THERMOELECTRIC PROPERTIES OF COPPER-DOPED BI2TE2.85SE0.15 CRYSTALS

The effect of copper dopant on the thermoelectric and transport proper ties of Czochralski-grown Bi2Te2.85Se0.15 crystals is studied. The eff ective distribution coefficient of copper is determined to be k(eff) = 0.2. Doping with small amounts of copper increases carrier mobility a nd the thermoelectric figure of merit of the crystals: Z = (3.1-3.4) x 10(-3) K-1 in the temperature range 220-350 M. Solid solutions grown from charges containing less than or equal to 0.1 at, % Cu possess sta ble properties, which are found to change little during annealing at 2 80 degrees C in air for 150 h.