Effect of Ag+ doping and Ag addition on the thermoelectric properties of KSr2Nb5O15

The electron and phonon thermal transport behavior of Ag+ doped KSr2Nb5O15 were discussed by using the first-principles calculations. The band gap was reduced after Ag+ doping, and the electrons near the Fermi level had stronger transition capability, which effectively increased the carrier concentration and electrical conductivity and reduced the thermal conductivity, thereby improving the ZT of the doped KSr2Nb5O15 from 0.6298 to 0.7214 (1200 K) under ideal conditions. In addition, the solid-state reaction method was used to prepare Ag nanoparticle added KSr2Nb5O15 samples, and their thermoelectric performance was tested. The experimental results and the calculated results showed a good consistent trend in which Ag improved the thermoelectric properties of KSr2Nb5O15. When the amount of addition of nanosized Ag was 20 wt%, the power factor and ZT of the material were the highest at 1073 K, which were 0.228 mW/(K-2 center dot m) and 0.1090, respectively. This research shows how to improve the thermoelectric performance of KSr2Nb5O15 ceramics and broaden their temperature range for application.

Automated summary

The electron and phonon thermal transport behavior of Ag+ doped KSr2Nb5O15 were studied, and it was found that Ag+ doping effectively increased the carrier concentration and electrical conductivity, reduced the thermal conductivity, and improved the thermoelectric performance. Experimental and calculated results showed that Ag improved the thermoelectric properties of KSr2Nb5O15. The addition of 20 wt% nanosized Ag resulted in the highest power factor and ZT at 1073 K.