Prospective Thermoelectric Materials: (AgSbTe2)100-x(SnTe)x Quaternary System (x=80, 85, 90, and 95)

(AgSbTe2)(100-x)(GeTe)(x) is an important p-type thermoelectric materials with high thermoelectric figure of merit (ZT). We report on the high temperature electrical and thermal transport properties of (AgSbTe2)(100-x)(SnTe)(x) compounds with x = 80, 85, 90, and 95. Similar to (AgSbTe2)(100-x)(GeTe)(x) (TAGS-x), (AgSbTe2)(100-x)(SnTe)(x) (TASS-x) alloys show very low thermal conductivity. The lowest lattice thermal conductivity value for TASS-85 is 0.3 W/m . K at room temperature, close to the minimum value for these types of materials. The Hall effect study demonstrates that the hole mobility in (AgSbTe2)(100-x)(SnTe)(x) compounds is higher than that in (AgSbTe2)(100-x)(GeTe)(x). Among all the compositions, (AgSbTe2)(15)(SnTe)(85) possesses the largest power factor and lowest thermal conductivity, thus resulting in the highest ZT of 0.75 at 800 K. Further optimization of the hole density in (AgSbTe2)(100-x)(SnTe)(x) may increase ZT to values comparable to those of TAGS-x compounds.