Solution-processed near-infrared organic photodetector based on a liquid crystalline phthalocyanine derivative for vital signal monitoring

Abstract In this study, near-infrared (NIR) organic photodetectors (OPDs) based on a liquid crystalline phthalocyanine derivative, 1,4,8,11,15,18,22,25-octaoctyl-phthalocyanine (8H 2 Pc), and phenyl-C61-butyric acid methyl ester (PC 61 BM) were realized. The best device had blend ratio of 1:1 by weight exhibited responsivity 0.2 A W −1 , external quantum efficiency 29% shot-noise-limited specific detectivity 1.3 × 10 12 Jones at 740 nm with V reverse bias. This notable performance was attributed to the uniformity smooth surface morphology spin-coated active layer intermixed condition 8H Pc PC BM, resulting in smaller domain sizes better separation photogenerated exciton pairs. Finally, future prospects realized NIR OPD practical applications demonstrated monitoring vital signals human subject very simple experimental setup.