Microwave sintering of Ge-doped In2O3 thermoelectric ceramics processed by slip-casting

Nowadays, thermoelectric oxide materials are well studied for the realization of efficient thermoelectric devices, especially for high temperature applications due to their high chemical stability. Recently, different formulations of metal doped indium oxide ceramics with interesting thermoelectric properties have been reported. If the carrier concentration of these materials can be easily tuned to optimize the electrical and thermal properties, the study of the microstructure reveals porous materials and evidences some lacks in the densification process, especially using fine nanopowders. The improvement of the thermoelectric properties requires now the development of innovative forming and sintering processes for improving the sinterability and the density of the final products. For that purpose, slip-casting and fast sintering (microwave sintering) techniques have been combined for the synthesis of highly dense In2-xGexO3 ceramics. In this study, we report on the impact of the use of these different techniques on the sintering and the thermoelectric properties of these compounds.