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dc.contributor.authorPorter, Claire E.
dc.contributor.authorQu, Jiaxing
dc.contributor.authorCiesielski, Kamil
dc.contributor.authorErtekin, Elif
dc.contributor.authorToberer, Eric
dc.date2023-04
dc.date.accessioned2023-05-23T17:21:14Z
dc.date.available2023-05-23T17:21:14Z
dc.identifier.urihttps://hdl.handle.net/11124/176965
dc.identifier.urihttps://doi.org/10.25676/11124/176965
dc.description.abstractHigh charge carrier mobility in semiconductor materials is desirable across a broad range of fields ranging from light-emitting devices to thermoelectrics. Electronic mobility is driven by both the intrinsic electronic band structure of the material as well as the energy dependent electron scattering mechanisms. Semiconductors with excellent mobility span a large chemical space: transparent conductor CdO, topological insulator HgTe, and Zintl compound KAlSb4. Therefore, engineering high mobility from chemistry alone is difficult if not impossible. Relating chemistry and synthetic processing to their impact on mobility is highly desirable, but experimentally difficult. Adding a fourth thermomagnetic measurement, the Nernst coefficient, to the traditional thermoelectric transport measurement suite (resistivity, Hall coefficient, Seebeck), allows the experimentalist to derive a carrier lifetime/scattering parameter as a function of temperature. We design a custom apparatus to measure the Nernst effect and perform initial model measurements to address the question of what scattering mechanisms limit the mobility of several potential thermoelectric materials. In our design, we test different sample and sample holder geometries to optimize reproducibility. For the model materials we measure the Nernst signal at low magnetic field (µB < 1) in addition to traditional Hall coefficient, Seebeck, and resistivity. We employ the method of four coefficients to determine four electronic parameters: µ, n, m*DOS, and λ (scattering factor). By utilizing the method of four coefficients, we can decouple effects from electronic band structure from energy-dependent scattering effects, and therefore design optimal thermoelectric materials and validate the scattering predictions from computational methods.
dc.format.mediumpresentation slides
dc.languageEnglish
dc.language.isoeng
dc.publisherColorado School of Mines. Arthur Lakes Library
dc.relation.ispartof2023 Graduate Research And Discovery Symposium (GRADS) posters and presentations
dc.rightsCopyright of the original work is retained by the author.
dc.titleUnderstanding charge carrier mobility in Hg₂GeTe₄
dc.typeText
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