An analytic study of the Wiedemann–Franz law and the thermoelectric figure of merit

Abstract

Advances in optimizing thermoelectric material efficiency have seen parallel activities in theoretical and computational studies. In the current work, we calculate the exact Fermi-Dirac integrals to enable the generalization of the Wiedemann-Franz law (WF) in order to enhance the dimensionless thermoelectric figure of merit ZT 2 a s k = . This is done by optimizing the Seebeck coefficient α, the electrical conductivity σ, and the thermal conductivity κ in terms of the Lambert W, and the generalized Lambert W functions (offset log). In the calculation of the thermal conductivity κ, we include both electronic and phononic contributions. The solutions provide insight into the relevant parameter space including the physical significance of complex solutions and their dependance on the scattering parameter r and the reduced chemical potential μ * .

SiH monolayer : A promising two‐dimensional thermoelectric material

“…Electronic thermal conductivity decreases with increase in temperature due to the scattering of electrons. The variation of and k e with temperature has the same behavior as they are related by Wiedemann‐Franz law k e = 𝐿𝜎𝑇 54 . The peak value of k e is found to be 42.18 (24.04) W/mK for n (p) type doping which is much lower than other SiX monolayers due to the large bandgap of SiH monolayer.…”

“…The variation of σ and k e with temperature has the same behavior as they are related by Wiedemann-Franz law k e = LσT. 54 The peak value of k e is found to be 42.18 (24.04) W/mK for n (p) type doping which is much lower than other SiX monolayers due to the large bandgap of SiH monolayer. The power factor (PF), defined as PF ꞊ S 2 σ, indicates that the electronic transport behavior of material is calculated at different temperatures as shown in Figure 4(D).…”

Janus β-PdXY (X/Y = S, Se, Te) materials with high anisotropic thermoelectric performance

“…Furthermore, the electronic thermal conductivity is defined as K e = LσT by the Wiedemann–Franz law, 88 where the Lorenz number ( L ) is useful in a variety of scenarios, such as designing thermoelectric materials and determining the lattice thermal conductivity experimentally. The L of the Wiedemann–Franz law is known to deviate from expected values due to many exotic scenarios such as multi-band and bipolar effects in semiconductors.…”

Hydrogenation and oxidation enhances the thermoelectric performance of Si2BN monolayer

“…Thermoelectric materials can generate power using the Seebeck effect or refrigerate using the Peltier effect. They are capable of converting heat flow directly into electrical energy or vice-versa [2][3]. Thermoelectric materials can be employed in aerospace applications, solar energy, cooling-thermal management, waste heat recovery, and electronic techniques due to the characters of scalability, lightweight, no moving parts, no pollution, and long operating life [4][5][6].…”

“…Moreover, the presence of Si atoms in the monolayer of Si 2 BN will make the surface more reactive. Therefore, it is a very interesting material candidate for hydrogen storage [2][3][4][5][6][7][8]. In all of these materials, such as 2D graphene i.e.…”