abstract
Currently much worldwide research is focused on clean and sustainable energy sources that can respond to the rising energy demands of the world. Thermoelectric (TE) harvesting of unused heat in automotive exhaustion, industrial processes and home heating will increase the efficiency of energy use, while simultaneously reducing the CO2 emissions. Although a number of high TE performance materials, such as Te-based, Se-based and intermetallic compounds, have been developed so far, most of them suffer from toxicity, mineral scarcity and high cost, which are problems for universal application. Moreover, they are limited in their ability to harvest electricity from solar, automotive and industrial waste heat, due to their decomposition and volatilisation at elevated temperatures. As a result, new, nontoxic, more stable, naturally abundant, light-weight and low-cost materials based on oxides have to be developed, despite the fact that oxides are of low carrier mobility and high thermal conductivity in general. Thus, p-type oxides based on cobaltates have been found to be very promising, especially in high temperature ranges. To date, n-type oxides with equivalent TE performance have yet to be discovered to produce effective p-n TE modules. Here we will summarise the most relevant studies devoted to the TE behaviour of n-type SrTiO3-based ceramics. Doping, nonstoichiometry and other important parameters to enhance the TE performance will be discussed. Particle size of Nb-doped SrTiO3 powders, together with sintering conditions, will also be shown as key parameters able to increase the TE figure of merit, either by microstructure engineering or by densification.
authors
Tkach, A; Resende, J; Diaz-Chao, P; Guilmeau, E; Costa, ME; Vilarinho, PM
our authors
Maria Elisabete Jorge Vieira Costa
Collaborator
Oleksandr Tkach
Assistant Researcher
Paula Maria Lousada Silveirinha Vilarinho
Vice DirectorOther
