In search of efficient n-type skutterudite thermoelectrics

Filled skutterudites continue to draw attention as prospective novel thermoelectric materials for power generation applications in the range of temperatures around 700 K-800 K. High ZT values established on the p-type forms of R/sub y/Co/sub x/Fe/sub 4-x/Sb/sub 12/ (R standing for a rare earth element) some time ago are now being approached with the n-type forms of filled skutterudites. I review the work done during the past two years in developing various n-type filled skutterudites with the dimensionless figure of merit in excess of unity.