Near-infrared photoresponse in single-walled carbon nanotube/polymer composite films

We present a near-infrared photoresponse study of single-walled carbon nanotube/poly(3-hexylthiophene)-block-polystyrene polymer (SWCNT/P3HT-b-PS) composite films for different loading ratios of SWCNT in the polymer matrix Compared to the pure SWCNT film, the photoresponse [flight current - dark current)/dark current) is much larger in the SWCNT/polymer composite films The photoresponse is up to 157% when SWCNTs are embedded in P3HT-b-PS while for a pure SWCNT film it is only 40% We also show that the photocurrent strongly depends on the position of the laser spot with maximum photocurrent occurring at the metal-film interface we explain the photoresponse due to exciton dissociations and charge carner separation caused by a Schottky barrier at the metallic electrode-SWCNT interface (C) 2009 Elsevier Ltd All rights reserved