Some peculiarities of development of efficient thermoelectrics based on silicon compounds

Many silicon compounds which can be used as thermoelectrics have complex structure of conduction or valence band. If it is possible to change energy gaps or effective masses in some energy band it can be either useful or harmful for the increase of thermoelectric figure of merit. In the present work some features of energy spectrum of current carriers of Mg₂Si and Mg₂Sn compounds and their solid solutions are discussed. Thermoelectric properties of these materials and their relations with the band structure are discussed. The optimization of electron energy spectrum in the solid solutions of Mg ₂Si-Mg₂Sn system allowed to develop very efficient thermoelectrics with ZT_max > 1.1