Physics of large thermoelectric power factors in SnSe nanoflakes in mid-temperature range.

We have theoretically investigated the underlying physics of observed high electrical conductivity (), simultaneous increase of σ and Seebeck coefficient () with temperature, and large power factors (PFs) in nominally undoped SnSe nanoflakes sintered at different temperatures, reported recently in Mandava(2022155710). Given the fact that S and σ show unusual temperature trends and that the undoped SnSe samples are highly porous and disordered, the conventional Boltzmann theory does not appear to be an appropriate model to describe their transport properties. We have, instead, used a strong disorder model based on percolation theory where charge and energy transport take place through hopping between localized states to understand these observations.

Investigating the key role of carrier transport mechanism in SnSe nanoflakes with enhanced thermoelectric power factor.

A novel SnSe nanoflake system is explored for its thermoelectric properties from both experiments andstudy. The nanoflakes of the low temperature phase of SnSe (Pnma) are synthesized employing a fast and efficient refluxing method followed by spark plasma sintering at two different temperatures. We report an enhanced power factor (12-67W mKin the temperature range 300-600 K) in our p-type samples.

Probing the path for achieving a broad temperature plateau of the figure of merit in thermoelectric nanocomposite materials.

The efficiency of a thermoelectric device depends directly on the average figure of merit (zT) of the material. A high average zT requires a broad temperature plateau with a high zT, but state-of-the-art thermoelectric materials display a peaked zT over a narrow temperature range due to a strong temperature dependence of transport properties. In this work, using Boltzmann transport theory, we systematically investigate the underlying physics and propose a strategy for attaining a broad temperature plateau of zT through proper engineering of the interfacial barrier height in PbTe nanocomposite material.