An extremely narrow band gap conjugated polymer for photovoltaic devices covering UV to near-infrared light

An alternating narrow band gap conjugated polymer derived from 4,6-bis(4-tetradecylthien-2-yl)thieno[3,4-c]thiadiazole and thieno[3,2-b]thiophene, was synthesized by Stille coupling reaction, and named as PDTTZ-TT. Photovoltaic devices from the PDTTZ-TT and fullerene derivatives exhibit light response from 300 nm to 1260 nm. The specific detectivity of the devices was reached to 1.68-7.66 × 1012 Jones under zero bias. As we have known, it is one of the best reported sensitivity for polymer photodetectors with light response covering UV-Vis to near-infrared light.304