Deng Sihui, Kuang Yazhuo, Liu Liyao, Liu Xinyu, Liu Jian, Li Jingyu, Meng Bin, Di Chong-An, Hu Junli, Liu Jun
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China.
School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, P. R. China.
Adv Mater. 2024 Feb;36(8):e2309679. doi: 10.1002/adma.202309679. Epub 2023 Dec 10.
The ability of n-type polymer thermoelectric materials to tolerate high doping loading limits further development of n-type polymer conductivity. Herein, two alcohol-soluble n-type polythiophene derivatives that are n-PT3 and n-PT4 are reported. Due to the ability of two polymers to tolerate doping loading more significantly than 100 mol%, both achieve electrical conductivity >100 S cm . Moreover, the conductivity of both polythiophenes remains almost constant at high doping concentrations with excellent doping tunability, which may be related to their ability to overcome charging-induced backbone torsion and morphology change caused by saturated doping. The characterizations reveal that n-PT4 has a high doping level and carrier concentration (>3.10 × 10 cm ), and the carrier concentration continues to increase as the doping concentration increases. In addition, doping leads to improved crystal structure of n-PT4, and the crystallinity does not decrease significantly with increasing doping concentration; even the carrier mobility increases with it. The synergistic effect of these two leads to both n-PT3 and n-PT4 achieving a breakthrough of 100 in conductivity and power factor. The DMlmC-doped n-PT4 achieves a power factor of over 150 µW m K . These values are among the highest for n-type organic thermoelectric materials.
n型聚合物热电材料耐受高掺杂负载的能力限制了n型聚合物导电性的进一步发展。在此，报道了两种醇溶性n型聚噻吩衍生物，即n-PT3和n-PT4。由于这两种聚合物耐受掺杂负载的能力明显超过100 mol%，二者的电导率均大于100 S cm 。此外，两种聚噻吩在高掺杂浓度下的电导率几乎保持恒定，具有出色的掺杂可调性，这可能与其克服由饱和掺杂引起的电荷诱导主链扭转和形态变化的能力有关。表征结果表明，n-PT4具有高掺杂水平和载流子浓度（>3.10×10 cm ），并且载流子浓度随着掺杂浓度的增加而持续增加。此外，掺杂使n-PT4的晶体结构得到改善，结晶度不会随着掺杂浓度的增加而显著降低；甚至载流子迁移率也随之增加。这两者的协同效应导致n-PT3和n-PT4在电导率和功率因数方面均实现了100的突破。用DMlmC掺杂的n-PT4的功率因数超过150 μW m K 。这些值在n型有机热电材料中是最高的之一。
