Electronic Transport of Bismuth telluride

The electronic transport properties vary significantly with alloy composition. Pisarenko plot fits of Seebeck versus Hall carrier concentration using a single valley effective mass model assuming potential deformation scattering find that the Seebeck effective mass, m∗S, decreases from 1.06 me for Bi2Te3 to 0.25 me for Bi2Se3. Similarly, the weighted mobility, μw, which sets the maximum achievable power factor, decreases monotonically from 590 to 170 cm2V-1 s-1 going from Bi2Te3 to Bi2Se3. This is likely due to a loss of Fermi surface complexity by a decrease in valley degeneracy and by a decrease in the conduction anisotropy of each valley. In the Bi2Te3-Sb2Te3 alloy system, a peak in the effective mass and an abrupt change in the band gap slope with composition are observed near Bi0.5Sb1.5Te3. This has been attributed to the crossing in energy with the composition of two Nv=6 valence bands. In the n-type alloy system, there is a peak in the band gap with alloy composition very near Bi2Te2Se and a peak in Seebeck effective mass of ~1.30 me near Bi2Te2.5Se0.5. As the compositions for the two peaks do not coincide, the transport behavior cannot be described by a simple crossing of two conduction bands, and a more detailed investigation is required. If you are looking for high quality, high purity, and cost-effective Bismuth Telluride, or if you require the latest price of Bismuth Telluride, please feel free to email contact mis-asia.

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