Infrared detector based on single-walled carbon nanotube networks

In this work we presented the fabrication and characterization of infrared (IR) detectors based on low density single-walled carbon nanotube (SWNT) networks. The SWNTs were grown by thermal CVD. The interdigitated Al electrodes were deposited on the SWNT networks synthesized on the SiO₂(500 nm)/Si substrate and the SWNT networks were released by etching SiO₂ under the SWNTs. The fabrication procedure, which involves only common photolithography and metal deposition technologies, is simple and scalable for the manufacture of detectors. The low density of SWNTs decreases the intertube coupling during IR detecting. The electrical and IR sensitive properties of the detector were investigated. Results showed that the SWNT networks contact well with the electrodes and the detector shows rapid and remarkable responses to the changes of ON-OFF states of IR lamp and the IR radiations with different frequencies. The response time of detector to the changes of ON-OFF state of IR lamp is about 60 ms. The resistance response of the detector to high-frequency IR radiation at the frequency of 30 Hz can be distinctly observed.