Thermoelectric Properties of Single Crystal EuBiSe₃ Fiber

EuBiSe₃, a narrow-band-gap semiconductor, is synthesized by introducing the rare earth element Eu into Bi₂Se₃. It can be a potential thermoelectric material due to the relatively complex crystal structure and large effective mass. In this study, the thermoelectric properties of a EuBiSe₃ fiber with a diameter of 167 μm have been characterized systematically for the first time from 80  to 290 K by applying our developed T-type method, including thermal conductivity, electrical conductivity and Seebeck coefficient. The thermal conductivity decreases from 1.08 to 0.88 W m⁻¹ K⁻¹ dominated by three-phonon Umklapp scattering and then increases to 1.20 W m⁻¹ K⁻¹ as the temperature increases to 290 K. The electrical conductivity varies from 4209  to 5240 S m⁻¹ in the studied temperature range. The absolute Seebeck coefficient increases slightly to 204 µVK⁻¹ with the increase of temperature. The highest value of the determined dimensionless figure of merit ZT is 0.05, obtained at 290 K.