Dense dislocations induced ductile SnTe thermoelectric semiconductor over a wide range of temperatures

Most inorganic thermoelectric semiconductors are intrinsically brittle,restricting the application of ther-moelectric materials.Therefore,developing ductile thermoelectric materials is crucial to thermoelectric technology applications.In this work,single-phase SnTe bulks with dense dislocations were prepared by melting quenching combined with spark plasma sintering.The resulting SnTe thermoelectric materials exhibited a large compressive strain of∼7.5%at room temperature,originating from high-density pre-existing mobile dislocations.The initiation of localized slip bands and preferred slip system were also identified by first-principles simulation.Detail microstructural characterizations reveal that the thermal activated dislocation emission and migration lead to higher compressive strains at intermediate tem-peratures.At 673 K,the deformation mechanism changed from dislocation mediated to grain boundary mediated plasticity,resulting in an ultra-high compressive strain of∼42%.In sum,new insights into the mechanical behavior of SnTe thermoelectric material over a wide range of temperatures were provided.This work offers the dislocation engineering strategy to design ductile thermoelectric materials for flexi-ble electronics and energy systems.