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.