The origin of the Seebeck effect, in which a temperature difference produces a voltage, is that charged particles (electrons or holes) with large kinetic energy on the hot side tend to diffuse toward the cold side. In ①, you watch this in an animation (the size of the thermal fluctuations, the charge imbalance, and the current that flows when the circuit is connected). In ②, you calculate S, σ and κ as functions of carrier concentration with the single parabolic band model and confirm that the figure of merit ZT forms a peak (its top lies near 1019–1020 cm−3). ③–⑥ cover the quality factor B, which sets the height of the peak; PGEC, which lowers the lattice thermal conductivity; conversion efficiency and cooling; and where real materials are used.
Mochizuki Research Group, Tokyo University of Science / ① is a schematic with 2D classical particles, and the voltage is scaled by |S|. ②, ③ and ④ are educational calculations of the single parabolic band model (acoustic-phonon scattering), computed on the spot by the JavaScript of this page; the presets are order-of-magnitude guides (they do not reproduce measured ZT values). Approximations, derivations and sources are given in the explanation page, Appendix A (in Japanese).