Flexible Organic Thermoelectric Nanocomposites: Transport Properties and Applications

Thermoelectric materials which can realize direct energy conversion between heat and electricity are used for solid-state energy harvesting or local cooling. Classically, various inorganic compounds based on Te and Pb have been considered as excellent thermoelectric materials due to their high electrical conductivity and Seebeck coefficient. Apart from inorganic materials, thermoelectric polymers are receiving great attention because of their low density, low cost of fabrication, mechanical flexibility, and low or no chemical toxicity. The energy conversion efficiency of organic thermoelectric materials has been greatly improved and is now even comparable to inorganic compounds. This article provides the recent progress of organic thermoelectric composites. Herein, organic nanocomposites with conductive carbonaceous fillers are discussed. It focuses on the strategies for enhancing thermoelectric performances with commonly used conjugated polymers, the influence of nanofiller network structures on electrical and thermal properties, and doping/de-doping techniques of organic composites. In addition, the applications of modularized organic energy harvesters are also given.