New insights on the synthesis and electronic transport in bulk polycrystalline Pr-doped SrTiO_3−δ

Recently, we have reported a significant enhancement in the electronic and thermoelectric properties of bulk polycrystalline SrTiO₃ ceramics via praseodymium doping. This improvement was originated from the simultaneous enhancement in the thermoelectric power factor and reduction in thermal conductivity, which was contributed to the non-uniform distribution of Pr dopants. In order to further understand the underlying mechanism, we herein investigate the role of praseodymium doping source (Pr₂O₃ versus Pr₆O₁₁) on the synthesis and electronic transport in Pr-doped SrTiO₃ ceramics. It was observed that the high-temperature electronic transport properties are independent of the choice of praseodymium doping source for samples prepared following our synthesis strategy. Theoretical calculations were also performed in order to estimate the maximum achievable power factor and the corresponding optimal carrier concentration. The result suggests the possibility of further improvement of the power factor. This study should shed some light on the superior electronic transport in bulk polycrystalline Pr-doped SrTiO₃ ceramics and provide new insight on further improvement of the thermoelectric power factor.