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

摘要

We present a near-infrared photoresponse study of single-walled carbonnanotube/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 [(light current - darkcurrent)/dark current] is much larger in the SWCNT/polymer composite films. Thephotoresponse is up to 157% when SWCNTs are embedded in P3HT-b-PS while for apure SWCNT film it is only 40%. We also show that the photocurrent stronglydepends on the position of the laser spot with maximum photocurrent occurringat the metal-film interface. We explain the photoresponse due to excitondissociations and charge carrier separation caused by a Schottky barrier at themetallic electrode - SWCNT interface