ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Tian Yu,Suiting Ning,Qian Liu,Tingting Zhang,Xiangbin Chen,Ning Qi,Xianli Su,Xinfeng Tang,Zhiquan Chen
As a liquid-like material, CuAgSe has high carrier mobility and ultralow lattice thermal conductivity. It undergoes an n–p conduction-type transition during β- to α-phase transition with increasing temperature. Moreover, optimization of the thermoelectric performance of CuAgSe is rather difficult, owing to the two-carrier conduction in this material. In this work, we reported the free tuning of the conduction type and thermoelectric performance of CuAgSe by manipulating the cation vacancies. Positron annihilation measurements reveal that the increase in CuAg content can effectively suppress the cation vacancies and reduce the hole carrier concentration, resulting in n-type conduction at high temperatures. Doping with Zn at the Cu sublattice in the CuAg-excessive CuAgSe can further decrease the number of vacancies, leading to a significant decrease in hole carrier concentration. Furthermore, the reduction of vacancies leads to weakening of carrier scattering. As a result, carrier mobility is also enhanced, thus improving the thermoelectric performance of n-type CuAgSe. On the other hand, high-performance p-type CuAgSe can be achieved by decreasing the CuAg content to introduce more cation vacancies. Ultimately, both n-type and p-type CuAgSe with superb thermoelectric performance are obtained, with a zTmax of 0.84 in Cu1.01Ag1.02Zn0.01Se (n-type) and 1.05 in (CuAg)0.96Se (p-type) at 600 K and average zT of 0.77 and 0.94 between 470 and 630 K for n-type and p-type, respectively.
研究领域:
材料科学
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热电学
·
固体物理学
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DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 8
·4088-4101
·
IF 11.9
Tian Yu,Suiting Ning,Tingting Zhang,Xiangbin Chen,Qian Liu,Ning Qi,Zhiquan Chen,Xianli Su,Xinfeng Tang
As one kind of superionic conductor, CuAgSe is a promising thermoelectric material due to its extremely low thermal conductivity and high electron mobility. In this study, the electrical and thermal properties of CuAgSe were collaboratively optimized by changing the chemical composition. Seebeck coefficient measurements reveal that stoichiometric and CuAg-deficient CuAgSe materials show n–p transition with the increase of temperature. In contrast, the Se-deficient CuAgSe still shows n-type conduction in the α-phase at high temperatures. Positron annihilation measurements indicate that there are large amounts of cation vacancies such as Ag and Cu vacancies in the stoichiometric and CuAg-deficient samples, which provide a high concentration of hole carriers and are responsible for the n–p transition at high temperatures. The number of vacancies decreases gradually with increasing CuAg content, and in the Se-deficient CuAgSe, VAg–Se divacancies are formed, which further results in a sufficient decrease of hole carriers. As a result, the Se-deficient samples still show n-type conduction in the α phase. Our results indicate that vacancy defects are the key factors that determine the conduction type in CuAgSe, which can be tuned by the chemical composition. In addition, superb thermoelectric performance was achieved in both p-type and n-type CuAgSe, with maximum ZT of 0.96 at 573 K in (CuAg)0.96Se (p-type) and 0.55 at 630 K in (CuAg)1.02Se and (CuAg)1.04Se (n-type).
研究领域:
材料科学
·
热电学
·
固体物理学
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DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2025
·Vol. 27
·期 37
·19939-19949
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IF 2.9
Zhangheng Lai,Xiangbin Chen,Qixian Zheng,Zhengmao Luo,Zhongshuo Li,Ning Qi,Zhiquan Chen
Polycrystalline SnSe has been widely explored due to its relatively low thermal conductivity. Yet its thermoelectric performance is limited due to its poor electrical conductivity. In this work, polycrystalline SnSe alloyed with different contents of CuAgSe were fabricated by a high-energy balling and melting method, combined with spark plasma sintering. It is revealed that substitution of Ag and Cu at Sn sites actually enhances the electrical conductivity, especially under Sn-deficient circumstances where the formation energy of AgSn is lowered. When there was excessive addition of CuAgSe, the hole carrier concentration was reduced due to the formation of Agi, which acts as an electron donor. Additionally, partial substitution of Ag and Cu into the Sn vacancies slightly improves the Hall mobility and the density of states effective mass. With increased electrical conductivity while maintaining a stable Seebeck coefficient, the Sn0.99Se sample alloyed with 0.75% CuAgSe attains a maximum power factor of 6.40 μW cm−1 K−2 at 847 K. In addition, a peak zT value of 0.97 at 847 K is achieved, combined with only a marginally decreased thermal conductivity, thereby exhibiting a prominent improvement over that of the pure SnSe sample. The present work opens up a new perspective for optimizing the thermoelectric performance of SnSe compounds with the strategy of tuning the content of Sn and alloying with CuAgSe.
