TY - JOUR
T1 - Humidity sensitivity of carbon nanotube and poly (Dimethyldiallylammonium Chloride) composite films
AU - Liu, Litao
AU - Ye, Xiongying
AU - Wu, Kang
AU - Zhou, Zhaoying
AU - Lee, Dongjin
AU - Cui, Tianhong
PY - 2009/12/1
Y1 - 2009/12/1
N2 - This paper demonstrates a highly sensitive humidity sensor based on carbon nanotube and poly (dimethyldiallylammonium chloride) composite films. The composite film is deposited between interdigitated electrodes on a Si/SiO 2 substrate through layer-by-layer self-assembly technique. The resistance stability of the composite film is effectively improved through thermal annealing, and I-V characteristic of the film exhibits a very good linear behavior. The resistance increases exponentially with relative humidity from 20% to 98%, and a much higher sensitivity in comparison with pure carbon nanotube networks is achieved. With temperature increased, the water vapor density versus RH shifts upwards, while the resistance is reduced downwards. The resistance is dependent on temperatures with a negative coefficient. The composite films with multiwalled carbon nanotubes show an adjacent sensitivity, compared with the single-walled carbon nanotube composite films. The experimental results show that the humidity sensors have a fast response and a short recovery time, and their response is reversible. A simple model is proposed to explain the change of composite film resistance with humidity. The carbon nanotubes junctions may play a more important role in the overall resistance change for water molecule absorption.
AB - This paper demonstrates a highly sensitive humidity sensor based on carbon nanotube and poly (dimethyldiallylammonium chloride) composite films. The composite film is deposited between interdigitated electrodes on a Si/SiO 2 substrate through layer-by-layer self-assembly technique. The resistance stability of the composite film is effectively improved through thermal annealing, and I-V characteristic of the film exhibits a very good linear behavior. The resistance increases exponentially with relative humidity from 20% to 98%, and a much higher sensitivity in comparison with pure carbon nanotube networks is achieved. With temperature increased, the water vapor density versus RH shifts upwards, while the resistance is reduced downwards. The resistance is dependent on temperatures with a negative coefficient. The composite films with multiwalled carbon nanotubes show an adjacent sensitivity, compared with the single-walled carbon nanotube composite films. The experimental results show that the humidity sensors have a fast response and a short recovery time, and their response is reversible. A simple model is proposed to explain the change of composite film resistance with humidity. The carbon nanotubes junctions may play a more important role in the overall resistance change for water molecule absorption.
KW - Carbon nanotube (CNT)
KW - Composite film
KW - Humidity sensitivity
KW - Layer-by-layer (LbL) self-assembly
KW - Poly (dimethyldiallylammonium chloride)
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U2 - 10.1109/JSEN.2009.2030381
DO - 10.1109/JSEN.2009.2030381
M3 - Article
AN - SCOPUS:78349261503
VL - 9
SP - 1308
EP - 1314
JO - IEEE Sensors Journal
JF - IEEE Sensors Journal
SN - 1530-437X
IS - 10
ER -