Copolymerization towards obtaining full visible light absorption is highlighted. Randomly distributed segments of different oligomers resulted in neutral state black copolymers. Solution processability and highly transmissive gray oxidized states make copolymers great candidates to be used in low cost flexible organic electronics.

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Two donor/acceptor/donor‐type pyrrole‐incorporated monomers, 4,7‐di(1H‐pyrrol‐2‐yl)benzo[c][1,2,5]thiadiazole (M1) and 4,7‐di(1H‐pyrrol‐2‐yl)benzo[c][1,2,5]selenadiazole (M2), were synthesized and polymerized electrochemically. The resulting polymers (P1 and P2) were investigated in terms of their electrochromic and optical properties. Spectroelectrochemistry studies revealed that both polymers show two distinct absorptions in both red and blue regions. The absorptions at around 400 and 700 nm correspond to neutral‐state green polymers P1 and P2, which is a unique property for conjugated polymers. Optical band gaps were calculated as 1.12 and 1.08 eV for P1 and P2, respectively. magnified image

High refractive index (HRI) materials play an important role in optic‐electronic devices. In this study, two compounds with high content of naphthalene groups, 1,5‐dithiolnaphthalene and 1,3,5‐tris(naphthalyl–ethylnyl) benzene, are selected as “A2” and “B3” monomers, respectively to prepare hyperbranched HRI polymers. Metal‐free radical‐initiated “A2 + B3” thiol‐yne polyaddition is conducted successfully at different monomer molar ratios even for those sterically demanding molecules being able to adjust the molar mass as well as RI. Polymers with refractive index up to 1.79 at 589.7 nm are obtained, which are among the highest RI values so far reported for pure polymer‐based materials. The high RI, based on the high molar refraction of naphthalene group, metal‐free and easy one‐pot synthesis, high transparency in the visible area, good thermal stability, good solubility, and easy processability into thin films, make these polymers excellent candidates for optic‐electronic applications.