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Page 24 of 33 Girase et al. Energy Mater. 2025, 5, 500132 https://dx.doi.org/10.20517/energymater.2025.14

Figure 8. (A) Comparative analysis of the progress in electrical conductivity and PF of DPP-based p-type thermoelectric polymers
reported over time and (B) Chemical structures of representative high-performance p-type thermoelectric polymers, showcasing key
structural features contributing to enhanced TE properties. PF: Power factor; TE: thermoelectric; DPP: diketopyrrolopyrrole.

shown in Figure 9B.

From the literature discussed, several strategies have been identified to overcome low TE performance.
Firstly, the synthesis of electron-deficient backbones such as DPP-based polymers lowers LUMO energy
levels and facilitates better n-doping thermodynamics. For instance, the DPP-based copolymer P(PzDPP-
-1
CT2) showed high σ of 8.4 S cm and PF of 57.3 μW m K , which indicates improved n-type doping
-2
-1
efficiency due to its well-structured molecular architecture. Second, dopant design advancements,
particularly with N-DMBI derivatives such as TP-DMBI and (N-DMBI) , have improved doping efficiency
2
through improved dopant-polymer miscibility, enhanced radical stability, and promotion of multielectron
transfer. Moreover, the unprecedented enhancement of n-type polymer TE performance by the design of
pDFSe with a noncovalently fused-ring structure with lower CCL 26.4 Å, higher paracrystalline disorder (g
= 21%), and more planar surface morphology. These features enhance doping efficiency so that pDFSe can
-1
show a high electron mobility of 6.15 cm V s and, upon n-doping, an exceptional σ of 62.6 S cm and a
-1 -1
2