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 21
·14998-15008
·
IF 2.993
Zuo Yong,Liu Yu,He Qiong-Ping,Song Ji-Ming,Niu He-Lin,Mao Chang-Jie
CuAgSe is a promising thermoelectric (TE) material for its superior carrier mobility and ultralow lattice thermal conductivity. Herein, we present a scalable colloidal method to prepare monodisperse CuAgSe nanocrystals with high yield. The collected powder sample was washed by a sulfur-free reagent of NaNH 2 to remove the surface organic ligands (CuAgSe-W) and then annealed (CuAgSe-W-A). Both kinds of ligand-free samples were then hot pressed into dense pellets to measure the TE property. The results revealed that the crystal structure of both samples changed from low-temperature β-phase to high-temperature α-phase at around 465 K. Sample CuAgSe-W shows interesting temperature-dependent transition from N -type to P -type, which could be potentially used as thermal control transistor. Sample CuAgSe-W-A does not display this transition state but it exhibits potential for intermediate temperature TE applications with a figure-of-merit zT reaching 0.68 at 566 K.
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高影响因子
Materials Today Physics
·
2020
·
IF 10.443
Y. Lu,Y. Qiu,K. Cai,X. Li,M. Gao,C. Jiang,J. He
The thermoelectric (TE) properties of organic/inorganic composite materials have been extensively studied for nearly one decade but there still has no significant breakthrough. Herein, we developed a facile method to prepare poly(3,4-ethylenedioxythiophene) (PEDOT)/Ag 2 Se/CuAgSe ternary composite films with ultrahigh performance and superior flexibility. First, PEDOT:poly(styrenesulfonate) (PSS)–coated Se (PC-Se) nanowires (NWs) were chemically in situ synthesized, then the PC-Se NWs were used as templates to prepare PEDOT:PSS coated Ag 2 Se/CuAgSe NWs, and finally highly flexible PEDOT/Ag 2 Se/CuAgSe ternary composite films on porous nylon membrane were fabricated by vacuum assisted filtration and then hot pressing. An optimized composite film with hierarchical microstructure defects shows a record power factor (PF) of ~1603 μW m −1 K −2 (corresponding 0.6 < ZT < 1.05) at 300 K, which is the record value for TE organic/inorganic composite materials. After bending for 1000 cycles around a 4-mm radius rod , about 92% of the initial PF is maintained, exhibiting an excellent flexibility, which is attributed to the synergetic effect of the flexible nylon membrane, the porous PEDOT/Ag 2 Se/CuAgSe film, and specifically the PEDOT as a binder. Moreover, a flexible TE module composed of 11 single-leg of the film generates a voltage of 45.8 mV and a maximum power of 3.2 μW (power density of 8.4 W m −2 ) at a temperature gradient of 36 K, verifying excellent TE properties of the film. This work provides a great idea for design and fabrication of high-performance flexible TE films, which can be extended to other chalcogenides/PEDOT composites and will certainly promote the development and application of TE organic/inorganic composite films.
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高影响因子
ACTA MATERIALIA
·
2021
·
IF 8.203
Jie Chen,Qiang Sun,Deyu Bao,Bang-Zhou Tian,Zegao Wang,Jun Tang,Dali Zhou,Lei Yang,Zhi-Gang Chen
Thermoelectric materials strengthened by defect engineering can also suffer from the compromise of plasticity, and in turn results in negative effect on the processability, reliability and durability of thermoelectric devices. Here, we introduce nano-twinned CuAgSe secondary phase to achieve simultaneously increased compressive strength and plasticity of the β-Ag 2 Se pellets without obviously sacrificing the thermoelectric performance, as evidenced by our thermoelectric measurements. Our pellet shows a maximum compressive strength of 96 MPa, which is ∼104% higher than that of pristine Ag 2 Se, ascribed to the impeded crack propagation by the CuAgSe secondary phase. An extraordinary deformation value of ∼19% is observed at the maximum compressive strength, which is attributed to the intrinsically large plastic deformation of the Ag 2 Se matrix, the deformable nano-twinned CuAgSe secondary as well as the interaction between the Ag 2 Se matrix and the CuAgSe secondary phase. This work indicates that introducing nano-twinned secondary phase in thermoelectric materials is a promising strategy for developing high-performance thermoelectric materials with high strength and plasticity.
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高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Xinxing Zhou,Kerui Li,Chengyi Hou,Qinghong Zhang,Yaogang Li,Hongzhi Wang
Exploring non-BiSbTe thermoelectric (TE) materials operable in the near room temperature range has emerged as a vibrant research frontier. However, the current synthesis of such materials heavily relies on energy-intensive techniques, with harsh conditions and the use of toxic reagents. In this work, a scalable, safe, simple, and cost-effective solution-based method is reported for synthesizing β -CuAgSe materials with a topologically dendritic structure. Notably, the synthesized material's surface is free from the complex organic ligands typically left by conventional synthesis methods, which mitigates the electrical performance degradation due to the intricate structure. Meanwhile, the multi-scale phonon scattering induced by the complex structure leads to a reduction in thermal conductivity. As a result, the material achieves a maximum ZT max of 0.48 at 298K and ZT ave of 0.42 in the 298–348K range, surpassing other doped CuAgSe materials and ranking among the top in various materials synthesized via solvothermal methods. The successful fabrication of thermoelectric devices (TED) enhanced with integrated radiative cooling and TE pastes formulated from these materials demonstrates their potential for applications in flexible TE.
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高影响因子
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