A high thermoelectric figure of merit ZT > 1 in Ba heavily doped BiCuSeO oxyselenidesElectronic supplementary information (ESI) available: Typical samples (bar and coin) used in this study (Fig. S1); temperature dependence of heat capacity, thermal diffusivity, Lorenz number, and electronic thermal conductivity (Fig. S2) for Bi1xBaxCuSeO samples; and thermoelectric properties of the samples before and after annealing treatments (Fig. S3). See DOI: 10.1039/c2ee22622g

• Main Authors: Li, Jing, Sui, Jiehe, Pei, Yanling, Barreteau, Celine, Berardan, David, Dragoe, Nita, Cai, Wei, He, Jiaqing, Zhao, Li-Dong
• Format: Article
• Language: English
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/c2ee22622g

A high ZT value of 1.1 at 923 K in the BiCuSeO system is achieved via heavily doping with Ba and refining grain sizes (200-400 nm), which is higher than any thermoelectric oxide. Excellent thermal and chemical stabilities up to 923 K and high thermoelectric performance confirm that the BiCuSeO system is promising for thermoelectric power generation applications. A high ZT value of 1.1 at 923 K in BiCuSeO oxyselenides has been achieved by the combination of optimizing electrical transport properties through Ba heavily doping and reducing thermal conductivity through refining grain sizes. High performance along with excellent thermal and chemical stabilities makes BiCuSeO very promising for thermoelectric applications.