SYNTHESIS OF WIDE BANDGAP CONJUGATED π-COPOLYMERS INCORPORATING 9H-CARBAZOL-3-YL DITHIENO[3,2-F:2',3'-H]QUINOXALINE UNITS VIA DIRECT ARYLATION POLYCONDENSATION FOR PHOTOVOLTAIC APPLICATIONтезисы докладаТезисы
Аннотация:We have designed new wide bandgap copolymer of A-D-A’-D type with strong carbazole-3-yl dithieno[3,2-f:2’,3’-h] quinoxaline and benzodithiophene-4,8-dione acceptors and thiophene donor unit denoted P1 and compared its optical and electrochemical properties with well-known copolymer PM6,3 which consists of same acceptor unit. The P1 exhibits deeper highest occupied molecular orbital and higher dipole moment than PM6, which is attributed to the weak donor unit in P1. Employing a narrow bandgap non-fullerene acceptor Y6, the organic solar cells based on P1 and PM6 under identical processing conditions showed overall power conversion efficiency of 13.48 and 14.81%, respectively. Although the power conversion efficiency of device based on P1 is lower than that for PM6, but its open circuit voltage is higher than that for PM6. Employing P1 as second donor, optimized ternary organic solar attained power conversion efficiency of 17.11%, which is higher than that for binary counterparts. The increased power conversion efficiency for ternary organic solar cells is associated with balanced charge transport, suppressed recombination process, faster charge extraction owing to the more appropriate morphology as well as the energy transfer from guest donor P1 to PM6.
