TY - GEN
T1 - Improving the detectability of CNT based infrared sensors using multi-gate field effect transistor
AU - Chen, Hongzhi
AU - Xi, Ning
AU - Lai, King W.C.
AU - Fung, Carmen K.M.
AU - Yang, Ruiguo
PY - 2010
Y1 - 2010
N2 - Carbon nanotube (CNT) is a novel one dimensional (1D) material that has unique electrical and optoelectronic properties. Photo-sensors using CNT can sense infrared signals by using Schottky barriers between metal and nanotube, which are able to separate photo-generated electron-hole pairs in order to generate photocurrent or photovoltage for detection and quantification. It has been demonstrated that both asymmetric metal structure and electrical field can improve the performance of the sensors by manipulating the energy alignment between metal and CNT. However, it is not clear how to optimize the design of the CNT photo-sensors. An asymmetric multi-gate field effect transistor based infrared detector was fabricated, integrating with asymmetric metal structure (Au-CNT-Al) and multiple gates, which allow for controlling the doping level at source, drain and channel independently. It was found that dark current was suppressed and photocurrent was enhanced by applying negative gate voltages, thus improving sensor's performance. The CNT detector exhibited similar photo-response when modulating the doping level of CNT segments at source, drain and bulk. We ascribe this to the charge distribution that has a long tail extending over the whole tube.
AB - Carbon nanotube (CNT) is a novel one dimensional (1D) material that has unique electrical and optoelectronic properties. Photo-sensors using CNT can sense infrared signals by using Schottky barriers between metal and nanotube, which are able to separate photo-generated electron-hole pairs in order to generate photocurrent or photovoltage for detection and quantification. It has been demonstrated that both asymmetric metal structure and electrical field can improve the performance of the sensors by manipulating the energy alignment between metal and CNT. However, it is not clear how to optimize the design of the CNT photo-sensors. An asymmetric multi-gate field effect transistor based infrared detector was fabricated, integrating with asymmetric metal structure (Au-CNT-Al) and multiple gates, which allow for controlling the doping level at source, drain and channel independently. It was found that dark current was suppressed and photocurrent was enhanced by applying negative gate voltages, thus improving sensor's performance. The CNT detector exhibited similar photo-response when modulating the doping level of CNT segments at source, drain and bulk. We ascribe this to the charge distribution that has a long tail extending over the whole tube.
KW - Carbon nanotube
KW - Field-effect transistor
KW - Infrared detector
KW - Optoelectronics
UR - http://www.scopus.com/inward/record.url?scp=79951838503&partnerID=8YFLogxK
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U2 - 10.1109/NANO.2010.5697813
DO - 10.1109/NANO.2010.5697813
M3 - Conference contribution
AN - SCOPUS:79951838503
SN - 9781424470334
T3 - 2010 10th IEEE Conference on Nanotechnology, NANO 2010
SP - 727
EP - 731
BT - 2010 10th IEEE Conference on Nanotechnology, NANO 2010
T2 - 2010 10th IEEE Conference on Nanotechnology, NANO 2010
Y2 - 17 August 2010 through 20 August 2010
ER -