NOVELTY - A surface-plasmon-coupled thermoelectric apparatus (10) comprises first surface plasmon substrate (12), electrodes (16), and thermoelectric substrate (14) electrically coupled to the electrodes. The substrates are electrically isolated from each other. A first face of the thermoelectric substrate opposes a first face of the surface plasmon substrate to define phonon insulating gap (18).    USE - For use as thermoelectric energy conversion devices.    ADVANTAGE - The invention has increased efficiency. It has gap that is easier to manufacture and maintain than the angstrom-scale gap needed in devices relying on quantum mechanical tunneling of the electrons.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (a) transferring thermal energy across a phonon insulating gap comprising creating first surface plasmon polariton at first surface plasmon substrate, creating non-equilibrium state between the electron temperature and phonon temperature at the first face of thermoelectric substrate, and coupling the first surface plasmon polariton with electrons in the thermoelectric substrate across the phonon insulating gap thus transferring thermal energy between thermal reservoirs across the phonon insulating gap;    (b) surface plasmon coupled refrigeration and generator comprising the above mentioned apparatus;    (c) refrigeration comprising applying electrical current to create a lower electron temperature compared to the phonon temperature at first face of the thermoelectric substrate, coupling first surface plasmon polariton at first surface plasmon substrate across a phonon insulating gap with second surface plasmon polariton at the second surface plasmon substrate, and refrigerating first thermal reservoir contacting the first plasmon substrate by directing thermal energy through the coupled surface plasmon polaritons to the electrons in the thermoelectric substrate and then to the second thermal reservoir contacting the thermoelectric substrate; and    (d) generating electrical current comprising operating first thermal reservoir at higher temperature than a second thermal reservoir, coupling first surface plasmon polariton at the first surface plasmon substrate to the second surface plasmon polariton at the second surface plasmon substrate, thus the thermal energy is transferred across the phonon insulating gap, and applying load circuit to the thermoelectric substrate, thus the difference between the electron temperature at the first face of the thermoelectric substrate and at the second thermal reservoir generates electric current in load circuit    DESCRIPTION OF DRAWING(S) - The figure shows a surface-plasmon-coupled thermoelectric apparatus.    First surface plasmon substrate (12)    Thermoelectric substrate (14)    Electrodes (16)    Phonon insulating gap (18)