  A caloritronic device setup is proposed that harnesses the intrinsic
spin-valley locking of two-dimensional honeycomb lattices with graphene-like
valleys, for instance, silicene and stanene. Combining first-principles and
analytic calculations, we quantitatively show that when sheets of such
materials are placed on a ferromagnetic substrate and held between two contacts
at different temperatures, an interplay between the electron degrees-of-freedom
of charge, spin, and valley arises. A manifestation of this interplay are
finite charge, spin, and valley currents. Uniaxial strain that adjusts the
buckling height in silicene-type of lattices, in conjunction with an applied
electric field, is shown to further modulate the aforementioned currents. We
link these calculations to a Seebeck-like thermopower generator and obtain
expressions (and means to optimize them) for two spin-valley polarized
performance metrics--the thermodynamic efficiency and thermoelectric figure of
merit. A closing summary outlines possible enhancements to presented results
through the inherent topological order and substrate-induced external Rashba
spin-orbit coupling that exists in silicene-type materials.
