PSS-Te nanowires. This technique is shown to provide tunability of thermoelectric and electronic properties, providing up to 22% enhancement of the system's power factor in the low-doping regime, consistent with preferential scattering of low energy carriers. This work provides an exciting platform for rational design of multiphase nanocomposites and highlights the potential for engineering of carrier filtering within hybrid thermoelectrics via introduction of interfaces with controlled structural and energetic properties.

The inability to simultaneously manipulate the thermal and electronic properties of conventional thermoelectric materials independently has impeded their progress and broad penetration into terrestrial applications. Hybrid organic/inorganic thermoelectric materials based on conducting polymers and inorganic nanostructures hold the potential to utilize both the inherently low thermal conductivity of the polymer and the superior charge transport properties of the inorganic component. While there are several successful examples of such materials, there currently exists no general design strategy for generating hybrid thermoelectric materials. Here, we combine molecular engineering at the organic/inorganic interface and simple processing techniques to demonstrate a modular approach enabling de novo design of complex hybrid thermoelectric systems. We chemically modify the surfaces of inorganic nanostructures and graft conductive polymers to yield robust solution processable p-type and n-type inorganic/organic hybrid nanostructures. We tailor the thermoelectric properties of these hybrid materials by varying the composition of the organic and inorganic components and observe novel nonmonotonic behavior in the electronic properties due to strong chemical interactions between the components, which leads to peak thermoelectric performance at intermediate concentrations. Broader ContextTraditional composites of organic and inorganic materials demonstrate additive properties, which can be modeled by effective medium theories. However, a hybrid material offers remarkable nonlinear properties that cannot be captured by standard effective medium principles. While organic/inorganic composites have been extensively used for their improved mechanical properties, only recently have they been exploited across extremely diverse fields such as catalysis, coatings, fuel cells, optics, photovoltaics and microelectronics. With a plethora of chemical strategies that involve integrative syntheses and innovative chemical resurfacing at the nanoscale now readily available, one can design structurally well-defined and complex hybrid nano-architectures with improved and/or unusual properties. Unfortunately, due to intrinsic chemical and morphological incongruences between hard and soft components in hybrid thermoelectric materials, it has proven extremely challenging to exert simultaneous and effective control over both charge and heat transport. We demonstrate, for the first time, a streamlined synthetic approach that allows integration of complementary functionalities in a wide-gamut of inorganic-organic hybrid systems designed specifically for thermoelectric applications. Notably, across several materials combinations, we observe electronic properties in these hybrid systems that strongly deviate from those of the individual componentsowing to new transport physics that emerges from strong interactions manifest at the nanoscale interfaces between the parent constituent materials. These results highlight the importance of controlling and ma...

In this study, we present the first characterization of pure PEDOT:PSS aerogels fabricated via a facile and reproducible freeze–drying technique using no additional crosslinking agents, and it is demonstrated that these materials provide a promising path to new classes of polymeric thermoelectric materials. The morphology, chemical composition, and thermoelectric properties of these robust and mechanically stable aerogels were investigated upon treatment with ethylene glycol. By direct comparison to fully dense PEDOT:PSS thick films, it is shown that the electronic portion of thermoelectric transport in PEDOT:PSS was remarkably unaffected by morphological porosity, presenting exciting opportunities for novel soft materials that simultaneously integrate thermoelectric behavior while also capitalizing on the high surface area scaffolding accessible in such aerogel architectures. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44070.