Highly Flexible and Transparent Single Wall Carbon Nanotube Network Gas Sensors Fabricated on PDMS Substrates
- PDF / 626,797 Bytes
- 7 Pages / 612 x 792 pts (letter) Page_size
- 80 Downloads / 201 Views
0922-U11-10
Highly Flexible and Transparent Single Wall Carbon Nanotube Network Gas Sensors Fabricated on PDMS Substrates Chi-Won Cho1, Chae-Hyun Lim2, Chang-Seung Woo2, Hyung-Suk Jeon2, Bonghyun Park2, Heongkyu Ju2, Cheol-Jin Lee3, Sunglyul Maeng4, Ki-Chul Kim4, Sang Hyeob Kim4, and SeungBeck Lee1,2 1 Electronics and Computer Engineering, Hanyang University, 17 Haengdangdong, Seongdonggu, Seoul, 133-791, Korea, Republic of 2 Nanotechnology, Hanyang University, 17 Haengdangdong, Seongdonggu, Seoul, 133-791, Korea, Republic of 3 Electronics and Computer Engineering, Korea University, 5-1 Anamdong, Seongbukgu, Seoul, 136-701, Korea, Republic of 4 Cambridge-ETRI Joint R&D Centre, Electronics and Telecommunications Research Institute, Daejeon, 305-350, Korea, Republic of
ABSTRACT We report on the basic characteristics and gas sensing operation of density controlled single-walled carbon nanotube (SWCNT) thin films on poly(dimethyl siloxane) (PDMS) substrates. The vacuum filteration and PDMS mold transfer method allowed the density of SWCNT distributed to have non-local uniformity. The optical transparency of the SWCNT thin films was inversely proportional to SWCNT density and conductivity. The flexible SWCNT thin film showed high mechanical stability with negligible change in conductance after being bent by 180o. We evaluated its gas sensing operation depending on SWCNT density and bias voltage. It was shown that lower SWCNT density thin films had higher sensitivity to NH3 gas, which may be due to higher exposed surface area for lower density SWCNT thin films. Also, we found that lower bias voltage devices showed faster recovery times. The results show that vacuum filteration and mold transfer method produced flexible SWCNT thin films that have stable mechanical and electrical characteristics and also stable gas sensing capabilities making them applicable to future flexible integrated sensors.
INTRODUCTION Single wall carbon nanotubes (SWCNTs) have been considered as one of the key candidate materials for future electronic device application, due to many outstanding characteristics such as high mechanical strength, chemical stability, high electrical conductivity and high thermal conductivity [1]. Especially, their high surface to volume ratio and one dimensional transport nature allows them to be highly sensitive to changes in the surface potential states, which makes them ideal for highly sensitive chemical sensor application [2]. However, for industrial application of SWCNTs to high sensitivity sensors a few fundamental and technical obstacles must be overcome. As synthesized, about 2/3 of SWCNTs are semiconductors while the rest are metallic [3]. Also, metallic contacts to SWCNTs results in
Figure 1. Vacuum filteration and PDMS mold transfer fabrication of flexible SWCNT network thin film. Schematic illustration of (a) the vacuum filteration method using 30 nm average pore size AAO filter membrane and (b) PDMS mold transfer of SWCNT network. (c) Optical image of the resulting flexible SWCNT network thin film. Sc
Data Loading...
