Liao, Song FuSong FuLiaoChen, Chin TiChin TiChenCHI-YANG CHAO2019-09-252019-09-252017-09-192161-1653https://scholars.lib.ntu.edu.tw/handle/123456789/425101© 2017 American Chemical Society. To investigate the effect of substitution of cyano groups (CN) on D-π-A type conjugated copolymer in photophysical and photovoltaic properties, a non-CN-substituted P4TIH and a CN-substituted P4TIN isoindigo-based copolymers were synthesized and characterized. Having dicyano-substituted bithiophene as electron-donating segment and isoindigo as electron-accepting segment, P4TIN exhibits a deeper highest occupied molecular orbital energy level (HOMO) than that of the non-CN-substituted P4TIH. Benefiting from the improved solubility via copolymer side-chain substituent (2-decylteradecyl), inverted solar cells fabricated with a thick (∼200 nm) active layer (P4TIN:PC61BM, 1:2.0) have achieved a very high open circuit voltage of 1.06 V. High power conversion efficiency of 8.36% can be reached without thermal annealing treatment or processing solvent additives.[SDGs]SDG7Conversion efficiency; Molecular orbitals; Open circuit voltage; Organic polymers; Photovoltaic effects; Polymer solar cells; Timing circuits; Conjugated copolymers; Effect of substitution; High performance polymer; High power conversion; Highest occupied molecular orbital energy levels; Photovoltaic property; Power conversion efficiencies; Thermal annealing treatment; Solar cellsjournal article10.1021/acsmacrolett.7b005472-s2.0-85029700375WOS:000411653600015https://api.elsevier.com/content/abstract/scopus_id/85029700375