Quasicrystals and the Quest for Next Generation Thermoelectric Materials

Since the lattice thermal conductivity of most thermoelectric materials of interest has already been greatly reduced, next generation bulk thermoelectric materials will rely on the ability to properly tailor the electronic band structure in the vicinity of the Fermi level in order to optimize their thermoelectric performance. To this end, a main theoretical goal focuses on obtaining a fundamental guiding principle, able to properly replace previous methods in terms of a band structure engineering approach. Following this approach in this review we will consider the case of quasicrystals: a class of materials based on new lattice geometries, characterized by scale-invariance symmetry and long-range aperiodic order. As a consequence, quasicrystalline alloys exhibit semiconductor-like, rather than metallic electronic transport properties, along with extremely low thermal conductivity values. Thus, quasicrystals occupy a very promising position in the quest for novel thermoelectric materials, naturally bridging the gap between semiconducting materials and metallic ones. Accordingly, by keeping into account both experimental data and solid state physics theoretical aspects, we will provide a prospective study on the potential use of quasicrystals and their related phases in actual thermoelectric devices in the years to come.