Synergetic Enhancement of Strength–Ductility and Thermoelectric Properties of Ag₂Te by Domain Boundaries

Abstract

Simultaneously improving the mechanical and thermoelectric (TE) properties is significant for the engineering applications of inorganic TE materials. In this work, a novel nanodomain strategy is developed for Ag2Te 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 achieve a 45% improvement in average ZT value. The domain boundaries (DBs) provide extra sites for dislocation nucleation while pinning the dislocation movement, resulting in superior strength and ductility. In addition, phonon scattering induced by DBs suppresses the lattice thermal conductivity of Ag2Te and also reduces the weighted mobility. These findings provide new insights into grain and DB engineering for high‐performance inorganic semiconductors with robust mechanical properties.

High Power Factor Flexible Ag2Te Film on Nylon by a Wet Chemical Method for Power Generator

“…Compared with the XRD peak intensity of powder 3, the XRD peak intensity of film 3 is significantly enhanced, especially its peak intensity of (300). This is because the crystallinity improves after hot pressing, and the grain growth has a certain degree of orientation during hot pressing, which has also been reported in refs , , and .…”

“…Ag 2 Te shows a low density of state-effective mass, leading to high carrier mobility. In addition, it has a relatively low intrinsic κ l and is considered to be a promising TE material. − For example, Wang et al prepared bulk Ag 2 Te with high-density nanodomains and enhanced the interfacial scattering of phonons. The Ag 2 Te bulk sample exhibits a PF value of 1026 μW m –1 K –2 at 300 K and a maximum ZT value of 0.6 at 400 K. To obtain Ag 2 Te films on flexible substrates, various methods for synthesizing Ag 2 Te nanostructures have been employed, among which the template method and hydrothermal method are widely used.…”

Hidden structures: a driving factor to achieve low thermal conductivity and high thermoelectric performance

“…So far, a number of cutting-edge superionic TE materials have been identified and developed with exceptionally low κ lat and superior TE performance, with the maximum z T s reaching 2.0 or above, e.g. , AgCrSe 2 , 28 CuCrSe 2 , 305,306 InTe, 140,292 Ag 2 (S, Se, Te), 307–312 Cu 2− δ (S, Se, Te), 27,29,313–321 Cu or Ag-based argyrodites, 322–326 AgCuTe, 327 etc. Experimental characterization through X-ray or neutron PDF analysis to probe the subtle structural disorders and atomic dynamics provides a basis for understanding ultralow thermal conductivity in such PLECs.…”

Achieving High Thermoelectric Performance in ZnSe-Doped CuGaTe2 by Optimizing the Carrier Concentration and Reducing Thermal Conductivity

“…The increasingly severe fossil fuel crisis and greenhouse effect are placing unprecedented pressure on energy supply. , Thermoelectric materials, due to their ability to mutually convert thermal energy into electrical energy, have garnered significant attention as they can efficiently convert industrial waste heat into electrical energy. , Typically, thermoelectric material properties were evaluated using the dimensionless parameter ZT = S 2 σ T /(κ l + κ e ), , where S represents the Seebeck coefficient, σ stands for the electrical conductivity, T is the absolute temperature, κ l is the lattice thermal conductivity, and κ e is the electronic thermal conductivity. , Achieving high ZT value necessitates elevated electrical conductivity and Seebeck coefficient, while maintaining relatively low thermal conductivity. − However, there exists a coupled relationship among S, σ, and κ e making it challenging to solely control any individual parameter. − Therefore, researchers have explored various methods for comprehensive control, such as adjusting carrier concentration and band engineering to improve electrical performance, − and implementing phonon engineering to reduce thermal conductivity. , …”