Since thermoelectrics is an energy-conversion technology from heat flow to electrical flow, or vice versa, it is essentially a non-equilibrium phenomenon in the sense that energy and particle flows are involved. We have recently focused on this feature in order to overcome theoretical predictions of the upper limit of the conversion efficiency in thermal equilibrium conditions. One trial is the thermoelectric phenomena in the range of non-ohmic conduction. The second approach is the thermoelectric phenomena shown by the photo-doped carriers.
Terasaki, I., Okazaki, R., & Ohta, H. (2016). Search for non-equilibrium thermoelectrics. Scripta Materialia, 111, 23–28. https://doi.org/10.1016/j.scriptamat.2015.04.033