METALLIC CARBON NANOTUBES, MICROWAVE CHARACTERIZATION AND DEVELOPMENT OF A TERAHERTZ DETECTOR

by Fu, Kan

It is reported that terahertz radiation from 0.69 to 2.54 THz has been sensitively detected in a device consisting of bundles of carbon nanotubes containing single wall metallic carbon nanotubes, quasi-optically coupled through a lithographically fabricated antenna, and a silicon lens. The measured data are consistent with a bolometric detection process in the metallic tubes and the devices show promise for operation well above 4.2 K. Microwave measurements have also been done up to 20GHz. Voltage responsivity got here is comparable to that of the Schottky diode detector. The detection at microwave frequencies are consistent with the diode detection mode. S11 parameters of different devices were measured using microwave probing, and de-embedding process has been done to get the impedances of the SWNTs. A circuit model was fitted based on the measurement data, and different values of the elements of the circuit are extracted. Frequency response from the circuit model is consistent with the experimental data.