analyze the photocurrent measurement for a DWNT-nickel heterojunction illuminated by continuous-wave terahertz radiation. A significant current across the junction directly induced by terahertz excitation is observed and a negative photoconductivity behavior is found to occur in the device. The photocurrent shows a linear response to the bias voltage and the illumination power within the examined range. These phenomena support the feasibility of using CNT-metal heterojunctions as novel terahertz detectors.