Dithienopicenocarbazole as the kernel module of low-energy-gap organic dyes for efficient conversion of sunlight to electricity

An electron-donor with a polycyclic aromatic hydrocarbon dithieno-[2',3': 2,3; 3 '',2 '': 10,11] piceno[1,14,13,12-bcdefgh]carbazole (DTPC) as the primary skeleton and also decorated with multiple solubilizing groups is coupled to 4-(benzo[c][1,2,5]thiadiazol-4-ylethynyl) benzoic acid, for a metal-free organic dye (C281). The near-infrared photosensitizing dye exhibits over 80% external quantum efficiency in a broad spectral range from 480 nm to 735 nm, and a high power conversion efficiency of 13.0% under irradiance of simulated AM 1.5G sunlight (100 mW cm(-2)).