The cross-plane mobility, in the direction perpendicular to the planes of a superlattice, is critical for the computation of the figure of merit (ZT) in a thermoelectric device. The measurement of cross-plane mobilities in thermoelectric superlattice structures cannot be performed by conventional techniques such as the van der Pauw method. Therefore, alternative techniques must be used to obtain this important parameter. Magnetoresistance is the increase in material resistivity due to a lengthened path for charge carriers in a perpendicular magnetic field. The magnetoresistance is related to the magnetic field strength as ({mu}B)2 in the standard configuration, but the field dependence …
continued below
Publisher Info:
National Renewable Energy Lab., Golden, CO (United States)
Place of Publication:
Golden, Colorado
Provided By
UNT Libraries Government Documents Department
Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.
Descriptive information to help identify this article.
Follow the links below to find similar items on the Digital Library.
Description
The cross-plane mobility, in the direction perpendicular to the planes of a superlattice, is critical for the computation of the figure of merit (ZT) in a thermoelectric device. The measurement of cross-plane mobilities in thermoelectric superlattice structures cannot be performed by conventional techniques such as the van der Pauw method. Therefore, alternative techniques must be used to obtain this important parameter. Magnetoresistance is the increase in material resistivity due to a lengthened path for charge carriers in a perpendicular magnetic field. The magnetoresistance is related to the magnetic field strength as ({mu}B)2 in the standard configuration, but the field dependence is also influenced by device geometry. This work focuses on measuring superlattice samples of composition Bi2Te3/Sb2Te3 that are removed from their growth substrate and mounted on metal-coated substrates. This resulting mesa structure has a 100-mm-square contact metallization. Technical issues related to the sample preparation for the measurement are discussed. The magnetoresistance effect is expected to be small due to the anticipated low mobilities in Bi2Te3-based materials. Magnetoresistance studies with such superlattice thermo-elements were attempted using a dc magnetic field, but the sensitivity was insufficient. An ac magnetoresistance with lock-in detection can yield improved sensitivity.
This article is part of the following collection of related materials.
Office of Scientific & Technical Information Technical Reports
Reports, articles and other documents harvested from the Office of Scientific and Technical Information.
Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.
Johnston, S. W.; Ahrenkiel, R. K.; Young, D. & Venkatasubramanian, R.Magnetoresistance Technique for Determining Cross-Plane Mobility in Superlattice Devices,
article,
September 1, 1999;
Golden, Colorado.
(https://digital.library.unt.edu/ark:/67531/metadc620334/:
accessed April 19, 2024),
University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu;
crediting UNT Libraries Government Documents Department.