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Weighted Mobility
Author(s) -
Snyder G. Jeffrey,
Snyder Alemayouh H.,
Wood Maxwell,
Gurunathan Ramya,
Snyder Berhanu H.,
Niu Changning
Publication year - 2020
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.202001537
Subject(s) - seebeck coefficient , electrical resistivity and conductivity , materials science , electron mobility , semiconductor , thermoelectric effect , charge carrier , hall effect , thermoelectric materials , condensed matter physics , electrical mobility , optoelectronics , thermodynamics , thermal conductivity , electrical engineering , electric field , physics , composite material , engineering , quantum mechanics
Engineering semiconductor devices requires an understanding of charge carrier mobility. Typically, mobilities are estimated using Hall effect and electrical resistivity meausrements, which are are routinely performed at room temperature and below, in materials with mobilities greater than 1 cm 2 V ‐1 s ‐1 . With the availability of combined Seebeck coefficient and electrical resistivity measurement systems, it is now easy to measure the weighted mobility (electron mobility weighted by the density of electronic states). A simple method to calculate the weighted mobility from Seebeck coefficient and electrical resistivity measurements is introduced, which gives good results at room temperature and above, and for mobilities as low as 10 −3 cm 2 V ‐1 s ‐1 ,μ w = 331 c m 2V s(m Ω c m ρ ) ( T 300 K)− 3 / 2[e x p [| S |k B / e − 2 ]1 + exp [ − 5 (| S |k B / e − 1 )]+3 π 2| S |k B / e1 + exp [ 5 (| S |k B / e − 1 )]]Here, μ w is the weighted mobility, ρ is the electrical resistivity measured in mΩ cm, T is the absolute temperature in K, S is the Seebeck coefficient, and k B /e = 86.3 µV K –1 . Weighted mobility analysis can elucidate the electronic structure and scattering mechanisms in materials and is particularly helpful in understanding and optimizing thermoelectric systems.