First-principles analysis of ZrN/ScN metal/semiconductor superlattices for thermoelectric energy conversion

Saha, Bivas ; Sands, Timothy D. ; Waghmare, Umesh V. (2011) First-principles analysis of ZrN/ScN metal/semiconductor superlattices for thermoelectric energy conversion Journal of Applied Physics, 109 (8). 083717_1-083717_7. ISSN 0021-8979

Full text not available from this repository.

Official URL: http://jap.aip.org/resource/1/japiau/v109/i8/p0837...

Related URL: http://dx.doi.org/10.1063/1.3569734

Abstract

We present a first-principles density functional theory-based analysis of the electronic structure, vibrational spectra, and transport properties of ZrN/ScN metal/semiconductor superlattices aiming to understand its potential and suitability for thermoelectric applications. We demonstrate (a) the presence of Schottky barriers of 0.34 eV at the metal/semiconductor interface and (b) a large asymmetry in the electronic densities of states and flattening of electronic bands along the cross-plane directions near the Fermi energy of these superlattices, desirable for high Seebeck coefficient. The vibrational spectra of these superlattices show softening of transverse acoustic phonon modes along the growth direction and localization of ScN phonons in the vibrational energy gap between metal and semiconductor layers. Boltzmann transport theory-based analysis suggests a reduction of lattice thermal conductivity by an order of magnitude compared to its individual bulk components, which makes these materials suitable for thermoelectric applications.

Item Type:Article
Source:Copyright of this article belongs to American Institute of Physics.
Keywords:Ab Initio Calculations; Boltzmann Equation; Density Functional Theory; Direct Energy Conversion; Electronic Density of States; Energy Gap; Fermi Level; Metallic Superlattices; Phonons; Scandium Compounds; Schottky Barriers; Seebeck Effect; Semiconductor Materials; Semiconductor Superlattices; Semiconductor-metal Boundaries; Soft Modes; Thermal Conductivity; Transport Processes; Zirconium Compounds
ID Code:89903
Deposited On:02 May 2012 13:24
Last Modified:02 May 2012 13:24

Repository Staff Only: item control page