IR Photodetectors and Bolometers Based on Carbon Nanotubes


SEM image of single walled carbon nanotube (SWNT)- Si heterojunction.

A new generation of IR photodetectors and bolometers are in the focus of Emitech's activity. We were the first to report about photoconductive response of carbon nanotube film illuminated by white/NIR light (not laser pulse) of low intensity19a. The use of carbon nanotubes as an advanced nanomaterial for photodetectors is very attractive because of their suppressed thermal noise and the opportunity to tune the operational range by varying the nanotube diameter. Recently, we found that the junction between nanotubes and some semiconductors exhibits photoconductivity at far IR light 9a. This project was awarded by a Phase II SBIR grant in 2008 and was successfully completed in 2010. It is remarkable that the similar device can function as a novel type of the hybrid solar cell comprising carbon nanotube- Si heterojuction 10a, 11a, 12a, where the carbon nanotubes works as an active photosensing components.

Another example of  novel nanocomposite for bolometric applications is the  incorporation of aligned single walled carbon nanotubes in the polystyrene matrix. In 2012 we  demonstrated that such material exhibits an enhanced  responsivity (up to 500 V/W , the  highest responsivity  reported today among carbon nanotube bolometers) and a flat spectral response in  NIR and mid-IR spectral range 6a.