Exploring the effects of optically generated dipoles on organic photodetector infrared detection

Abstract Sensing from the ultraviolet–visible to the infrared is bringing more attentions recently. Here, we report the effects of optically generated dipoles within PTB7 layer on photocurrent and photoresponse in single wall carbon nanotube-based photodetectors. The observations in this work provide the direct evidence that optically generated dipoles within the PTB7 layer can be aligned by a built-in field, and then consequently affect dissociation of photo-excited electron-hole pairs in single wall carbon nanotubes. Additionally, PL (photoluminescence) of single wall carbon nanotubes can be appreciably quenched by optically generated dipoles in PTB7 layer. This quenched PL provides further information to back up photodetectivity increasing through dipoles alignment in PTB7 layer.