Three p-type thermoelectric (TE) polymers based on the indacenodithiophene moiety substituted with bis(alkylsulfanyl)methylene side-chains (IDTS) are synthesized. The TE characteristics of IDTS-based donor–donor’ (D–D′) type PIDTSDTTT and donor–acceptor (D–A) type polymers, PIDTSBT and PIDTS2FBT are investigated. Remarkably higher electrical conductivity (σ = ≈1000 S cm⁻¹) and power factor (PF = ≈120 μW m⁻¹ K⁻²) by doping with AuCl₃ are measured for PIDTSDTTT compared to D–A type polymers. The higher σ of PIDTSDTTT originates from its higher carrier concentration compared to those of PIDTSBT and PIDTS2FBT. Moreover, the facile polaron-to-bipolaron transition is measured, and the charge carriers are calculated to be more stable with extended delocalization in PIDTSDTTT compared to D–A polymers. The significantly higher doping stability in PIDTSDTTT can be explained in terms of the higher conduction band of bipolarons than the valence band of O₂ and H₂O, which blocks the facile reduction of bipolarons in air. The energetic structures of doped polaron and bipolaron states, as well as pristine TE polymers, must be carefully considered to realize efficient and stable p-type thermoelectric polymers, where a D–D′ type structure with further enhanced carrier mobility can be considered as a potential molecular framework.

中文翻译：

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基于茚并二噻吩的 D-D' 型热电聚合物具有显着的高电导率和功率因数

合成了三种基于被双（烷基硫烷基）亚甲基侧链（IDTS）取代的茚并二噻吩部分的 p 型热电（TE）聚合物。研究了基于IDTS的供体-供体'（D-D'）型PIDTSDTTT和供体-受体（D-A）型聚合物PIDTSBT和PIDTS2FBT的TE特性。通过掺杂AuCl ₃显着提高电导率（σ = ≈1000 S cm ^-1）和功率因数（PF = ≈120 μW m ^-1 K ^{-2 ）}与 D-A 型聚合物相比，测量 PIDTSDTTT。与 PIDTSBT 和 PIDTS2FBT 相比，PIDTSDTTT 较高的 σ 源于其较高的载流子浓度。此外，测量了容易的极化子到双极化子的跃迁，并且计算出与 D-A 聚合物相比，在 PIDTSDTTT 中扩展离域的电荷载流子更稳定。PIDTSDTTT 中显着更高的掺杂稳定性可以用双极子的导带高于 O ₂和 H _{2的价带来解释}O，它阻止了空气中双极子的轻松还原。必须仔细考虑掺杂极化子和双极化子态以及原始 TE 聚合物的能量结构，以实现高效且稳定的 p 型热电聚合物，其中载流子迁移率进一步增强的 D-D' 型结构可以被视为潜在的分子框架。