Research progress of p-type Fe-based skutterudite thermoelectric materials

Filled skutterudite is currently one of the most promising intermediate-temperature thermoelectric (TE) materials, having good thermoelectric transport performance and excellent mechanical properties. For the preparation of high-efficiency filled skutterudite TE devices, it is important to have p- and n-type filled skutterudite TE materials with matching performance. However, the current TE properties of p-type Fe-based filled skutterudite materials are worse than n-type filled skutterudite materials. Therefore, how to obtain high-performance p-type Fe-based filled skutterudite materials is the key to preparation of high-efficiency skutterudite-based TE devices. This review summarizes some methods for optimizing the thermal transport performance of p-type filled skutterudite materials at the atomic-molecular and nano-mesoscopic scale that have been used in recent years. These methods include doping, multi-atom filling, and use of low-dimensional structure and of nanocomposite. In addition, the synergistic optimization methods of the electrical and thermal transport parameters and advanced preparation technologies of p-type filled skutterudite materials in recent years are also briefly summarized. These optimizational methods and advanced preparation technologies can significantly improve the TE properties of p-type Fe-based filled skutterudite materials.