Effect of electron-phonon interaction on the room temperature thermoelectric properties of bulk MoSe2MoSe_2

We study the thermoelectric properties of bulk $MoSe_2$ within relaxation time approximation including electron-phonon and ionized impurity interactions using first-principles calculations and at room temperatures. The anisotropy of this two-dimensional layered metal dichalcogenide is studied by calculations of electron mobility in the cross-plane and the in-plane directions. We show that the cross-plane mobility is two orders of magnitude smaller than the in-plane one. The inclusion of van der Waals interactions further lowers the carrier mobility in the cross-plane direction but minimally affects the in-plane one. The results for in-plane electrical mobility and conductivity are in close agreement with experimentally reported values indicating the accuracy of the calculations and the dominance of the electron-phonon scattering rates at low carrier concentrations and the combination of electron-phonon and ionized impurity scattering at high carrier concentrations. The Seebeck coefficient calculations show that this coefficient is primarily dictated by the band structure. The details of relaxation times and inclusion of van der Waals interactions only slightly change the Seebeck coefficient

Combinatorial approach to identify electronically cloaked hollow nanoparticles

The possibility of designing core-shell nanoparticles that are “invisible” to the conduction electrons has been demonstrated recently. A total scattering cross section smaller than 0.01% of the physical cross section was demonstrated by artificially adjusting the parameters of the barrier and the well in a core-shell geometry. In this paper, we aim to extend the developed concept and find realistic material combinations that satisfy the cloaking criteria. We report designs of hollow nanoparticles that could be used to realize the cloaking concept in III–V semiconductor host matrices. Such particles could be used in advanced materials design to enhance and tune the electrical and the thermoelectric properties of a given host matrix. This paper may also contribute to defect engineering by coating defect sites with a proper cloaking layer.United States. Dept. of Energy. Office of Basic Energy Sciences (Award DE-FG02-09ER46577