Effective Mass from Seebeck Coefficient

Abstract

Engineering semiconductor devices requires an understanding of the effective mass of electrons and holes. Effective masses have historically been determined in metals at cryogenic temperatures estimated using measurements of the electronic specific heat. Instead, by combining measurements of the Seebeck and Hall effects, a density of states effective mass can be determined in doped semiconductors at room temperature and above. Here, a simple method to calculate the electron effective mass using the Seebeck coefficient and an estimate of the free electron or hole concentration, such as that determined from the Hall effect, is introduced mS∗me=0.924(300KT)(nH1020cm−3)2/3[3(exp[|S|kB/e−2]−0.17)2/31+exp[−5(|S|kB/e−kB/e|S|)]+|S|kB/e1+exp[5(|S|kB/e−kB/e|S|)]] here mnormalS∗ is the Seebeck effective mass, nH is the charge carrier concentration measured by the Hall effect (nH = 1/eRH, RH is Hall resistance) in 1020 cm−3, T is the absolute temperature in K, S is the Seebeck coefficient, and kB/e = 86.3 μV K−1. This estimate of the effective mass can aid the understanding and engineering of the electronic structure as it is largely independent of scattering and the effects of microstructure (grain boundary resistance). It is particularly helpful in characterizing thermoelectric materials.

Prediction and realisation of high mobility and degenerate p-type conductivity in CaCuP thin films

“…S11 †) we can estimate the effective mass of CaCuP using previously developed theory. 56 This analysis yields an effective mass of 0.44 m e , in excellent agreement with the direction-averaged heavy hole effective mass (0.43 m e ) obtained from DFT calculations. 24 The hole concentration of CaCuP lms rises very slowly with temperature (Fig.…”

Approach to Determine the Density‐of‐States Effective Mass with Carrier Concentration‐Dependent Seebeck Coefficient

“…For this reason, the m d * in Equations ( 2) and ( 3) is also referred to as the Seebeck effective mass (m S *). [20,21] It is to be noted that the m d * is different from another effective mass (m*) defined using the second derivative of E(k), where E and k are the energy, and the wavevector, respectively. While the m d * is independent of E, the m* changes with E. [19] Last, there is the conductivity effective mass (m c *) which represents the band mass close to the Fermi energy.…”

Abnormal Seebeck Effect in Vertically Stacked 2D/2D PtSe2/PtSe2 Homostructure

“…[32][33] If the momentum transfer of the carriers was happened by the out-ofplane temperature difference, we can expect some quantitative changes in the PtSe 2 /PtSe 2 homostructure. To confirm this assumption, we calculated the Seebeck effective mass (m * s )of PtSe 2 films using a model presented by Snyder [34] because the magnitude is proportional to the its effective mass according to the Mott relation. [35] The Seebeck effective mass of PtSe 2 films is determined by the following equation [34] m * s m e = 0.924…”