Electrochromic and optical studies of solution processable benzotriazole and fluorene containing copolymers

2-Dodecyl benzotriazole and 9,9-dioctylfluorene containing alternating copolymers poly((9,9-dioctylfluorene)-2,7-diyl-(2-dodecyl-benzo[1,2,3]triazole)) (P1), poly((9,9-dioctylfluorene)-2,7-diyl-(4,7-bis(thien-2-yl) 2-dodecyl-benzo[1,2,3]triazole)) (P2), poly((9,9-dioctylfluorene)-2,7-diyl-(4,7-bis(3-hexylthien-5-yl) 2-dodecyl-benzo[1,2,3]triazole)) (P3) were synthesized via Suzuki polycondensation. Electronic and optical properties of resulting polymers showed that all polymers are both p and n dopable and have multicolored electrochromic states. HOMO and LUMO values, band gaps and spectral response of polymers upon externally applied potential and trifluoro acetic acid (TFA) addition were given in detail.

Benzotriazole and fluorene containing alternating copolymers are found to be both n and p dopable with multicolored electrochromic states.Figure optionsDownload as PowerPoint slideResearch highlights
► Fluorene and BTz-based copolymers were synthesized via Suzuki polycondensation.
► Their electrochromic and optical properties were investigated in detail.
► Multichromic, both p and n type polymers were achieved in different states.
► Solution doping of the polymers also revealed different colors.
► These copolymers can be used as active layers in OPVs and OLEDs.