Bottom-up design of de novo thermoelectric hybrid materials using chalcogenide resurfacing

Abstract

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...

Development of Perovskite-Type Materials for Thermoelectric Application

“…We have studied the thermoelectric properties of PbTe films [20] and silver telluride nanofibers [41]. Additionally, Te nanostructures including nanowire [42], nanotree [42], and nanorice [43] were synthesized, which can be used to be embedded into other TE materials as nanocomposite [44,45,46] or converted to metal tellurides through cation exchange reaction [47,48]. Metal oxide materials, other than oxide perovskite materials, were investigated for TE application.…”

PEDOT:PSS/graphene quantum dots films with enhanced thermoelectric properties via strong interfacial interaction and phase separation

“…Highly conductive thermoelectric fillers have been used as dopants to increase the electrical conductivity to balance the power factor for greatly improving the thermoelectric properties of polymers, such as Ca 3 Co 4 O 9 16 , Te-Bi 2 Te 3 17 , Te 18 , graphene 19 , graphene oxide (GO) 20 , carbon nanotube 21 and reduced graphene oxide (RGO) 22 . Among these fillers, graphene group has better potential for its outstanding carrier mobility, strong mechanical properties, large specific surface area, and excellent chemical tolerance 23 – 25 .…”

Polymer morphology and interfacial charge transfer dominate over energy-dependent scattering in organic-inorganic thermoelectrics

“…Soft thermoelectric materials can realize flexible energy generation or heating-cooling devices with conformal geometries, enabling a new portfolio of applications for thermoelectric technologies 3 . Of particular interest are hybrid soft nanomaterials – an emerging material class that combines organic and inorganic components to yield fundamentally new properties 9–12 .…”