  We consider the thermoelectric properties of the mixed-dimensional quantum
electrodynamics of the relativistic Dirac fermion and Wilson-Fisher boson.
These models are self-dual, and can form non-trivial many-body phases depending
on the values of chemical potential, background magnetic field and the
electromagnetic fine-structure constant. Using particle-vortex duality, we
derive a variety of thermoelectric relations for strongly-interacting phases
with classic paradigms such as the Wiedemann-Franz law and the Mott's relation
in the dual weakly interacting regimes. Besides, at the self-dual point, for
the fermionic theory we find the ratio of thermal conductivity of electrical
conductivity depends on the determinant of the Seebeck tensor and the
phenomenological parameter Hall angle $\theta_H$. As for the bosonic theory,
the dual fermion description explains how its Seebeck tensor varies depending
on the dynamic regime characterized by $\theta_H$.
