A polarized infrared thermal detector made from super-aligned multiwalled carbon nanotube films

Carbon nanotube (CNT) films, easily drawn from super-aligned CNT arrays with a large area and a good compatibility with semiconductor technology, have been used as light sensitive materials for infrared (IR) detection. A bolometric CNT detector made from one layer of super-aligned CNT film shows a 15.4% resistance change under 10 mW mm-2 of IR illumination and a fast characteristic response time of 4.4 ms due to its ultra-small heat capacity per unit area in vacuum at room temperature. Besides the power intensity detection, the anisotropic property of the super-aligned CNT films makes them ideal materials to detect the polarization of IR light simultaneously, which provides great potential in infrared imaging polarimetry. Theoretical analyses have been carried out to investigate the influences of CNT film properties on the responsivity and response time of the detector.