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Organic thermoelectric (OTE) materials promise convenient energy conversion between heat gradients and voltage with flexible and wearable power‐supplying devices at a low price. Although a variety of OTE materials are investigated, the TE performance is still far from practical application. To achieve high TE performance, a thorough understanding of the structure–property relationship in OTE materials is necessary. In this comprehensive review, the fundamentals of OTEs are summarized, the recent achievements of OTE materials are reviewed, and the relationship between structure and properties in high‐performance OTE materials is discussed. Furthermore, how the molecular backbones, side chains, energy levels, molecular packing, and heteroatom effect all play vital roles in thermoelectric properties is addressed. Finally, the future direction of research on OTE materials is envisaged. [ABSTRACT FROM AUTHOR]

[Display omitted] Thanks to the combined efforts of scientists in several research fields, the preceding decade has witnessed considerable progress in the use of conjugated polymers as emerging thermoelectric materials leading to significant improvements in performance and demonstration of a number of diverse applications. Despite these recent advances, systematic assessments of the impact of molecular design on thermoelectric properties are scarce. Although several reviews marginally highlight the role of chemical structure, the understanding of structure-performance relationships is still fragmented. An in-depth understanding of the relationship between molecular structure and thermoelectric properties will enable the rational design of next-generation thermoelectric polymers. To this end, this review showcases the state-of-the-art thermoelectric polymers, discusses structure-performance relationships, suggests strategies for improving thermoelectric performance that go beyond molecular design, and highlights some of the most impressive applications of thermoelectric polymers. [ABSTRACT FROM AUTHOR]

Doping plays a crucial role in modulating and enhancing the performance of organic semiconductor (OSC) devices. In this study, the critical role of dopants is underscored in shaping the morphology and structure of OSC films, which in turn profoundly influences their properties. Two dopants, trityl tetrakis(pentafluorophenyl) (TrTPFB) and N,N‐dimethylanilinium tetrakis(pentafluorophenyl)borate (DMA‐TPFB), are examined for their doping effects on poly(3‐hexylthiophene) (P3HT) and PBBT‐2T host OSCs. It is found that although TrTPFB exhibits higher doping efficiency, OSCs doped with DMA‐TPFB achieve comparable or even enhanced electrical conductivity. Indeed, the electrical conductivity of DMA‐TPFB‐doped P3HT reaches over 67 S cm−1, which is a record‐high value for mixed‐solution‐doped P3HT. This can be attributed to DMA‐TPFB inducing a higher degree of crystallinity and reduced structural disorder. Moreover, the beneficial impact of DMA‐TPFB on the OSC films' morphology and structure results in superior thermoelectric performance in the doped OSCs. These findings highlight the significance of dopant‐induced morphological and structural considerations in enhancing the film characteristics of OSCs, opening up a new avenue for optimization of dopant performance. [ABSTRACT FROM AUTHOR]