Abstract
The ternary chalcogenides AgSbSe2 and AgSbTe2 are both p-type semiconductors with excellent thermoelectric potential. The phase relations and microstructures along the pseudo-binary AgSbSe2-AgSbTe2 were investigated using naturally solidified and/or thermally equilibrated alloys, with starting compositions of non-stoichiometric Ag20Sb30Se50-xTex (x=0,5,10,15,20,25,30,35,40 and 45) and stoichiometric Ag25Sb25Se50-yTey (y=0,5,10,15,20,25,30,35,40 and 45). Selective alloys were synthesized using the modified Bridgman method, and the corresponding electronic transport properties were measured. It was found that the electrical resistivity of non-stoichiometric Ag20Sb30Se50-xTex varied with respect to the Te/Se ratio, and reached a minimum value of 8.9(mΩ-cm) at 35at%Te (ie., Ag20Sb30Se15Te35) at room temperature. The reduced electrical resistivity of the 35at%Te alloy might result from the homogeneous microstructure and the absence of secondary phase. In particular, the carrier concentrations of all the Bridgman-grown non-stoichiometric Ag20Sb30Se50-xTex alloys located in the heavily-doped semiconductor range (n~1019~1020 cm-3), revealing that those non-stoichiometric alloys might serve as prospective candidates in the applications of thermoelectricity