Year: 2018
Type: article
Abstract: Quasi-two dimensional nano-structures are characterized by radical changes in electron and phonon properties. Electron behavior in Q-2D nano-structures is modified by the presence of multiple sub-bands. For well widths smaller than 50 Å simplified model calculations based on the assumption of electrons occupying the lowest sub-band appears to be quite reasonable. For larger width others, parabolic sub-bands need to be considered. The present paper investigates the thermoelectric figure-of-merit of bismuth telluride which is five layered (Te-Bi-Te-Bi-Te) crystal with hexagonal symmetry with six equivalent valleys, in the range 40–300 Å and observe that for 100 Å well width three sub-band model and for 200 Å well width six sub-band model are good approximation at room temperature. Further it is observed that optimum carrier density for 200 Å well width is and maximum of ZT shifts towards lower concentration; and discusses the acceptability of single band approximation.
Author: M P Singh
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,880
OpenAlex ID: W2790531479