A diketopyrrolopyrrole-based small bandgap polymer (DPPT-TT) with high mobility is introduced as an additive to D–A1–D–A2 type thieno[3,4-b]thiophene-based random copolymer (P3):(6,6)-phenyl-C70-butyric acid methyl ester (PC71BM) polymer solar cells (PSCs).

No abstract

[3,4-g]thieno[3,2-c]-iso-quinoline-5,11-dione (TPTI), are synthesized and characterized. The comparative investigation of the photostabilities of the copolymers revealed that the PDTBDT-TPTI film exhibited the comparable photostability in relative to P3HT. Meanwhile, the inverted photovoltaic cells (i-PVCs) from the blend films of PBDT-TPTI and/or PDTBDT-TPTI with PC 71 BM, in which poly[(9,9-bis(3 0 -(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] were used as cathode modifying interlayer, presented higher power conversion efficiencies (PCEs) of 5.98% and 6.05% with photocurrent response ranging from 300 nm to 650 nm in contrast with the PCEs of 4.48% for the optimal inverted PVCs from P3HT/PC 71 BM under AM 1.5 G 100 mW/cm 2 . The PCEs of the i-PVCs from PBDT-TPTI and PDTBDT-TPTI were improved to 7.58% and 6.91% in contrast to that of 0.02% for the P3HT-based i-PVCs, and the photocurrent responses of the devices were extended to 300-792 nm, when the ITIC was used as electron acceptor materials. The results indicate that the PBDT-TPTI and PDTBDT-TPTI can be used as the promising alternatives of notable P3HT in the photovoltaic application. INTRODUCTION In last decades, the development of novel low band gap (LBG) donor conjugated polymers (CPs) has been demonstrated to be the most vigorous and promising approach to achieve high performance polymeric photovoltaic cells (PVCs), and various high performance LBG CPs have been presented. [1][2][3][4][5][6][7][8][9][10][11] Generally, the improvement of the short circuit current density (J sc ) can be achieved by narrowing the band gaps of the LBG CPs. Unfortunately, this approach usually compromised the trade-off problem such as the decrease of the open circuit voltage (V oc ) with the increase of the J sc of the PVCs from the LBG CPs. 12,13 To use solar radiation more effectively and achieve high performance

New soluble and intrinsic amorphous red emitters 1 and 2 were obtained by Suzuki coupling. Due to the close molecular polarities, separation of target products from monocoupling impurities presents a challenge. The results showed highly pure 2 would be a potentially valuable fluorophore for solution-processed pure red electroluminescence in terms of visual sensitivity with respect to 1.