Achieving metal-like malleability and ductility in Ag(2)Te(1-x)S(x) inorganic thermoelectric semiconductors with high mobility

Inorganic semiconductor Ag(2)Te(1-x)S(x) has been recently found to exhibit unexpected plastic deformation with compressive strain up to 30%. However, the origin of the abnormal plasticity and how to simultaneously achieve superb ductility and high mobility are still elusive. Here, we demonstrate that crystalline/amorphous Ag(2)Te(1-x)S(x) (x = 0.3, 0.4, and 0.5) composites can exhibit excellent compressive strain up to 70% if the monoclinic Ag(2)Te phase, which commonly exists in the matrix, is eliminated. Significantly, an ultra-high tensile elongation reaching 107.3% was found in Ag(2)Te(0.7)S(0.3), which is the highest one yet reported in the system and even surpasses those achieved in some metals and high-entropy alloys. Moreover, high mobility of above 1000 cm(2) V(−1) s(−1) at room temperature and good thermoelectric performance are simultaneously maintained. A modified Ashby plot with ductility factor versus carrier mobility is thereby proposed to highlight the potential of solid materials for applications in flexible/wearable electronics.