Relationship between thermoelectric properties and infrared emissivity of Gd-doped SrO(SrTiO3)2

Compared with perovskite SrTiO 3 , SrO(SrTiO 3 ) 2 exhibits lower thermal conductivity , while maintaining a high Seebeck coefficient , making it a promising material for photothermoelectric conversion. However, the relationship between its infrared and thermoelectric properties remains unexplored. This study examines the effect of Gd doping on these properties of SrO(SrTiO 3 ) 2 . Increased Gd doping induces a gradual transformation of SrO(SrTiO 3 ) 2 -based into a SrTiO 3 -based material, resulting in a composite comprising three phases and a notable reduction in thermal conductivity . At 973 K, the thermal conductivity decreases to a minimum of 1.4 W m −1 K −1 , which is 23 % lower than undoped SrO(SrTiO 3 ) 2 and 51 % lower than SrTiO 3 . Like SrTiO 3 , SrO(SrTiO 3 ) 2 absorbs infrared radiation in the 8–14 μm range. Although the highest ZT value reaches only 0.06 at 973 K, it shows a positive correlation with infrared emissivity. These findings are valuable for advancing the application of thermoelectric effects and the development of high-performance infrared materials.