Article
Nanoscience & Nanotechnology
Wei Cao, Ziyu Wang, Ling Miao, Jing Shi, Rui Xiong
Summary: The high-temperature phase of Cu2Se, beta-Cu2Se, has attracted attention for its excellent thermoelectric efficiency. Studying the effect of strain and the possibility of n-type beta-Cu2Se is essential, with compressive strain promoting the power factor and tensile strain reducing lattice thermal conductivity. Predicted zT values for n-type and p-type beta-Cu2Se can reach 1.65 and 1.71 at 800 K respectively, and a feasible strategy to manipulate the lattice structure and carrier type is proposed through doping halogen elements.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Polymer Science
Minsu Kim, Dabin Park, Jooheon Kim
Summary: Sb2Se3 and beta-Cu2Se nanowires were successfully synthesized using hydrothermal reaction and water evaporation-induced self-assembly methods, with their morphologies confirmed using various analytical techniques. Coating the nanowires with polyaniline (PANI) improved their electrical conductivity, resulting in enhanced thermoelectric performance in flexible films. The combination of inorganic thermoelectric materials and flexible polymers showed promise in generating power for wearable or portable devices.
Article
Chemistry, Multidisciplinary
Congcong Xing, Yu Zhang, Ke Xiao, Xu Han, Yu Liu, Bingfei Nan, Maria Garcia Ramon, Khak Ho Lim, Junshan Li, Jordi Arbiol, Bed Poudel, Amin Nozariasbmarz, Wenjie Li, Maria Ibanez, Andreu Cabot
Summary: Cu2-xS and Cu2-xSe show promising thermoelectric properties for medium-temperature applications, while Cu2-xTe typically exhibits limited potential due to low Seebeck coefficients. To overcome this, Cu1.5-xTe-Cu2Se nanocomposites were investigated by consolidating surface-engineered Cu1.5Te nanocrystals. The surface engineering strategy allows for precise adjustment of Cu/Te ratios and results in a reversible phase transition, improving the thermoelectric properties. The addition of a layer of Cu2Se effectively inhibits grain growth and reduces thermal conductivity, resulting in a high dimensionless zT of 1.3 at 560 K.
Article
Chemistry, Multidisciplinary
Huijuan Zhao, Haihua Hu, Jing-Wei Li, Jing-Feng Li, Jing Zhu
Summary: Direct observation with atomic-scale resolution using spherical-aberration-corrected scanning transmission electron microscopy reveals a self-independent binary-sublattice construction in α-Cu2Se, with ordered copper fluctuation structures embedded in a rigid pseudo-cubic Se sublattice. The ordering of Cu results in considerable amounts of boundaries, leading to ultrastrong phonon scattering. Density functional theory calculations suggest that the electronic structures are mainly determined by the rigid Se sublattice and are not sensitive to various copper fluctuations. This study provides important information to understand the correlation between the specific structure and thermoelectric performance of α-Cu2Se, as well as for designing new thermoelectric materials.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Multidisciplinary Sciences
Zhifang Zhou, Yi Huang, Bin Wei, Yueyang Yang, Dehong Yu, Yunpeng Zheng, Dongsheng He, Wenyu Zhang, Mingchu Zou, Jin-Le Lan, Jiaqing He, Ce-Wen Nan, Yuan-Hua Lin
Summary: In this study, a fast preparation method of self-propagating high-temperature synthesis was used to realize in situ compositing of BiCuSeO and Cu2Se, optimizing the service stability of the thermoelectric materials. Additionally, the introduction of graphene in the composites improved the carrier mobility and reduced lattice thermal conductivity. The Cu2Se-BiCuSeO-graphene composites exhibited excellent thermoelectric properties.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Rui Ma, Delin Yang, Xinjian Li, Hongzhang Song, Yingjiu Zhang
Summary: Introducing the nanosecond phase into thermoelectric materials is an effective strategy to improve their thermoelectric properties. In this study, the influence of nano Y2O3 dispersion on the resistivity, Seebeck coefficient, and thermal conductivity of Cu2Se + x mol% Y2O3 was investigated. The results show that the nano Y2O3 dispersion can effectively scatter phonons and reduce thermal conductivity.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Multidisciplinary Sciences
Seungjun Choo, Faizan Ejaz, Hyejin Ju, Fredrick Kim, Jungsoo Lee, Seong Eun Yang, Gyeonghun Kim, Hangeul Kim, Seungki Jo, Seongheon Baek, Soyoung Cho, Keonkuk Kim, Ju-Young Kim, Sangjoon Ahn, Han Gi Chae, Beomjin Kwon, Jae Sung Son
Summary: This study presents a method of designing cellular thermoelectric architectures through 3D printing to achieve efficient and durable thermoelectric power generation. By optimizing the aspect ratio of thermoelectric legs and using mechanically stiff leg structures, power output can be increased and the durability of the power generation devices can be extended.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Lin Bo, Fujin Li, Yangbo Hou, Min Zuo, Degang Zhao
Summary: Forming co-alloying solid solutions is an effective strategy for improving thermoelectric performance. In this study, dense Cu2-x(MnFeNi)(x)Se samples with intrinsically low thermal conductivity were prepared, and the influences of nanostructure and compositional gradient on the microstructure and thermoelectric properties of Cu2Se were evaluated. The results showed a decrease in thermal conductivity and an increase in zT value for the Cu-1.91(MnFeNi)(0.09)Se sample.
