Structural optimization for thermoelectric properties in Cu-Bi-S pavonite compounds

We report the enhancement of thermoelectric properties in the complex structured Cu-Bi-S pavonite compounds by optimizing the structural configuration through tuning the Bi-site occupancy, and substitutional doping at interstitial Cu sites by Zn. We verify that electronic transport properties depend on the structural deformation by the Bi site occupancy. Furthermore, we demonstrate that the modification of interstitial site ions enables selective control of thermal conductivity and intrinsically low thermal conductivity can be further suppressed by structural optimization without deteriorating electronic transport properties. We propose that understanding of crystal structure as a basic strategy permits the optimization of thermoelectric properties in the complex structures.