“…28 Subsequently, the PCE was increased to 3.04% when choosing PBDTTT-C-T as the donor in 2014 and then was continuously maximized to 3.49% when matched with donor BDDT in 2017. 29,30 Assisted by the design idea of the welldeveloped PDs, substantial efforts devoted to constructing donor-acceptor (D-A) structured alternating conjugated polymers (CPs) via coupling with numerous electron-rich units, i.e., vinylene (V), 26,27,31 fluorene (F), [31][32][33] carbazole (Cz), 31,32 benzo[1,2-b:4,5-b 0 ]dithiophene (BDT), [33][34][35][36] naphtho[1,2-b:5,6b 0 ]dithiophene (NDT), 36 thiophene (T), 25,31,37,38 selenophene (Se), 37,39 tellurophene (Te), 40 bithiophene (2T), [41][42][43] thieno[3,2b]thiophene (TT), [36][37][38] thienylenevinylene (TVT), 44 31 and so on. Apparently, among these PDI-based D-A type CPs, thiophene, tellurophene and vinylene building blocks possessing relatively small volume cubage exhibited an excellent PCE of over 6% (Table S1, ESI †).…”