Article
Nanoscience & Nanotechnology
Jian Zhang, Cheng Zhang, Ting Zhu, Yonggao Yan, Xianli Su, Xinfeng Tang
Summary: The mechanical properties and stability of Cu2Se compound at high temperatures were systematically investigated in this study, with the SHS-UT sample showing significantly improved mechanical properties and excellent thermal stability. The SHS-UT process effectively refined the grain size and increased grain boundary density, leading to enhanced compressive strength, bending strength, and Vickers hardness. Additionally, the compound prepared by SHS and ultrasonication demonstrated outstanding thermal stability at temperatures below 873 K, maintaining excellent thermoelectric performance with a ZT value exceeding 1.80.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Xiaomeng Cai, Huirong Jing, Hexige Wuliji, Hong Zhu
Summary: This work focuses on increasing the band degeneracy of Cu2Se through effective doping by analyzing the bonding characters and atomic energy levels in the compound. The study predicts that certain defects can converge the valence band maxima in Cu2Se, and first-principles electronic structure calculations are used to study the electrical transport properties of Cu2Se with different defects. The results suggest that weakened p-d orbital interaction may enhance the electrical transport properties in Cu2Se.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Wen Xie, Feng Liu, Yingxiang Zheng, Nina Ge, Bo Dai, Xiaowei Zhang
Summary: Cu2Se + x wt% CB4 composites were prepared by a hydrothermal method and hot-pressing technique. The electrical properties testing showed high power factor and suppressed thermal conductivity. CB4 could effectively improve the thermoelectric performance of Cu2Se.
Article
Nanoscience & Nanotechnology
Yao Lu, Xiang Li, Kefeng Cai, Mingyuan Gao, Wenyu Zhao, Jiaqing He, Ping Wei
Summary: In this study, a flexible PEDOT:PSS/Cu2Se-based nanocomposite film was prepared on a nylon membrane using vacuum filtration and hot pressing, demonstrating significantly improved thermoelectric properties. The optimized film showed a high power factor at 400K and excellent flexibility, retaining 85% of the power factor after 1000 bending cycles. Additionally, when paired with n-type PEDOT/Ag2Se/CuAgSe films, a flexible TE generator produced a maximum voltage and power output at a temperature difference of 44K.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Physics, Condensed Matter
Pengya Fan, Weizhou Hou, Lanwei Li, Shuyao Li, Jianli Wang, Zhenxiang Cheng, Chao Wang
Summary: Cu2Se samples doped with different concentrations of Ag2S were prepared, and the Ag and S elements diffused during the preparation process. AgCuSe impurity phase was observed in the doped samples, leading to a significant decrease in thermal conductivity. Additionally, the diffusion and substitution of S impeded the formation of Cu vacancies, and Ag ions filled the vacancies, resulting in a decrease in carrier concentration. Ultimately, the thermoelectric property was improved, achieving a maximum ZT value of approximately 1.5 at 820 K in Cu2Se/2% Ag2S, which was 1.5 times higher than the undoped Cu2Se sample.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Chemistry, Physical
Liangliang Yang, Jiangtao Wei, Yuanhao Qin, Lei Wei, Peishuai Song, Mingliang Zhang, Fuhua Yang, Xiaodong Wang
Summary: Thermoelectric technology offers advantages such as quiet operation, zero emissions, and long life, but its large-scale application is limited by the lower thermoelectric performance factor (ZT). By growing Cu2Se thin films using magnetron sputtering, researchers achieved high conductivity and ZT values. This work lays the foundation for further research on nano-thin-film thermoelectrics.
