A detailed, and hopefully definitive explanation.

Let’s return to the Seebeck thermionic phenomenon, namely, the appearance of a potential difference on a thermocouple, one junction of which is heated and the other is cooled. Why does,a very small, microvolt per degree ,arise, but still a certain potential difference (voltage)?

The explanation in the “Seebeck and Peltier Effects” note is simple and straightforward:

The external electronic orbits of metal atoms OVERLAP, resulting in a population of free electrons that can move freely to any part of the metal.

Which they do, moving chaotically at speeds of about a thousand kilometers per second and having a CONSTANT AND TEMPERATURE-INDEPENDENT, so-called ZERO ENERGY of several electron volts.

When one junction heats up and the other cools down, on a hot junction, the outer orbits of atoms change their configuration, increasing in size and shifting relative to each other – an increment in the thermal potential energy of the atoms. At the same time, the orbits increase and overlap, and this “frees up” additional electrons. That is, heating always increases the concentration of free electrons in the metal (and, of course, in semiconductors). Moreover, their mobility and chaotic velocities REMAIN UNCHANGED, ONLY THE CONCENTRATION of free electrons in the heated area increases.

(Actually, the junction of two different metals PLAYS almost NO ROLE in the occurrence of a thermoelectric potential difference, it is only a kind of valve that passes accumulated electrons in one direction, and not immediately in both directions along a metal conductor. A potential barrier is a contact potential difference, a double electrical layer, and a Volt–Galvanic voltage.)

Due to the increase in the concentration of free electrons, their mutual Coulomb repulsion also increases, and therefore the electron cloud begins to gradually diffuse towards a LOWER “electrostatic pressure”, namely, towards a COLD junction. An imbalance of the electron density occurs, which generates a thermoelectric potential difference and thus a current.

We repeat the explanation of the Seebeck effect in such detail because, without understanding it, we will not be able to correctly explain the Peltier effect that is opposite to it!

The main role in both effects, contrary to my previous attempts to find an explanation, is played by only one factor – the LOCAL CONCENTRATION OF FREE ELECTRONS.

Now let’s make a small and NOT lyrical, but necessary digression. Let’s imagine a certain metal sample consisting entirely of “ideal atoms”, that is, atoms whose configuration of electronic orbits is not distorted by anything, there is no deformation. This is what is observed in the substance at temperatures close to Absolute zero – 273 degrees Celsius. If a given metal sample is in a state of superconductivity, this absolute “rest” of its atoms is (almost, except so called “zero vibrations”) not disturbed. All or the vast majority of free electrons have combined into Cooper pairs with ZERO SPIN and, therefore, zero magnetic moment, and their spin fields DO NOT DISTORT the ideal orbits of atoms at ALL.

Harmonious peaceful coexistence of two opposites – two systems of different particles – ions in the nodes of the crystal lattice and an electron gas (or liquid) in the space between the ions.

The first law of dialectics:

The law of unity and struggle of opposites:

Unity is relative.

The struggle is absolute.

And what happens in the same piece of metal at room temperature. Free electrons with a concentration of 6.5 x 10 to the twenty-second power in one cubic centimeter scurry past atoms at terrifying speeds and with their spin, chaotically directed magnetic fields all the time distort these orbits and disrupt the “natural ideal harmony”, DEFORMING THEM.!!!

“Ideal atoms” are very COLD atoms, “degenerate atoms” with deformed orbits are already more or less HEATED!

It turns out, and we return to the main topic again, that the higher the concentration of free electrons, the greater the “orbital disorder”, the more deformed orbits they create with their chaotic movement. And, the lower the local concentration of free electrons, the closer the atoms in this place are to the state of ideal atoms. Because they are less “disturbed”!

What happens when a current occurs in a conductor?

The entire cloud of free electrons, which are randomly rushing at high speeds, begins to drift in an orderly and extremely slow manner along a conductor, to the ends of which a potential difference is applied, and an electric field is created between its ends. But this is not just the movement of a cloud, the electron spins and their magnetic moments are rotated by the magnetic field of the current, like compass needles into some kind of coaxial rings, and THUS they begin to strongly adhere to the magnetic fields of atomic orbits, deforming them so that potential energy of deformation accumulates in them – HEAT!

Now, let’s imagine that we have combined two different metals with DIFFERENT concentrations of free electrons. What will the electric current do NOW?

Since the current is the same in any part of the circuit, this means that in one metal the CONCENTRATION of ELECTRONS WILL INCREASE (compared to the “natural” one), and in another metal it will DECREASE! We’ve just figured out WHAT this means for atomic orbits. Where the concentration is lower, there is less deformation of the orbits, the atoms become more “ideal” and COLDER, and where the concentration of free electrons brought by the current increases, the degree of deformation of the orbits increases, that is, HEATING!

Of course, even where the concentration decreases, there will still be some heating of the substance by current, but the process of COOLING to a certain amount of current competing with it will PREVAIL!

Why is this effect much greater on semiconductors than on ordinary metals and conductors?

Because, and this is exactly what makes semiconductors differ SIGNIFICANTLY from ordinary conductors, their concentration of free charge carriers, electrons and holes is VERY STRONGLY related to temperature and varies many times more than that of ordinary metals!

So we have come to an explanation of both Seebeck and Peltier effects from the standpoint of the Configurational Theory of Electronic Orbits and the concept of an “ideal atom”!

Faciant meliora potentes

If I’m wrong, let my seniors correct me.

23 XI 2025