Multi length scale porosity as a playground for organic thermoelectric applications

Abstract

Porous organic materials have interesting materials properties governed not only by their covalent structure but also by their intrinsic porosity which when controlled over multiple length scales gives rise to micro-, meso- and macroporous materials. These materials have been exploited for many years in applications such as gas storage, filtration/separation membranes, or support for catalysts. More recently, porous materials have attracted significant attention as potential harvesters of the abundant waste heat generated in today's society. Taking advantage of the thermoelectric effect, whereupon a temperature gradient is converted to electric voltage, thermoelectric materials and their associated applications are well-suited for this endeavor. Efficient thermoelectric materials must combine a high electrical conductivity and a low thermal conductivity. Since in porous materials, these properties can potentially be optimized independently, they are intriguing candidates for further exploration. Here, we give an overview of the different classes of porous conducting polymers (PCPs) and provide a thorough survey of their recent use in the broader context of thermoelectrics. We also aim to identify the major challenges and future perspectives for porous organic thermoelectric materials.