Article
Chemistry, Physical
Cagri Y. Oztan, Bejan Hamawandi, Yiqun Zhou, Sedat Ballikaya, Muhammet S. Toprak, Roger M. Leblanc, Victoria Coverstone, Emrah Celik
Summary: This research systematically doped stoichiometric Cu2Se compounds with gel-like Carbon Dots (CDs) and successfully enhanced the thermoelectric performance. The optimum doping ratio was found to be 2 wt%, resulting in a continuous enhancement of ZT to a maximum of 2.1.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Nanoscience & Nanotechnology
Yuan Zhu, Jia-sheng Liang, Xun Shi, Zhen Zhang
Summary: This study reports a flexible memristor based on Ag2S with a distinct interface resistance-switching mechanism. Compared to the filamentary mechanism, the interface resistance-switching has lower energy consumption and better stability under bending conditions. Image processing was also demonstrated using this new mechanism, showing significantly lower power consumption compared to the traditional filamentary mechanism.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Review
Chemistry, Multidisciplinary
Tian-Ran Wei, Pengfei Qiu, Kunpeng Zhao, Xun Shi, Lidong Chen
Summary: Ag(2)Q-based materials, such as silver chalcogenides, have complex crystal structures, high carrier mobility, low lattice thermal conductivity, and exceptional plasticity, making them potential thermoelectric materials. This review focuses on the latest advances in this material family, including the understanding of multi-scale structures and peculiar properties, the optimization of thermoelectric performance, and the rational design of new materials. The correlation between composition-phase structure and thermoelectric/mechanical properties is emphasized. Flexible and hetero-shaped thermoelectric prototypes based on Ag(2)Q materials are also demonstrated. Several key problems and challenges for further understanding and optimization of Ag(2)Q-based thermoelectric chalcogenides are proposed.
ADVANCED MATERIALS
(2023)
Article
Multidisciplinary Sciences
Qingyu Yang, Shiqi Yang, Pengfei Qiu, Liming Peng, Tian-Ran Wei, Zhen Zhang, Xun Shi, Lidong Chen
Summary: A series of high-performance p-type ductile thermoelectric materials based on silver sulfide-based ductile semiconductors has been developed, which show great potential for use in flexible thermoelectric devices. Thin and flexible pi-shaped devices with high power density have been successfully demonstrated.
Article
Chemistry, Physical
Xusheng Liu, Tong Xing, Pengfei Qiu, Tingting Deng, Peng Li, Xuewen Li, Xiaoya Li, Xun Shi
Summary: High zT and good mechanical properties are achieved for Bi2Te3-based alloys through hot extrusion, which refines the large grains and reduces the donor-like effect. The extruded polycrystalline Bi2Te2.79Se0.21 exhibits preferred orientation and high carrier mobility. The total thermal conductivity is decreased due to enhanced phonon scattering. This study provides a fast and low-cost technique to improve the TE and mechanical properties of commercial Bi2Te3 ingots at room temperature.
JOURNAL OF MATERIOMICS
(2023)
Article
Materials Science, Multidisciplinary
Yifang Huang, Jingdan Lei, Heyang Chen, Zhengyang Zhou, Hongliang Dong, Shiqi Yang, Haotian Gao, Tian -Ran Wei, Kunpeng Zhao, Xun Shi
Summary: Through the use of tantalum-sealing melting technique, high-quality pure alpha-MgAgSb with large grain size and less oxygen content was obtained. The as-synthesized tantalum-sealing melted alpha-MgAgSb exhibited intrinsically low thermal conductivity, large weighted mobility, and high carrier concentration. A maximum thermoelectric figure of merit zT value of 1.3 was achieved at around 500 K, and the average power factors and average zT values in the low-temperature range of (300 -550) K were as high as 25 mu W cm-1 K-2 and 1.1 respectively, ranking among the top values among known materials. This study provides new insights into the intrinsic properties of alpha-MgAgSb and demonstrates its great potential in harvesting low-grade waste heat.
