Study of Phononic Contribution in Reduction of Thermal Conductivity of Nano scale Superlattice Structured Thermoelectric Materials

Thermoelectrics have been receiving attention for power generation from renewable sources and waste heat because of ever increasing global demand for cost-effective and pollution-free forms of energy conversion. High performance thermoelectric materials are in search for efficient thermoelectric conversion. Superlattices have extensively generated attention as promising materials to develop thermoelectric materials with high value of figure of merit. Previous researches show low value of thermal conductivity in the direction perpendicular to the planes of Nano scale superlattice structures due to the thermal transport. Phonons in the nano scale superlattice structures are the factor which are responsible for the thermal transport that do not reside in bulk thermoelectric materials. Size of nanostructured materials, phonon mean free path and phonon wavelength are the main factors for reducing lattice thermal conductivity. A brief discussion on the phonon engineering in thermoelectric materials of superlattice structure to reduce the lattice thermal conductivity of these materials, has been presented in this paper. The research works carried out by different researchers on development of efficient thermoelectric materials having low thermal conductivity has been thoroughly reviewed in this paper.