Nanorobot assembly of carbon nanotubes for mid-IR sensor

Abstract

Carbon nanotubes (CNTs) have a potential to be efficient infrared (IR) detection material due to their unique electronic properties. As a one-dimensional nano-structural material, the ballistic electronic transport property makes the noise equivalent temperature difference smaller compared with other semi-conducting materials. In order to verify this unique property, a single pixel CNT-based infrared photodetector is fabricated by depositing the CNTs on the substrate surface and then aligning them to bridge the electrode gap using the atomic force microscopy (AFM)-based nano-robotic system. The photon-generated electron-hole pairs within the carbon nanotube are separated by an external electric field between the two electrodes. The separated carriers contribute to the current flowing through the carbon nanotube and form the photocurrent. By monitoring the photocurrent, the incident infrared can be detected and quantified. Experimental results show the good sensitivity of CNTs to the infrared light.