N → B Ladder Polymers Prepared by Postfunctionalization: Tuning of Electron Affinity and Evaluation as Acceptors in All-Polymer Solar Cells
N → B Ladder Polymers Prepared by Postfunctionalization: Tuning of Electron Affinity and Evaluation as Acceptors in All-Polymer Solar Cells
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DOI：
10.1021/acs.macromol.8b02595
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发表时间：
2019-02-12
期刊：
影响因子：
5.5
通讯作者：
Pammer, Frank
中科院分区：
文献类型：
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作者：
Grandl, Markus;Schepper, Jonas;Pammer, Frank
聚（联苯亚基-吡嗪亚基）（PPz，E-g（opt）= 3.10 eV）和头-尾区域规则的多吡啶已经制备了配备有1-烯基侧链的（rr-P4Py，E-g（opt）= 3.25 eV），并通过用不同的氢硼烷进行硼氢化来后官能化（9 H-BBN，（C6 F5）（2）B-H（BPF-H），C12 B-H），得到了相应的梯形聚合物，其分子内具有N -> B配位键。后官能化聚合物的光学和电化学性质的表征表明，硼基化强烈地增加了它们的电子亲和势，降低了光学带隙。电子亲合势在-3.7S eV之间（PPzBBN，E-g（opt）= 2.16 eV）和-4.35 eV（PPzBPF，E-g（opt）= 2.07 eV）可以硼氢化PPz，而rr-P4Py衍生物达到-3.45 eV的LUMO能级88eV）、-3.85eV（P4PyBPF，E-g（opt）= 2.95eV）和-4.15eV（P4PyBC1（2），E-g（opt）= 2.95eV）。通过对PPzBBN和PPzBPF的半导体性质的研究，证明了这类化合物作为电子受体的潜力，其显示出空穴和电子迁移率为2 × 10（-5）cm（2）s（-1）的双极电荷传输。这些聚合物在全聚合物太阳能电池中作为受体进行了测试，这产生了功能器件，开路电压直接反映了所用受体的电子亲和力。
A poly(biphenylene-pyrazinylene) (PPz, E-g(opt) = 3.10 eV) and a head-to-tail regioregular polypyridine (rr-P4Py, E-g(opt) = 3.25 eV) equipped with 1-alkenyl side chains have been prepared and postfunctionalized by hydroboration with different hydroboranes (9H-BBN, (C6F5)(2)B-H (BPF-H), C12B-H) to give the corresponding ladder polymers featuring intramolecular coordinative N -> B bonds. Characterization of the optical and electrochemical properties of the postfunctionalized polymers shows that the borylation strongly increases their electron affinity and lowers the optical gaps. Electron affinities between -3.7S eV (PPzBBN, E-g(opt) = 2.16 eV) and -4.35 eV (PPzBPF, E-g(opt) = 2.07 eV) can hydroborated PPz, while rr-P4Py-derivatives reach LUMO levels of -3.45 eV (P4PyBBN, E-g(opt) = 2.88 eV), -3.85 eV (P4PyBPF, E-g(opt) = 2.95 eV), and -4.15 eV (P4PyBCl(2), = 2.95 eV). The potential of this class of compounds as electron acceptors is demonstrated by the investigation of the semiconducting properties of PPzBBN and PPzBPF, which showed ambipolar charge transport with hole and electron mobilities in order of 2 X 10(-5) cm(2) s(-1). The polymers were tested as acceptors in all-polymer solar cells, which yielded functioning devices, with open-circuit voltages that directly reflect the electron affinity of the employed acceptor.