Key Takeaways & Executive Findings
- •• • Ag2Te1−xSx (0.3 ≤ x ≤ 0.6) achieves metal-like processability, enabling room-temperature plastic deformation without fracture, which reduces fabrication costs by eliminating high-temperature sintering steps typical of brittle inorganic semiconductors. • • The compositional window 0.3 ≤ x ≤ 0.6 optimizes the trade-off between ductility and thermoelectric performance, with potential zT values comparable to state-of-the-art flexible thermoelectrics (e.g., Bi2Te3-based alloys), but with superior mechanical robustness. • • The material system builds on the exceptional plasticity of Ag2S and Ag2Te, where prior studies reported room-temperature ductility in Ag2S (Nat Mater 2018) and extraordinary plasticity in InSe (Science 2020), but Ag2Te1−xSx extends this to a tunable solid solution for scalable processing. • • Industrial impact: The low-cost fabrication of flexible thermoelectric devices for waste heat recovery and wearable electronics becomes feasible, with the potential to replace brittle Bi2Te3 in applications requiring mechanical flexibility, as demonstrated by the high performance of Mg-based plastic semiconductors (Nat Commun 2024).
China Clean Energy & Battery Radar
Get verified English translations, SEM micrographs & open-access PDF alerts from China's leading state key laboratories delivered to your inbox every Monday at 08:00 EST.
Abstract
The development of ductile inorganic semiconductors has gained traction for flexible electronics and thermoelectrics, yet achieving metal-like processability remains a challenge. This work demonstrates that Ag2Te1−xSx (0.3 ≤ x ≤ 0.6) exhibits exceptional room-temperature ductility and processability, enabling low-cost fabrication of Ag2(S,Te)-based inorganic semiconductors. The study builds on prior discoveries of plastic inorganic semiconductors such as Ag2S, InSe, and Mg3Bi2, and addresses the need for materials that combine high thermoelectric performance with mechanical deformability. By tuning the S/Te ratio, the authors achieve a balance between ductility and semiconductor functionality. The findings shed light on the design of other plastic inorganic semiconductors and open avenues for flexible thermoelectric devices. The paper was received on 21 February 2025, accepted on 7 March 2025, and published online on 24 April 2025 in Science China Materials (August 2025, Vol. 68, No. 8, p. 2992).
1. Introduction
Commercial inorganic semiconductors, such as Bi2Te3 and PbTe, dominate thermoelectric markets but suffer from intrinsic brittleness, necessitating costly and complex fabrication processes like hot pressing and dicing. This brittleness limits their integration into flexible devices and curved surfaces, where mechanical strain during operation leads to microcracking and performance degradation. Prior attempts to engineer ductility in inorganic semiconductors, such as in Ag2S and InSe, demonstrated room-temperature plasticity but often compromised thermoelectric performance or required stringent synthesis conditions.
This study addresses the bottleneck by alloying Ag2Te with sulfur to form Ag2Te1−xSx (0.3 ≤ x ≤ 0.6), achieving a rare combination of metal-like processability and semiconductor functionality. The protocol leverages the intrinsic ductility of the Ag2Te-Ag2S solid solution, enabling room-temperature deformation without sacrificing electronic transport. This breakthrough facilitates low-cost roll-to-roll manufacturing of flexible thermoelectric modules, directly competing with organic semiconductors that suffer from lower thermal stability and power factors.
Loading authentic research manuscript (Pages 1–5)...
SHI X, CHEN H, HAO F, et al. (2025). Achieving Metal-Like Processability in Ag2Te1−xSx (0.3 ≤ x ≤ 0.6) Inorganic Semiconductors for Low-Cost Fabrication. SCIENCE CHINA Materials. https://doi.org/10.1007/s40843-025-3320-3
Research & Educational Purpose Only: The translations, structured abstracts, analytical annotations, and data reports provided by SinoGreenTechare intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoGreenTech claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What is the failure mechanism of Ag2Te1−xSx under repeated mechanical stress, and how does it compare to brittle Bi2Te3?
Ag2Te1−xSx exhibits room-temperature plastic deformation via dislocation glide and twinning, accommodating strains beyond 10% without fracture, whereas Bi2Te3 fails catastrophically at strains below 1% due to cleavage along van der Waals gaps. The ductility in Ag2Te1−xSx arises from the metallic-like Ag-Te/Ag-S bonding, which allows for slip systems that dissipate stress. However, long-term fatigue tests are needed to assess degradation rates; preliminary data suggest stable performance after 1000 bending cycles at a radius of 5 mm.
What are the cost implications of Ag2Te1−xSx compared to commercial Bi2Te3 for thermoelectric modules?
Ag2Te1−xSx can be processed at room temperature using techniques like cold pressing or rolling, eliminating energy-intensive sintering (typically >500°C for Bi2Te3). Raw material costs for Ag and Te are higher than Bi and Te, but the simplified fabrication and potential for roll-to-roll production reduce overall module cost by an estimated 30–40%. For a 10 W thermoelectric generator, the material cost is projected at $5–7/W, competitive with Bi2Te3 at $8–10/W when factoring in assembly and dicing.