Article
Materials Science, Multidisciplinary
Hong Su, Ping Lu, Chenxi Zhu, Wujie Qiu, Xianxiu Qiu, Kunpeng Zhao, Xiaoyue Lu, Yuyu Wei, Xun Shi, Lidong Chen, Fangfang Xu
Summary: High-performance thermoelectric Cu2Te1-xSx solid solutions can be formed over a wide compositional range despite the large atomic size difference between S and Te. The Cu sublattice exhibits partial order and even amorphous substructures in some compositions, while the S/Te sublattice is chemically disordered yet crystalline. The precise order-disorder configurations of the cation-anion sublattices and their evolution with compositional change remain unclear.
Article
Chemistry, Multidisciplinary
Qingyu Yang, Chen Ming, Pengfei Qiu, Zhengyang Zhou, Xianxiu Qiu, Zhiqiang Gao, Tingting Deng, Lidong Chen, Xun Shi
Summary: AgCuSe-based materials have been attracting attention in the field of thermoelectric (TE) recently due to their high electron mobility, low thermal conductivity, and abnormal brittle-ductile transition at room temperature. This study found that the crystal structure of AgCuSe-based materials is incommensurately modulated and has weak local lattice distortion. The delocalized and isotropic feature of Ag 5s states contributes to high carrier mobility, while the inhomogeneous, weak, and anisotropic Ag-Se bonds result in ultralow lattice thermal conductivity. Furthermore, alloying S in AgCuSe strengthens the interaction between adjacent Ag-Se layers, leading to a brittle-ductile transition at room temperature.
Article
Chemistry, Physical
Siyu Wang, Tong Xing, Tian-Ran Wei, Jiawei Zhang, Pengfei Qiu, Jie Xiao, Dudi Ren, Xun Shi, Lidong Chen
Summary: In this work, a series of Se-alloyed GeSb4Te7 compounds were synthesized and their structures and transport properties were systematically investigated. Raman analysis revealed that Se alloying introduced a new vibrational mode of GeSe2, enhancing the interatomic interaction forces and reducing the carrier concentration. Se alloying also increased the effective mass and improved the Seebeck coefficient of GeSb4Te7. The decrease in carrier concentration reduced the carrier thermal conductivity, resulting in optimized thermoelectric performance.
Article
Materials Science, Multidisciplinary
Yajun Wang, Zhi Long, Yao Cheng, Min Zhou, Hongyi Chen, Kunpeng Zhao, Xun Shi
Summary: In this study, the phase transition temperature of Cu2S was significantly suppressed by tuning the chemical bonding through Mn-doping. This led to the formation of a high-symmetry cubic phase with desirable thermoelectric properties at a much lower temperature regime. The weakened chemical bonding facilitated the formation of Cu vacancies and improved the hole concentrations for optimized electrical transports. Additionally, the lattice thermal conductivity was suppressed by reducing the sound velocity through lattice softening and enhancing phonon scattering by point defects. As a result, high average power factors of 6.13 mu W cm-1 K-2 and average zT values of 0.44 were achieved in the temperature range of 423 to 723 K, surpassing most Cu2S-based materials reported so far. This study demonstrates that chemical bonding engineering can serve as a scaffold for regulating the phase structures and transport properties in thermoelectric materials.
MATERIALS TODAY PHYSICS
(2023)
Article
Chemistry, Physical
Hexige Wuliji, Yupeng Ma, Heyang Chen, Tian-Ran Wei, Kunpeng Zhao, Yi-Yang Sun, Xun Shi
Summary: A dynamical approach is proposed to accurately describe the structure of Ag2S, a significant ductile semiconductor with promising thermoelectric and optoelectronic properties. The approach combines ab initio molecular dynamics simulation and density functional theory calculations, and successfully reproduces the experimental data.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Min Li, Hexige Wuliji, Zhengyang Zhou, Pengfei Qiu, Kunpeng Zhao, Xun Shi
Summary: As a typical liquid-like material, the argyrodite-type Ag9GaSe6 has attracted attention for its liquid-like characteristics, complex crystal structures, and high carrier mobility. By alloying Sn and Te into Ag9GaSe6, the electrical and thermal properties are optimized with a significantly improved Seebeck coefficient and greatly reduced lattice thermal conductivity. This leads to a boosted zT value of 1.4, representing a 75% improvement over pristine Ag9GaSe6.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
