海歸學者發起的公益學術平臺
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交流學術, 偶爾風月
電子在固體內的環境相當複雜, 但其在原子晶格內仍可視為自由移動。
該文近期發表於npj Computational Materials 3: 7 (2017), 標題與摘要如下, 論文PDF文末點擊閱讀原文可以獲取。
Effective mass and Fermi surfacecomplexity factor from ab initio band structure calculations
Zachary M Gibbs,Francesco Ricci, Guodong Li, Hong Zhu, Kristin Persson, GerbrandCeder, GeoffroyHautier, AnubhavJain & G.Jeffrey Snyder
The effective mass is a convenientdescriptor of the electronic band structure used to characterize the density ofstates and electron transport based on a free electron model. While effectivemass is an excellent first-order descriptor in real systems, the exact valuecan have several definitions, each of which describe a different aspect ofelectron transport. Here we use Boltzmann transport calculations applied to abinitio band structures to extract a density-of-states effective mass from theSeebeck Coefficient and an inertial mass from the electrical conductivity tocharacterize the band structure irrespective of the exact scattering mechanism.We identify a Fermi Surface ComplexityFactor: Nv * K * from the ratio of these two masses,which in simple cases depends on the number of Fermi surfacepockets ( N v * ) and their anisotropy K*,both of which are beneficial to high thermoelectric performance as exemplifiedby the high values found in PbTe. The Fermi Surface Complexity factor can beused in high-throughput search of promising thermoelectric materials.
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