Thermoelectricity, History, Renaissance, Recent Advances and Challenges

Energy is one of the several grand challenges facing the 21st century society. The current worldwide production of power is ~18 TW and is expected to grow to more than ~30 TW by 2050. Against this huge demand of power, known supply of fossil fuel (oil and gas) is rapidly shrinking and recovering fuels from new sources are becoming increasingly dangerous and costly. Thus there is a tremendous pressure to both increase the use of renewable sources of energy and to increase the efficiency of current power production. In the latter context thermoelectricity can play an important role in waste-heat recovery and power generation. In this lecture, I will first talk briefly about the history of thermoelectrics, its classical period and renaissance it went through before 1970. I will then discuss new and not so new ideas like quantum confinement, electron crystal phonon glass, nanostructuring, hierarchical structures, energy filtering etc. and how they have impacted the field of thermoelectrics during the last several decades to achieve higher efficiency. I will then end with some of the challenges facing this field and attempts to overcome them.