A concept of nonequilibrium solar cell heat recovery solar cell

We present a concept of nonequilibrium solar cell, heat recovery solar cell (HERC cell), with its theoretical efficiency exceeding the detailed-balance limit. HERC cell uses an absorber hotter than electrodes, in terms of the lattice temperatures, and carrier-energy selecting layers in front of the electrodes. As being different from hot carrier solar cells, HERC cell does not require fast carrier extraction within the thermalization time and therefore the concept can be used to improve Si solar cells. Thermoelectric voltage produced by the temperature difference recovers the reduction due to the internal voltage drop in the hot absorber and improves the open-circuit voltage as a whole.