In this article, we review some of the ideas relevant to Peltier cooling at room temperatures and below. We identify challenges and directions for thermoelectric refrigeration. We also point out that measures other than ZT, should be used for active cooling cycle where heat is pumped from hot to cold. Finally, we review several strategies proposed in the past by our group and others to enhance the thermoelectric power factor.
"Enhancing thermoelectric power factor at low temperature", Proc. SPIE 10121, Optical and Electronic Cooling of Solids II, 101210M (17 February 2017); doi: 10.1117/12.2256249; https://doi.org/10.1117/12.2256249