Abstract:
It is generally deemed that doping is a must for polymeric materials to achieve their high thermoelectric performance. We herein present the first report that intrinsically metallic behaviors and high-performance thermoelectric power factors can coexist within doping-free linear-backbone conducting polymers, poly(nickel-ethylenetetrathiolate) and its analogs. On the basis of density functional calculations, we have corroborated that four
crystalline π-d conjugated transition-metal coordination polymers, including poly(Ni-C2S4), poly(Ni-C2Se4), poly- (Pd-C2S4) and poly(Pt-C2S4) exhibit intrinsically metallic
behavior arising from the formation of dense intermolecular interaction networks between sulfur/selenium atoms. They show moderate carrier concentrations (1019−1021 cm−3) and decent conductivities (103−104 S cm−1), among which,
poly(Ni-C2S4), poly(Ni-C2Se4) and poly(Pd-C2S4) possess high power factors (∼103 μW m−1 K−2).