Charge carrier

Electron mobility

Semiconductor

Seebeck coefficient

Analytical Chemistry (journal)

Electrical engineering

Physics

Engineering

Hall effect

Chemistry

Materials science

Thermoelectric materials

Condensed matter physics

Chromatography

Optoelectronics

Thermoelectric effect

Electrical resistivity and conductivity

Thermodynamics

Advanced Materials

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 cm2 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 cm2 V-1 s-1, μ w = 331 c m 2 V 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 / e 1 + exp [ 5 ( | S | k B / e − 1 ) ] ] Here, μw 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 kB/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.

Weighted Mobility