JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2025
·Vol. 46
·期 2
·117772
·
IF 6.2
Jingdan Lei,Chunhui Wang,Xiaoyun Yang,Xiwei Zhang,Di Yuan,Xu-Jin Ge,Shike Zhang,Gui Yang,Chao Wang
AgCuTe has attracted significant interest due to their superior electrical and thermal transport characteristics. In this work, we focuses on investigating the effects of Se and S solid solution on AgCuTe thermoelectric properties. A series of AgCu(Te, Se, S) solid solutions were synthesized via melting reaction. We found these compositions effectively inhibited the typical hexagonal-to-cubic phase transition and showed features of secondary phase segregation, such as Ag 2 Te, Cu 2 Te, and Cu 2 S. These nano- to microscale chemistry fluctuations significantly affect the thermoelectric transport properties, particularly thermal transport, resulting in an exceptional low lattice thermal conductivity of 0.19 W m −1 K −1 , which was approaching the amorphous limits. Consequently, a maximum figure of merit zT up to 1.4 was obtained at 723 K for AgCuTe 0.65 Se 0.1 S 0.25 sample. This work investigates the relationships between composition, structure, and thermoelectric properties of AgCuTe, providing substantial support for the further development of high-performance AgCuTe-based materials.
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DOI
高影响因子
Nano Energy
·
2024
·
IF 16.8
Xinpeng Luan,Jianbo Li,Shipeng Wu,Guibin Zhang,Hexige Wuliji,Jun Wang
AgCuTe, a p-type medium-temperature thermoelectric material, exhibits great potential as a candidate for converting waste heat into electricity owing to its low thermal conductivity and high thermoelectric performance. However, an unstable phase structure of the material system has hindered the direct observation of various point defects contacting with high performance, despite their predicted possibilities solely based on first-principles calculations. Here, we present the novel observation of Te interstitial atoms together with other point defects, planar defects, and nanoscale atomic aggregation for the first time in the Zn-doped and Te non-stoichiometric AgCuTe system, employing a nanoscale perspective. Through our investigation, we disclose the remarkable coexistence of multidimensional defects, thereby resolving the previously conflicting opinions regarding point defects in this system. The effective control of these defects is crucial for achieving high thermoelectric performance. The Zn Cu point defects regulate carrier concentration and Seebeck coefficient by influencing phase proportion and carrier effective mass. While maintaining the material's inherently large power factor ( PF ), thermal conductivity is effectively reduced through grain refinement and multiscale defect scattering. As a result, the dimensionless thermoelectric figure of merit ( ZT ) of approximately ∼ 1.16 is achieved at 773 K. By altering Te content, a coexistence of diverse defects is introduced, leading to intricate microstructures and phase structures. Consequently, a significant reduction in thermal conductivity is observed. The coexistence of multidimensional defects, as well as their impact on microstructure and thermoelectric transport properties, holds significant implications for the performance control of functional materials.
研究领域:
材料科学
·
物理学
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DOI
高影响因子
Small
·
2024
·Vol. 20
·期 45
·2403852
·
IF 13
Xinxin Wang,Chao Wang,Yajing Wang,Min Hao,Shengqiang Cui,Xudong Huang,Chunhui Wang,Jing Chen,Zhenxiang Cheng,Jianli Wang
N-type PbSe thermoelectric materials encounter challenges in improving the power factor due to the single-band structure near the Fermi level, which obstructs typical band convergence. The primary strategy for enhancing the thermoelectric figure of merit (ZT) for n-type PbSe involves reducing lattice thermal conductivity (κ lat ) by introducing various defect structures. However, lattice mismatches resulting from internal defects within the matrix can diminish carrier mobility, thereby affecting electrical transport properties. In this study, n-type AgCuTe-alloyed PbSe systems achieve a peak ZT value of ≈1.5 at 773 K. Transmission electron microscopy reveals nanoprecipitates of Ag 2 Te, the room temperature second phase of AgCuTe, within the PbSe matrix. Meanwhile, a unique semi-coherent phase boundary is observed between the PbSe matrix and the Ag 2 Te nanoprecipitates. This semi-coherent phase interface effectively scatters low-frequency phonons while minimizing damage to carrier mobility. Additionally, the dynamic doping effect of Cu atoms from the decomposition of AgCuTe within the matrix further optimize the high-temperature thermoelectric performance. Overall, these factors significantly enhance the ZT across the whole temperature range. The ZT value of ≈1.5 indicates high competitiveness compared to the latest reported n-type PbSe materials, suggesting that these findings hold promise for advancing the development of efficient thermoelectric systems.
