A series of metal coordination polymers containing 1,1,2,2-ethenetetrathiolate (ett) linking bridge (poly[Ax(M-ett)]) are synthesized. The Seebeck coefficients of these conducting materials are high, and vary according to the center metals and counter cations. The TE device fabricated demonstrates the great potentials of these materials for TE applications.

Flexible thin films of poly(nickel-ethylenetetrathiolate) prepared by an electrochemical method display promising n-type thermoelectric properties with the highest ZT value up to 0.3 at room temperature. Coexistence of high electrical conductivity and high Seebeck coefficient in this coordination polymer is attributed to its degenerate narrow-bandgap semiconductor behavior.

Heat is an abundant but often wasted source of energy. Thus, harvesting just a portion of this tremendous amount of energy holds significant promise for a more sustainable society. While traditional solid-state inorganic semiconductors have dominated the research stage on thermal-to-electrical energy conversion, carbon-based semiconductors have recently attracted a great deal of attention as potential thermoelectric materials for low-temperature energy harvesting, primarily driven by the high abundance of their atomic elements, ease of processing/manufacturing, and intrinsically low thermal conductivity. This quest for new materials has resulted in the discovery of several new kinds of thermoelectric materials and concepts capable of converting a heat flux into an electrical current by means of various types of particles transporting the electric charge: (i) electrons, (ii) ions, and (iii) redox molecules. This has contributed to expanding the applications envisaged for thermoelectric materials far beyond simple conversion of heat into electricity. This is the motivation behind this review. This work is divided in three sections. In the first section, we present the basic principle of the thermoelectric effects when the particles transporting the electric charge are electrons, ions, and redox molecules and describe the conceptual differences between the three thermodiffusion phenomena. In the second section, we review the efforts made on developing devices exploiting these three effects and give a thorough understanding of what limits their performance. In the third section, we review the state-of-the-art thermoelectric materials investigated so far and provide a comprehensive understanding of what limits charge and energy transport in each of these classes of materials.

The evolution of our society is characterized by an increasing flow of information from things to the internet. Sensors will become the corner stone of internet-of-everything as they track various parameters in our society and sent them to the cloud for analysis, forecast or learning.With the many parameters to sense, sensors are becoming complex and difficult to manufacture.To reduce the complexity of manufacturing, one can instead create advanced functional materials that react to multiple stimuli. To this end, conducting polymer aerogels are promising materials as they combine elasticity and sensitivity to pressure and temperature and they could eventually be functionalized further with chemical and biosensing molecules. However, the challenge is to read independently pressure and temperature output signal without cross-talk of these parameters. Here, we demonstrate a strategy to fully decouple temperature and pressure reading in a dual-parameter sensor based on thermoelectric polymer aerogels. We found that aerogels made of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) can display either semiconducting or close to semimetallic properties upon exposure to high boiling point polar solvents, such as dimethylsulfoxide (DMSO). As DMSO acts as a secondary dopant, the conductivity of the PNG aerogel can be increased by more than two orders of magnitude, resulting into greatly enhanced pressure sensitivity. Importantly, because of the temperatureindependent charge transport observed for DMSO-treated PEDOT-based aerogel, a decoupled

In this article, we put forward a simple method for the synthesis of thermoelectric (TE) composite materials. Both n- and p-type composites were obtained by ball-milling the insoluble and infusible metal coordination polymers with other polymer solutions. The particle size, film morphology and composition were characterized by dynamic light scattering, scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy. The TE properties of the drop-cast composite film were measured at different temperatures. An inkjet-printed flexible device was fabricated and the output voltage and short-circuit current at various hot-side temperatures ( T hot ) and temperature gradients (Δ T ) were tested. The composite material not only highly maintained the TE properties of the pristine material but also greatly improved its processability. This method can be extended to other insoluble and infusible TE materials for solution-processed flexible TE devices.

NFC–PSSNa composite paper combines high ionic conductivity, high ionic Seebeck coefficient and low thermal conductivity, resulting in an overall slightly better figure-of-merit than PSSNa.

Low‐cost, non‐toxic, abundant organic thermoelectric materials are currently under investigation for use as potential alternatives for the production of electricity from waste heat. While organic conductors reach electrical conductivities as high as their inorganic counterparts, they suffer from an overall low thermoelectric figure of merit (ZT) due to their small Seebeck coefficient. Moreover, the lack of efficient n‐type organic materials still represents a major challenge when trying to fabricate efficient organic thermoelectric modules. Here, a novel strategy is proposed both to increase the Seebeck coefficient and achieve the highest thermoelectric efficiency for n‐type organic thermoelectrics to date. An organic mixed ion–electron n‐type conductor based on highly crystalline and reduced perylene bisimide is developed. Quasi‐frozen ionic carriers yield a large ionic Seebeck coefficient of −3021 μV K−1, while the electronic carriers dominate the electrical conductivity which is as high as 0.18 S cm−1 at 60% relative humidity. The overall power factor is remarkably high (165 μW m−1 K−2), with a ZT = 0.23 at room temperature. The resulting single leg thermoelectric generators display a high quasi‐constant power output. This work paves the way for the design and development of efficient organic thermoelectrics by the rational control of the mobility of the electronic and ionic carriers.

Organic photothermoelectric (PTE) materials are promising candidates for various photodetection applications. Herein, we report on poly[Cux(Cu-ett)]:PVDF, which is an excellent polymeric thermoelectric composite, possesses unprecedented PTE properties. The NIR light irradiation on the poly[Cu(x)(Cu-ett)]:PVDF film could induce obvious enhancement in Seebeck coefficient from 52 ± 1.5 to 79 ± 5.0 μV/K. By taking advantage of prominent photothermoelectric effect of poly[Cu(x)(Cu-ett)]:PVDF, an unprecedented voltage of 12 mV was obtained. This excellent performance enables its promising applications in electricity generation from solar energy and NIR detection to a wide range of light intensities ranging from 1.7 mW/cm(2) to 17 W/cm(2).