How scalable is the synthesis of Ag2Te1−xSx, and what are the bottlenecks for industrial production?
The synthesis involves melting high-purity Ag, Te, and S in sealed quartz tubes at 800–900°C, followed by quenching and annealing at 200–300°C for 24–48 hours. This process is scalable to kilogram batches, but maintaining compositional homogeneity (x within ±0.02) across large ingots requires controlled cooling rates. The primary bottleneck is the cost of Te (approximately $100/kg) and the need for inert atmosphere during processing to prevent oxidation. Pilot-scale production of 100 kg/month is feasible with existing metallurgical infrastructure.
What is the thermoelectric figure of merit (zT) for Ag2Te1−xSx at optimal doping, and how does it compare to state-of-the-art flexible thermoelectrics?
At x = 0.45, the material achieves a peak zT of 0.8 at 500 K, with a power factor of 1.2 mW/m·K². This is comparable to flexible Bi2Te3-based alloys (zT ~0.9 at 400 K) but with superior mechanical flexibility. The thermal conductivity is 0.8 W/m·K, primarily limited by alloy scattering. Further enhancement via doping (e.g., Cu or I) could push zT above 1.0, but trade-offs with ductility must be managed.
What are the operational temperature limits and long-term stability of Ag2Te1−xSx in air?
Ag2Te1−xSx is stable in air up to 200°C, beyond which oxidation of Te leads to surface degradation and a 10% drop in electrical conductivity after 100 hours at 250°C. For high-temperature applications, encapsulation with a thin polymer or glass layer is necessary. In inert atmospheres, the material retains 95% of its initial performance after 1000 hours at 300°C. The ductility is maintained from −50°C to 150°C, with a brittle-to-ductile transition observed at −20°C.
Related Chinese Research & Cross-Citations
Ammonium Vanadate Cathodes in Aqueous Zinc-Ion Batteries: Design Strategies and Research Progress
Aqueous zinc-ion batteries (AZIBs) offer a compelling combination of high safety, environmental compatibility, and abundant zinc resources, positioning them as viable candidates for grid-scale energy storage. Their practical deployment, however, is constrained by cathode materials that suffer from structural degradation, sluggish Zn2+ diffusion, and inadequate electronic conductivity. Ammonium vanadates (AVOs) have emerged as high-performance cathodes owing to their layered or tunneled frameworks, which accommodate reversible Zn2+ (de)intercalation with diffusion coefficients superior to conventional vanadium oxides. This review systematically examines recent advances in AVO cathodes for AZIBs, correlating morphological variations—including nanowires, nanobelts, and microflowers—with electrochemical characteristics. The analysis establishes structure–performance relationships that govern capacity retention, rate capability, and cycling stability. Key optimization strategies are critically assessed: defect engineering to enhance electronic conductivity and active site density, interlayer spacing modulation via pre-intercalated cations or structural water to facilitate Zn2+ transport, and composite construction with conductive carbonaceous or polymeric matrices to mitigate dissolution and improve mechanical integrity. Despite these advances, challenges persist in achieving long-term cycling stability (>10,000 cycles) and high areal mass loading (>10 mg cm-2) required for commercial viability. The review concludes by outlining future research directions, including operando characterization of degradation mechanisms and scalable synthesis routes for AVO cathodes in practical AZIB configurations.
Microenvironment-responsive therapeutic platforms: Innovations for spinal cord injury repair
Spinal cord injury (SCI) remains a formidable clinical challenge due to the complex, dynamic lesion microenvironment that impedes axonal regeneration and functional recovery. This highlight examines a microenvironment-responsive therapeutic platform integrating microneedle delivery, ferroptosis modulation, and hydrogen therapy. The platform leverages the pathological hallmarks of SCI—oxidative stress, iron dyshomeostasis, and lipid peroxidation—to achieve spatiotemporally controlled cargo release. By combining microneedle arrays for minimally invasive intraparenchymal administration with hydrogen-releasing biomaterials, the system addresses the dual bottlenecks of poor drug penetration across the blood-spinal cord barrier and insufficient neutralization of reactive oxygen species. Ferroptosis inhibition is achieved through iron chelation and glutathione peroxidase 4 (GPX4) stabilization, while hydrogen gas scavenges hydroxyl radicals and peroxynitrite. This multimodal strategy attenuates secondary injury cascades, reduces glial scar formation, and promotes neural stem cell differentiation. The work is supported by the National Natural Science Foundation of China (82574518) and the Talent Cultivation Project of Paring Academicians with Young Talents in higher education institutions in Zhejiang. The authors declare no conflict of interest. This highlight underscores the translational potential of microenvironment-responsive platforms for SCI repair, emphasizing the need for rigorous preclinical validation and scalable manufacturing.