研究领域:
材料科学
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凝聚态物理
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能源材料
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纳米结构工程
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热电转换
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DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2022
·Vol. 24
·期 44
·27105-27113
·
IF 3.945
Panpan Peng,Chao Wang,Lanwei Li,Shuyao Li,Jing Chen,Pengya Fan,Rui Du,Haotian Si,Zhenxiang Cheng,Jianli Wang
Endotaxial nanostructures can reduce lattice thermal conductivity through enhancing phonon scattering without affecting electrical transport, leading to a high thermoelectric performance. On the other hand, band engineering can enhance electrical transport by improving the Seebeck coefficient through valence band convergence and the resonance level. In this paper, the synergistic effect of band engineering and endotaxial nanostructures was implemented in SnTe thermoelectric materials by alloying with AgCuTe and doping with Indium. The positron annihilation lifetime spectra show that the vacancy concentration in SnTe was reduced after alloying with AgCuTe, which led to a decreasing hole concentration and improved carrier mobility. Additionally, the diffusion of Ag in the matrix during the preparation can facilitate valence band convergence. Therefore, the power factor of SnTe is greatly increased to 18 μW cm−1 K−2 at 800 K, which can be further increased to 21.4 μW cm−1 K−2 at 800 K after In doping due to resonance level formation. Meanwhile, Cu2Te endotaxial nanostructures also can be observed in the TEM image after SnTe alloying with AgCuTe. So, the lattice thermal conductivity significantly reduced to 0.93 W m−1 K −1 in In-doped and AgCuTe-alloyed SnTe. Finally, we obtain an enhanced ZT value of 1.14 in Sn1.02In0.01Te–1%AgCuTe at 800 K.
研究领域:
材料科学
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凝聚态物理
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功能材料
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热电转换
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纳米结构调控
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半导体物理
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能源材料
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DOI
高影响因子
Journal of Materials Chemistry A
·
2022
·Vol. 10
·期 12
·6701-6712
·
IF 14.511
Lanwei Li,Wenya Zhai,Chao Wang,Yanqun Chen,Shuyao Li,Pengya Fan,Zhenxiang Cheng,Gui Yang,Jianli Wang,Yanli Mao
Nanoengineering has always been an effective way to optimize thermoelectric materials. Multi-layered nanostructures can maximize the phonon scattering efficiency and greatly reduce the thermal conductivity, thus improving the thermoelectric performance. In this work, multi-layered nanostructures are constructed in AgCuTe by alloying Cu2Se, which strongly scatters full-wavelength phonons and achieves a new low thermal conductivity at 723 K. High-resolution transmission electron microscopy shows that additional phase boundaries, multiple Moiré fringes and regular nanophases are formed after alloying Cu2Se. Moiré fringes form high density dislocations and strong stress fields in AgCuTe, which can greatly scatter multi-wavelength phonons. In addition, the Cu+ ions generated after the dissolution of a small amount of Cu2Se participate in the electrical transport, which optimizes the electrical performance. In the end, the AgCuTe–1%Cu2Se sample achieves the lowest thermal conductivity of ∼0.45 W m−1 K−1 at 723 K, which is much lower than the average level of published AgCuTe-based materials. At the same time, between 523 K and 723 K, the average ZT ∼ 1.13 of AgCuTe–1%Cu2Se reached the leading level. This work provides a new strategy for further reducing the thermal conductivity of AgCuTe-based materials.
研究领域:
材料科学
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纳米技术
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热电学
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固体物理
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DOI
高影响因子
ACS Applied Energy Materials
·
2026
·Vol. 9
·期 15
·10000-10010
·
IF 5.5
Zheng Qixian,Lai Zhangheng,Chen Xiangbin,Qi Ning,Chen Zhiquan
As a phonon-liquid electron-crystal (PLEC), AgCuTe exhibits unique advantages due to its complex crystal structure and inherently low lattice thermal conductivity. However, the high concentration of Ag/Cu cation vacancies in AgCuTe leads to an excessively high carrier concentration, which restricts its thermoelectric performance. In this study, both the phase composition and carrier concentration were tailored by tuning the Ag/Cu content in AgCuTe. As the Ag/Cu content increases, the phase composition evolves from Ag 2 Te and Cu 2 Te secondary phases to a predominant AgCuTe phase. Seebeck coefficient measurements reveal that AgCuTe exhibits a conduction type transition upon tailoring the Ag/Cu content. The Ag/Cu-deficient samples exhibit n-type semiconducting behavior at room temperature. Increasing the Ag/Cu content gradually reduces the Ag 2 Te secondary phase, which in turn decreases electron carriers. Meanwhile, positron annihilation measurements reveal that more cation vacancies are introduced with increasing Ag/Cu content, which afford a high concentration of hole carriers and thus switch samples to p-type conduction. At temperatures higher than 527 K, all the samples exhibit a pure cubic AgCuTe phase and show p-type conduction behavior. The increased Ag/Cu content reduces Hall carrier concentration, leading to enhanced power factor and decreased electronic thermal conductivity. In addition, the increased Ag/Cu content further reduces the lattice thermal conductivity by decreasing the sound velocity and enhancing lattice anharmonicity. Collectively, these factors realize synergistic optimization of thermoelectric performance. The (AgCu) 1.06 Te sample achieves a remarkable zT max value of 1.39 at 737 K, with an average zT ( zT ave ) of 1.29 between 523 and 737 K, which show enhancement of 74 and 94% compared with the pristine AgCuTe, respectively. The Ag/Cu excess samples also demonstrate excellent thermal stability up to 873 K. This work provides a strategy for further optimizing the thermoelectric performance of AgCuTe-based materials.
