Multidimensional Nanoscopic Approaches to New Thermoelectric Materials (Postprint)

The advantages of thermoelectric energy conversion technologies are briefly summarized. Recent material advances are discussed, with the focus on one-dimensional (1-D) self-assembled molecular materials as building blocks for new thermoelectric materials. The preparation, doping, and thermal characterization of phthalocyanine based materials are presented. The thermal conductivity of the doped material is orders of magnitude higher than the undoped material. This is counter intuitive against the backdrop of the Wiedemann-Franz treatment of thermal conductivity in electrical conductors from which one would expect thermal and electrical conductivity to both increase with introduction of additional charge carriers. These unusual results can be understood as a competition between the generation of an increased number of charge carriers and enhanced phonon scattering resulting from the introduction of chemical dopants.