Parasitic capacitive coupling analysis of carbon nanotube based infrared detector

Infrared (IR) sensor has extended imaging from visible spectrum to millimeter wavelength, which has been widely used for military and civilian application. While the unusual carbon nanotube (CNT) based nanotechnology has been made much progress in research and industry, the unique properties of CNT lead to investigate of CNT based IR detectors. In this paper, CNTs-metal based Schottky barrier structure non cryogenic IR detector was designed to detect IR irradiance. The parasitic capacitance was analyzed when device size decreased. The experimental results show that the parasitic capacitance between electrodes deteriorates photocurrent response in CNT IR detector. Meanwhile, low dielectric constant polymer material polyimide was proposed in IR detector design, the experimental results have shown that, the polymer based interfacial layer has strong substrate noise reduction on CNT IR sensor. The dark current is less than 0.3 nA under the condition of photocurrent 100 nA, the noise at 0.5 nA when CNT-metal contact was fabricated on polyimide material.