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DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2025
·
IF 3.4
Jingdan Lei,Chunhui Wang,Xiaoyun Yang,Huijuan Geng,Xu-Jin Ge,Xinxin Wang,Shengqiang Cui,Yajing Wang,Gui Yang,Chao Wang
Recently, AgCuTe has garnered growing interest as a promising superionic conductor. Herein, we investigated the thermoelectric property changes induced by introducing SnTe into AgCuTe. The introduction of SnTe enabled a nearly 20% enhancement in the Seebeck coefficient. Combining with the relatively high electrical conductivity, a power factor of 9.3 μW cm–1 K–2 was achieved at 723 K. Particularly, by introducing SnTe into AgCuTe, multiple-scale defects including atomic-scale lattice disorder, nanoprecipitates, and micrometer-scale grain boundaries were constructed as an effective hierarchical phonon scattering mechanism. Owing to the scattering of full-wavelength phonons, we yielded a low lattice thermal conductivity of 0.2 W m–1 K–1, which approached the amorphous limits. Consequently, a maximum zT up to 1.1 was obtained at 723 K for AgCuTe–3 wt % SnTe, which was nearly 40% higher than that of pristine AgCuTe.
研究领域:
材料科学
·
热电学
·
固体物理
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产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2024
·
IF 5.4
Bin Xiao,He Yang,Jianbo Li,Jun Wang
The rigid crystalline sublattice of Te ions in AgCuTe provides an effective electrical transport channel, enabling AgCuTe to exhibit good electrical properties. However, the appearance of vacancies or interstitial atoms within the Te2– rigid anionic framework poses significant challenges both theoretically and experimentally. Here, we are the first to discover the existence of localized Tei, VCu, and VAg multiple defects in the AgCuTe phase, as well as a highly ordered arrangement of VCu in the Cu2Te phase of AgCuTe1–z samples, by only fine-tuning the Te stoichiometric ratio. The formation of these localized defects arises from the excess precipitation of Ag and Cu during the process, which enhances phonon scattering and reduces thermal conductivity. Simultaneously, the total cation content in AgCuTe1–z samples increases relative to the anion, thereby optimizing total intrinsic vacancies and carrier concentration. As a result, there is a 311% increase in the power factor and a 44% decrease in the lattice thermal conductivity at room temperature, leading to a 54% net increase in ZT compared to that of pristine AgCuTe. This approach is expected to be a universal modification strategy for enhancing the thermoelectric properties of other Te-based anionic framework superionic conductor materials.
研究领域:
材料科学
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热电学
·
固体物理
·
缺陷工程
·
纳米材料
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Lanwei Li,Wenya Zhai,Chao Wang,Shuyao Li,Panpan Peng,Pengya Fan,Gui Yang
With the development and application of thermoelectric (TE) devices, it requires not only high-performance of TE materials but also high mechanical properties. Here, we report a medium-temperature liquid material, AgCuTe, with high mechanical properties. The results demonstrate that AgCuTe possesses a multiphase structure characterized by abundant grain boundaries, resulting in reduced lattice thermal conductivity and inherently high mechanical strength. Furthermore, nano-SiC was alloyed into the AgCuTe material to further improve its mechanical and TE properties. Nano-SiC exhibited a button-like distribution within the grain boundaries, introducing a pinning effect that significantly elevated the Vickers hardness of the samples. Additionally, nano-SiC induced strong lattice distortion energy in the vicinity, which promotes Ag/Cu ions to escape from the lattice and enhances the liquid-like behavior of Ag/Cu ions. Finally, these enhancements led to a 21% improvement in the mechanical properties and a 40% improvement in the TE properties for AgCuTe. Notably, AgCuTe achieved its peak TE performance, with a latest peak ZT value of 1.32 at 723 K. This research expands the potential applications of AgCuTe.
研究领域:
材料科学
·
热电学
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力学性能
·
纳米复合材料
·
固体物理
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DOI
高影响因子
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