Enhanced thermoelectric properties of Te-doped and In, Ba double-filled CoSb3 composites by high pressure technology

In this paper, Te-doped multifilled n-type skutterudite compounds were prepared by high pressure and high temperature (HPHT) method and characterized by X-ray and SEM, which showed that InxBa0.2-xCo4Sb11.5Te0.5 samples with fine grain size can be prepared by HPHT rapidly. Both thermal transport properties and electrical transport properties have been characterized in the temperature range of 363-765 K. The combination of (In, Ba) double-filled and Te-doped is more effective than simple Te-doped or the combination of In-filled and Te-doped in reducing lattice thermal conductivity. Finally, the figure of merit value (ZT) of In0.15Ba0.05Co4Sb11.5Te0.5 reached 1.11 at 765 K. This showed that the ZT values of samples can likely be improved through combining multiple filling atoms and doping atoms to broaden the range of resonant phonon scattering.