Novel method for metal-oxide glass composite fabrication for use in thermoelectric devices

Abstract

A novel method for thermoelectric materials fabrication using a reduction of oxide precursors in hydrogen was reported. On the example of Bi–Sb, Bi–Sb–Te and Te–Ag–Ge–Sb compounds it was shown that this simple and easy method is suitable for fabrication of two-, three- and even multicomponent thermoelectric materials. It allows controlling a composition, microstructure and even type a of electrical charge carriers. As a result of reduction of oxide precursors a layered structure with an average thickness of layers equal tens of nanometers was formed. At the near-room temperature the best material with a figure of merit (ZT) close to 0.4 was Bi0.8Sb1.2Te3Ox reduced at 340°C for 10h. At 350°C a value of ZT=0.8 was reached by the (GeTe)0.85(AgSbTe2)0.15 (TAGS85) sample reduced twice at 400°C for 10h.