A Carbonylated Terthiophene–Based Twisted Polymer for Efficient Ternary Polymer Solar Cells. Issue 19 (12th July 2019) - Xue, Changguo
Abstract: In polymer solar cells (PSCs), it is difficult for twisted conjugated polymers to achieve high power‐conversion efficiency (PCE) as donors due to their low charge carrier mobilities and poor bulk heterojunction morphologies. In this work, a new twisted conjugated polymer (P3TCO‐1) with excellent solubilities (above 30 mg mL −1 ) in common organic solvents at room temperature is reported. UV–visible absorption spectra and cyclic voltammetry indicate that P3TCO‐1 has a wide optical bandgap of 1.90 eV and deep HOMO level of −5.39 eV. In binary PSCs, P3TCO‐1:ITIC‐based device shows a PCE of 10.11%, with J SC of 17.05 mA cm −2 and FF of 62.89%; P3TCO‐1:PC71 BM‐based device gives a PCE of 6.67% with J SC of 12.31 mA cm −2 and FF of 58.00%. When the two acceptors of ITIC and PC71 BM are combined, the twisted P3TCO‐1‐based ternary PSCs exhibit a significantly boosted PCE of up to 11.41%, with a simultaneously improved J SC of 18.16 mA cm −2 and FF of 66.78%. These results can guide the improvement of PCE for twisted conjugated polymer‐based PSCs. Abstract : A twisted conjugated polymer P3TCO‐1 is designed and synthesized. In binary PSCs, P3TCO‐1:ITIC and P3TCO‐1:PC71 BM‐based photovoltaic devices give decent power conversion efficiencies (PCEs) of 10.11% and 6.67%, respectively. After the introduction of PC71 BM as the third component into a P3TCO‐1:ITIC blend, the corresponding ternary photovoltaic device achieves a PCE of up to 11.41%.