Achieving metal-like malleability and ductility in AgTe S inorganic thermoelectric semiconductors with high mobility.

Inorganic semiconductor AgTe S 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 AgTe S ( = 0.3, 0.4, and 0.5) composites can exhibit excellent compressive strain up to 70% if the monoclinic AgTe phase, which commonly exists in the matrix, is eliminated. Significantly, an ultra-high tensile elongation reaching 107.3% was found in AgTeS, 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 V s 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.