Bi1-xSrxCuSeO oxyselenides as promising thermoelectric materials

p-type BiCuSeO, a layered oxyselenide composed of conductive (Cu2Se2)(2-) layers alternately stacked with insulating (Bi2O2)(2+) layers, shows an enhancement of the electrical conductivity after substituting Bi3+ by Sr2+, from 470 S m(-1) (BiCuSeO) to 4.8 x 10(4) S m(-1) (Bi0.85Sr0.15CuSeO) at 293 K. Coupled to high Seebeck coefficients, this leads to promising values of the thermoelectric power factor that exceeds 500 mu W m(-1) K-2 at 873 K. Moreover, the thermal conductivity of these layered compounds is lower than 1 W m(-1) K-1 at 873 K. Maximum ZT values reach 0.76 at 873 K, making this family promising for thermoelectric applications in the medium temperature range. (C) 2010 American Institute of Physics. [doi:10.1063/1.3485050]