Thermion/Photon and the Work function

[GibbsHelmholtz]

I see, we have an Electrostatic guy in here.  Full house ya say?

The circuit is now evolves into DC current.  Two dissimilar conductor A and B is connected.  A third conductor C is in alternate contact between A and B.  Direct current is observed.  I would say the circuit affinity Vab = Va - Vb .  One can imagine an energetic conductive particle in place of conductor C.  This form of generation is not chemical.

[exnihiloest]

Why do you think that Vab ≠ 0?

[GibbsHelmholtz]

If A and B in contact, one would pull more electron from the other when separate.

[exnihiloest]

@gh

Ok, I understand one the misunderstanding. By "two dissimilar conductors A and B", I should have interpreted "two dissimilar metals".
But it's still not clear. When you say "direct current is observed", which is the circuit where the current is flowing?