3,4,5‐Trimethoxy Substitution on an N‐DMBI Dopant with New N‐Type Polymers: Polymer‐Dopant Matching for Improved Conductivity‐Seebeck Coefficient Relationship
3,4,5‐Trimethoxy Substitution on an N‐DMBI Dopant with New N‐Type Polymers: Polymer‐Dopant Matching for Improved Conductivity‐Seebeck Coefficient Relationship
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用新型 N-型聚合物对 N-DMBI 掺杂剂进行 3,4,5-三甲氧基取代：聚合物-掺杂剂匹配以改善电导率-塞贝克系数关系
DOI：
10.1002/anie.202110505
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Katz, Howard E.
中科院分区：
文献类型：
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作者：
Han, Jinfeng;Chiu, Arlene;Ganley, Connor;McGuiggan, Patty;Thon, Susanna M.;Clancy, Paulette;Katz, Howard E.
同时实现n型有机热电体的高电导率和热电功率因数仍然具有挑战性。通过构建两种新的具有不同主链的受体-受体n型共轭聚合物，并引入3，4，5-三甲氧基苯基形成新的n型掺杂剂1，3-二甲基-2-（3，4，5-三甲氧基苯基）-2，3-二氢-1H-苯并[d]咪唑（TP-DMBI），获得了11 S cm− 1的高电导率和32 μW m− 1 K − 2的功率因数。 使用密度泛函理论的计算表明，TP-DMBI呈现出比常见掺杂剂4-（1，3-二甲基-2，3-二氢-1H-苯并咪唑-2-基）苯基）二甲胺（N-DMBI）（−2.36 eV）更高的单占据分子轨道（SOMO）能级（−1.94 eV），这可能导致掺杂剂的SOMO与n型聚合物的最低未占分子轨道（LUMO）之间更大的偏移，尽管这种效应在本工作中可能不是主导的。 掺杂的聚合物膜表现出比在相同掺杂水平或类似电导率水平下使用N-DMBI的膜更高的塞贝克系数和功率因数。此外，TP-DMBI掺杂的聚合物薄膜提供了比N-DMBI掺杂的薄膜高得多的电子迁移率，高达0.53 cm 2 V − 1 s − 1，这表明TP-DMBI和3，4，5-三烷氧基DMBI更广泛地用于高性能n型有机热电器件的潜力。
Achieving high electrical conductivity and thermoelectric power factor simultaneously for n‐type organic thermoelectrics is still challenging. By constructing two new acceptor‐acceptor n‐type conjugated polymers with different backbones and introducing the 3,4,5‐trimethoxyphenyl group to form the new n‐type dopant 1,3‐dimethyl‐2‐(3,4,5‐trimethoxyphenyl)‐2,3‐dihydro‐1H‐benzo[d]imidazole (TP‐DMBI), high electrical conductivity of 11 S cm−1and power factor of 32 μW m−1K−2are achieved. Calculations using Density Functional Theory show that TP‐DMBI presents a higher singly occupied molecular orbital (SOMO) energy level of −1.94 eV than that of the common dopant 4‐(1, 3‐dimethyl‐2, 3‐dihydro‐1H‐benzoimidazol‐2‐yl) phenyl) dimethylamine (N‐DMBI) (−2.36 eV), which can result in a larger offset between the SOMO of dopant and lowest unoccupied molecular orbital (LUMO) of n‐type polymers, though that effect may not be dominant in the present work. The doped polymer films exhibit higher Seebeck coefficient and power factor than films using N‐DMBI at the same doping levels or similar electrical conductivity levels. Moreover, TP‐DMBI doped polymer films offer much higher electron mobility of up to 0.53 cm2V−1s−1than films with N‐DMBI doping, demonstrating the potential of TP‐DMBI, and 3,4,5‐trialkoxy DMBIs more broadly, for high performance n‐type organic thermoelectrics.