(Invited) Recent Advances on the Promising Thermoelectric Oxides Materials
Recently, the improved knowledge of the underlying physics of thermoelectric materials, together with advanced synthesis techniques, has led to the discovery of new material systems with ZT values higher than 2 at elevated temperatures [1-5]. However the generally complex and costly synthesis procedures, together with the expensive, toxic, and rare elements used, present serious impediments to large scale applications. In this context, work therefore continues to focus on the development of thermoelectric materials and processing methods that not only can exhibit high performance, but also possess the potential to be produced on a large scale.
In this context oxide materials appear as promising materials due to their wide range of electronic properties ranging from insulating to semiconducting and conducting . Their electronic properties can be engineered by changing their morphology, doping and stoichiometry. Based on this trend, the relationship between the stacking sequence and the thermoelectric properties of the Ba-Co-O system will be discussed. Indeed, the wide range of polytypic structures associated to this system offers a great opportunity for designing an “optimal” structure.
 J. P. Heremans, V. Jovovic, E. S. Toberer, A. Saramat, K. Kurosaki, A. Charoenphakdee, S. Yamanaka, G. J. Snyder, Science, 321 554–7 (2008).
 Y. Pei, A. Lalonde, S. Iwanaga, G. J. Snyder, Energy Environ. Sci., 4  2085-2089 (2011).
 Y. Pei, X. Shi, A. Lalonde, H. Wang, L. Chen, G. J. Snyder, Nature, 473  66–9 (2011).
.S. N. Girard, J. He, X. Zhou, D. Shoemaker, C. M. Jaworski, C. Uher, V. P. Dravid, J. P. Heremans, M. G. Kanatzidis, J. Am. Chem. Soc., 133  16588–16597 (2011).
 K. Biswas, J. He, I. D. Blum, C. Wu, T. P. Hogan, D. N. Seidman, V. P. Dravid, M. G. Kanatzidis, Nature, 490 414–418 (2012).
 W. E. Pickett, Rev Mod Phys, 61:433–512 (1989).