The polylogarithm and the Lambert W functions in thermoelectrics
- Citation data:
Canadian Journal of Physics, ISSN: 0008-4204, Vol: 89, Issue: 11, Page: 1171-1178
- Publication Year:
- Physics and Astronomy; Polylogarithms; Lambert W Functions; Thermoelectrics; Riemann Zeta Functions; Reduced Chemical Potential; Astrophysics and Astronomy; Physics
In this work, we determine the conditions for the extremum of the figure of merit, θ, in a degenerate semiconductor for thermoelectric (TE) applications. We study the variation of the function θ with respect to the reduced chemical potential μ* using relations involving polylogarithms of both integral and nonintegral orders. We present the relevant equations for the thermopower, thermal, and electrical conductivities that result in optimizing θ and obtaining the extremum equations. We discuss the different cases that arise for various values of r, which depends on the type of carrier scattering mechanism present in the semiconductor. We also present the important extremum conditions for θ obtained by extremizing the TE power factor and the thermal conductivity separately. In this case, simple functional equations, which lead to solutions in terms of the Lambert W function, result. We also present some solutions for the zeros of the polylogarithms. Our analysis allows for the possibility of considering the reduced chemical potential and the index r of the polylogarithm as complex variables. © 2011 Published by NRC Research Press.