Title :
High figure of merit ZT in PbTe and Bi2Te3 based superlattice structures by thermal conductivity reduction
Author :
Lambrecht, A. ; Beyer, H. ; Nurnus, J. ; Künzel, C. ; Böttner, H.
Author_Institution :
Fraunhofer Inst. Physikalische Messtechnik, Freiburg, Germany
Abstract :
In superlattice (SL) structures an enhancement of the thermoelectric figure of merit ZT compared to homogeneous materials can be achieved by reduction of the thermal conductivity λ. In this context thermoelectric properties of PbTe/ PbSexTe1-x -SL´s, and PbTe(BaF2) doping superlattices (SL), and of Bi2(SexTe1-x)3/Bi2 (SeyTe1-y)3-SL structures are presented. All samples were grown on BaF2(111)-substrates by molecular beam epitaxy (MBE). A significant reduction of the in-plane thermal conductivity λ compared to corresponding bulk materials was observed. As the power factors are only slightly reduced, a net increase of the figure of merit ZT can be calculated. The temperature dependence of ZT is discussed
Keywords :
IV-VI semiconductors; barium compounds; bismuth compounds; lead compounds; molecular beam epitaxial growth; semiconductor growth; semiconductor materials; semiconductor superlattices; thermal conductivity; thermoelectricity; BaF2(111)-substrates; Bi2(SexTe1-x)3-Bi 2(SeyTe1-y)3; Bi2(SexTe1-x)3/Bi 2(SeyTe1-y)3; Bi2Te3; PbTe; PbTe(BaF2) doping superlattices; PbTe-PbSexTe1-x; PbTe/PbSexTe1-x; PbTe:BaF2; high figure of merit; in-plane thermal conductivity; molecular beam epitaxy; power factors; superlattice structures; thermal conductivity reduction; thermoelectric figure of merit; Bismuth; Conducting materials; Doping; Molecular beam epitaxial growth; Reactive power; Superlattices; Tellurium; Temperature dependence; Thermal conductivity; Thermoelectricity;
Conference_Titel :
Thermoelectrics, 2001. Proceedings ICT 2001. XX International Conference on
Conference_Location :
Beijing
Print_ISBN :
0-7803-7205-0
DOI :
10.1109/ICT.2001.979900
