Thermoelectric performance of p-type skutterudites YbxFe4−yPtySb12 (0.8 ≤ x ≤ 1, y = 1 and 0.5)

Thermoelectric performance of p-type skutterudites currently lags that of the corresponding n-type materials, and improvement of this important class of materials has become the focus of considerable research effort world-wide. Recent calculations find promising band structure features in p-type skutterudite materials of the type AFe3NiSb12 (A = Ca, Sr, or Ba), which could potentially lead to excellent thermoelectric properties. Recent work on the Yb-filled analogs of these formulations (YbFe3NiSb12) however, finds that the onset of intrinsic conduction at lower than expected temperatures deteriorates the performance above 500 K. This leads to performance in the temperature range of interest for automotive waste heat recovery applications. We, therefore, seek a way to increase the band gap in order to find a way to minimize the deleterious effects of intrinsic conduction on thermoelectric performance. Here, we present ab initio band structure calculations, the synthesis and thermoelectric properties of Yb...