Synergetic Enhancement of Strength-ductility and Thermoelectric Properties of Ag 2 Te by Domain Boundaries.

Simultaneously improving the mechanical and thermoelectric properties is significant for the engineering applications of inorganic thermoelectric materials. In this work, a novel nanodomain strategy was developed for Ag 2 Te compounds to yield 40% and 200% improved compressive strength (160 MPa) and fracture strain (16%) when compared to domain-free samples (115 MPa and 5.5%, respectively). The domained samples also achieved a 45% improvement in average ZT value. The domain boundaries provide extra sites for dislocation nucleation while pinning the dislocation movement, resulting in superior strength and ductility. In addition, phonon scattering induced by domain boundaries suppressed the lattice thermal conductivity of Ag 2 Te and also reduces the weighted mobility. These findings provided new insights into grain and domain boundary engineering for high-performance inorganic semiconductors with robust mechanical properties. This article is protected by copyright. All rights reserved.