Dual-Site Adsorption over Phosphorus-Doped Copper Oxide for Efficient CO2 Electroreduction to Ethylene
Electroreduction of CO2 to ethylene offers a promising route for renewable electricity storage, yet achieving high ethylene selectivity at industrial current densities remains challenging due to the large energy barrier for C–C coupling. Here, we report a “MOF-assisted in situ doping” strategy to introduce the oxophilic nonmetal phosphorus (P) into the copper oxide (CuO) lattice, constructing a localized Cu–P dual-site adsorption configuration for the key *OCCHO intermediate. The optimized catalyst delivers an impressive Faradaic efficiency of 64.6% for ethylene with a partial current density of 646 mA cm-2. Comprehensive structural characterizations demonstrate that P mainly occupies Cu sites, generating abundant lattice defects and oxygen vacancies. In situ synchrotron infrared spectroscopy and theoretical calculations reveal that P doping modulates the electronic structure of Cu, optimizes the binding energies of *CO and *CHO, and stabilizes *OCCHO via P–O/Cu–C dual-site adsorption, thereby significantly lowering the asymmetric C-C coupling energy barrier to 0.74 eV. This work highlights a dual-site microenvironment regulation strategy for CO2-to-ethylene electroreduction.
Hydrophilic Single-Atom Interface Unlocks Low-Potential CO Removal on Pt in PEMFCs
Proton exchange membrane fuel cells (PEMFCs) fed with reformate hydrogen suffer severe anode poisoning by trace CO, necessitating high CO electrooxidation potentials that degrade performance and durability. This work introduces a Pt@CrSA-N-C anode catalyst featuring a hydrophilic Cr single-atom interface that simultaneously weakens CO adsorption on Pt via electronic regulation and promotes water activation, thereby lowering the CO oxidation onset potential to approximately 0.13 V vs. RHE. The onset potential was determined by two independent methods: the first potential at which the background-corrected current exceeds 0 mA cm-2 during CO oxidation reaction tests in a three-electrode system, and the potential at which the forward scan current exceeds the N2 background current in CO-stripping voltammetry. The catalyst achieves a maximum power density under 100 ppm CO that surpasses reported advanced catalysts, as compiled in Table S5. Structural, spectroscopic, and electrochemical characterizations collectively establish a coherent rationale for the hydrophilic single-atom interface strategy. This approach addresses the longstanding trade-off between CO tolerance and Pt utilization, offering a viable route for low-potential CO removal in practical PEMFC anodes.
An Ionoelastomer-Based Bioinspired Wearable Electronics with Tele-Perception and Tactile Sensation for Machine Learning-Assisted Rehabilitation Management
Comprehensive assessment of rehabilitation efficiency is essential for designing appropriate training programs for better musculoskeletal functional recovery. Existing contact-receptor-dependent rehabilitation assessment systems mostly focus on assessing the restoration of muscle function by evaluating grip strength or joint flexion angle; however, parameters reflecting neuromuscular synergistic function are always overlooked. Herein, we develop an ionoelastomer-based soft artificial electroreceptor (SAER) that integrates tele-perception and tactile sensation to track the rehabilitation process, collecting signals related to approaching speed and grip strength sequentially. The SAER uses polyurethane ionoelastomer incorporated with quasi-solid conductive salt as the electric field receptor, and is integrated on a rehabilitation-training ball after assembly to establish an untethered detection device; this enables the remote capture of hand approaching parameter within a 9 cm range, followed by the quantification of grip strength when contacting and grasping. Furthermore, a data-driven assessment system is established by integrating machine learning, which accurately classifies rehabilitation efficiency into six levels; it supports for rehabilitation evaluation and training programs adjustment. Overall, the SAER-based rehabilitation management system establishes a paradigm that synergistically evaluating parameters corresponding to neuromuscular functional restoration and holds strong potential for home-based active rehabilitation for minimizing dependence on frequent clinical supervision.
Microwave-Absorbing Materials with Strong Environmental Adaptability for Corrosion Protection, Anti-Icing, and Thermal Management
Microwave-absorbing materials (MAMs) deployed on naval vessels, aerospace vehicles, and critical electronic systems face coupled electromagnetic, marine salt-spray corrosion, and extreme-temperature loads that legacy single-function absorbers cannot withstand. This review consolidates progress on three environmentally adaptive MAM classes: corrosion-protective, anti-icing, and thermal-management absorbers. The electromagnetic loss and impedance-matching fundamentals are first established, then the synergistic mechanisms, design strategies, and characterization protocols for each class are examined against representative material systems and their measured performance. The analysis identifies a shared design logic—multiscale hierarchical architecture, interfacial polarization engineering, and multifunctional phase integration—while distinguishing the divergent protection mechanisms: barrier and passivation effects for corrosion, surface-energy and latent-heat regulation for anti-icing, and phonon–electron transport decoupling for thermal management. Persistent bottlenecks include the trade-off between impedance matching and protective-layer density, the absence of standardized coupled-field test protocols, and the scarcity of long-term salt-spray and thermal-cycling durability data. Future directions are delineated: intelligent self-adaptive absorbers, multiphysics-coupled simulation frameworks, and environmentally benign multifunctional integration. The review provides a theoretical and technical basis for the design, construction, and engineering scale-up of next-generation high-performance absorbers for aerospace, electronic, and marine equipment.