From oxides to selenides and sulfides: The richness of the CdI2 type crystallographic structure for thermoelectric properties (pages 69–81)
S. Hébert, W. Kobayashi, H. Muguerra, Y. Bréard, N. Raghavendra, F. Gascoin, E. Guilmeau and A. Maignan
Version of Record online: 18 DEC 2012 | DOI: 10.1002/pssa.201228505
The CdI2 type crystallographic structure is a very rich family in which oxides and non-oxide materials can be synthesized. For oxides, NaxCoO2 has already been found to be a promising p-type thermoelectric material. The aim of this Feature Article is first to analyze the thermoelectric properties of misfit cobalt oxides, showing the relationship between this layered structure which stabilizes Co3+ and Co4+ in low spin states, and transport properties. By changing the separating block layer, or by modifying oxides into selenides or sulfides, it is possible to strongly modify the transport properties. The second part of this Feature Article reports the interesting thermoelectric properties of sulfides and selenides, with ZT up to 0.5 at 800 K, and shows the differences between these properties and that of oxides.