N Ganesan

Bio: N Ganesan is an academic researcher. The author has contributed to research in topics: Charge carrier & Seebeck coefficient. The author has an hindex of 1, co-authored 1 publications receiving 2 citations.

Evidence for the domination of heavy holes and lattice scattering in SnTe from electrical transport measurements on polycrystalline thin films

Abstract: The influence of temperature and thickness on the electrical resistivity and Seebeck coefficient of polycrystalline SnTe thin films was investigated in detail. The size effect data for the electrical resistivity and Seebeck coefficient fit very well with Tellier's effective mean free path model. Different physical parameters such as Fermi energy (EF) and effective mass (m*) were evaluated. From this it is concluded that heavy holes are the dominant charge carriers. The Seebeck coefficient data were also fitted into the Jain-Verma expression to evaluate the scattering parameter (b) and the value of b clearly indicates the dominance of lattice scattering in SnTe.

High thermoelectric performance by resonant dopant indium in nanostructured SnTe

Abstract: From an environmental perspective, lead-free SnTe would be preferable for solid-state waste heat recovery if its thermoelectric figure-of-merit could be brought close to that of the lead-containing chalcogenides. In this work, we studied the thermoelectric properties of nanostructured SnTe with different dopants, and found indium-doped SnTe showed extraordinarily large Seebeck coefficients that cannot be explained properly by the conventional two-valence band model. We attributed this enhancement of Seebeck coefficients to resonant levels created by the indium impurities inside the valence band, supported by the first-principles simulations. This, together with the lower thermal conductivity resulting from the decreased grain size by ball milling and hot pressing, improved both the peak and average nondimensional figure-of-merit (ZT) significantly. A peak ZT of ∼1.1 was obtained in 0.25 atom % In-doped SnTe at about 873 K.