Nano Archive

Large enhancement of the thermoelectric figure of merit in a ridged quantum well

Tavkhelidze, A. (2010) Large enhancement of the thermoelectric figure of merit in a ridged quantum well. Nano Studies, 1 . pp. 145-154. ISSN 1987-8826

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Abstract

Recently, new quantum features have been observed and studied in the area of ridged quantum wells (RQWs). Periodic ridges on the surface of the quantum well layer impose additional boundary conditions on electron wave function and reduce the quantum state density. As a result, the chemical potential of RQW increases and becomes ridge height dependent. Here, we propose a system composed of RQW and an additional layer on the top of the ridges forming periodic series of p^+–n^+ junctions (or metal–n^+ junctions). In such systems, charge depletion region develops inside the ridges and effective ridge height reduces, becoming a rather strong function of temperature T. Consequently, T-dependence of chemical potential magnifies and Seebeck coefficient S increases. We investigate S in the system of semiconductor RQW having abrupt p^+–n^+ junctions or metal–n^+ junctions on the top of the ridges. Analysis made on the basis of Boltzmann transport equations shows dramatic increase in S for both the cases. At the same time, other transport coefficients remain unaffected by the junctions. Calculations show one order of magnitude increase in thermoelectric figure of merit ZT relative to the bulk material.

Item Type:Article
Subjects:Physical Science > Quantum phenomena
Divisions:Faculty of Engineering, Science and Mathematics > School of Physics
ID Code:11746
Deposited By:Professor Levan Chkhartishvili
Deposited On:20 Jan 2012 16:55
Last Modified:20 Jan 2012 16:55

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