Universal curve of optimum thermoelectric figures of merit for bulk and low-dimensional semiconductors

摘要

Analytical formulas for thermoelectric figure of merit and power factor arederived based on the one-band model. We find that there is a directrelationship between the optimum figures of merit and the optimum power factorsof semiconductors despite of the fact that the two quantities are generallygiven by different values of chemical potentials. By introducing adimensionless parameter consisting of optimum power factor and lattice thermalconductivity (without electronic thermal conductivity), it is possible to unifyoptimum figures of merit of both bulk and low-dimensional semiconductors into asingle universal curve that covers lots of materials with differentdimensionalities.