Harvesting Waste Heat with Molecular Precision: The role of Metal-Organic Coordination Polymers for Sustainable Organic Thermoelectrics

Abstract

Organic thermoelectrics enable harvesting of low-grade heat using mechanically compliant materials with intrinsically low thermal conductivity. However, predictive materials design remains challenging due to structural disorder, mixed transport mechanisms, and poorly defined carrier densities, limitations that are especially acute for air-stable n-type systems. Metal-organic coordination polymers (MOCPs) offer a chemistry-defined alternative: their periodic metalligand motifs allow for relating coordination descriptors, such as ligand field strength, coordination geometry, counter-ions, and stacking motifs, onto electronic and phonon metrics that control thermoelectric performance. Here, we establish structure-aware design principles that connect (i) π-d or π-π hybridization as well as backbone planarity to band dispersion and effective mass, (ii) ion intercalation and redox chemistry to carrier type and concentration, and (iii) crystallinity, dimensionality, and interfacial effects to the evolution of thermal conductivity under doping. Using poly(M-dithiolene) and related MOCP families as representative case studies, we outline a theory-to-device workflow that couples first-principles calculations, 2 multiscale transport modelling, and standardized anisotropic measurements, and we benchmark performance targets against recent flexible thermoelectric generators.