Enhanced thermoelectric properties of Cu1.8Se1−S  alloys prepared by mechanical alloying and spark plasma sintering

Ji, Yi-Hong; Ge, Zhen‐Hua; Li, Zhi Dong; Feng, Jing

doi:10.1016/j.jallcom.2016.04.140

Cited by 20 publications

(24 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The phase transition from M-Cu 2 S (○) to H-Cu 2 S (●) stems from the more Te incorporated into the Cu 2 S matrix. Similar phase transformation has been reported in the Cu 1.8 S 1– x Se x system, in which the low-temperature H-Cu 1.8 S phase changes to the high-temperature cubic structure (C-Cu 1.8 S) in Cu 1.8 S 1– x Se x as Se content x ≥ 0.3 . As x increases to 0.3, phase separation of Cu 2 Te phase (☆) appears, which is clearer in the enlarged patterns at 23°–27°, as shown in Figure c.…”

Section: Results and Discussionsupporting

confidence: 82%

High Thermoelectric Figure of Merit Achieved in Cu₂S_1–xTe_x Alloys Synthesized by Mechanical Alloying and Spark Plasma Sintering

Yao

Zhang

Pei

et al. 2018

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

Chalcogenides have been considered as promising thermoelectric materials because of their low cost, nontoxicity, and environmental benignity. In this work, we synthesized a series of CuSTe (0 ≤ x ≤ 1) alloys by a facile, rapid method of mechanical alloying combined with spark plasma sintering process. The CuSTe system provides an excellent vision of the competition between pure phase and phase transformation, entropy-driven solid solution, and enthalpy-driven phase separation. When the Te concentration increases, the CuSTe system changed from the pure monoclinic CuS at x = 0 to monoclinic CuSTe solid solution at 0.02 ≤ x ≤ 0.06 and then transforms to hexagonal CuSTe solid solution at 0.08 ≤ x ≤ 0.1. The phase separation of hexagonal CuTe in the hexagonal CuS matrix occurs at 0.3 ≤ x ≤ 0.7 and finally forms the hexagonal CuTe at x = 1. Owing to the changed band structure and the coexisted CuS and CuTe phases, greatly enhanced power factor was achieved in all CuSTe (0< x < 1) alloys. Meanwhile, the point defect introduced by the substitution of Te/S atoms strengthened the phonon scattering, resulting in a lowered lattice thermal conductivity in most of these solid solutions. As a consequence, CuSTe exhibits a maximum ZT value of 1.18 at 723 K, which is about 3.7 and 14.8 times as compared to the values of pristine CuS (0.32) and CuTe (0.08), respectively.

show abstract

Section: Results and Discussionsupporting

confidence: 82%

High Thermoelectric Figure of Merit Achieved in Cu₂S_1–xTe_x Alloys Synthesized by Mechanical Alloying and Spark Plasma Sintering

Yao

Zhang

Pei

et al. 2018

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

show abstract

“…Recent studies show that synthesis route may dramatically influence and contribute to TE properties of nanomaterials [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. Among these methods, solvothermal, thermolysis [ 22 , 29 , 30 , 31 , 32 ] melting and annealing [ 24 , 26 , 33 , 34 ], mechanical alloying [ 35 , 36 , 37 ], co-precipitation and solution reduction [ 38 ], and microwave (MW)-assisted synthesis [ 14 , 32 , 39 ] have been reported in recent decades. MW-assisted synthesis has been reported for the synthesis of (BiSb) 2 (TeSe) 3 systems, where the produced quantities per batch have been rather limited.…”

Section: Introductionmentioning

confidence: 99%

“…We recently reported a high-throughput MW-assisted synthesis method that yielded Cu 2 Se with a very promising ZT of 2 [ 32 ]. In the MW synthesis, the reaction conditions, especially the temperature, pressure, and MW power, can be fully controlled, monitored, and tailored to the desired synthesis procedures [ 21 , 32 , 35 ], significantly differing from autoclave-based processes. In this work, we aim at demonstrating the process sensitivity of MW-assisted synthesis exemplified by Cu 1.8 Se and Cu 2 Se phases for obtaining highly efficient nanostructured TE materials.…”

Section: Introductionmentioning

confidence: 99%

Composition Tuning of Nanostructured Binary Copper Selenides through Rapid Chemical Synthesis and Their Thermoelectric Property Evaluation

et al. 2020

View full text Add to dashboard Cite

Reduced energy consumption and environmentally friendly, abundant constituents are gaining more attention for the synthesis of energy materials. A rapid, highly scalable, and process-temperature-sensitive solution synthesis route is demonstrated for the fabrication of thermoelectric (TE) Cu2−xSe. The process relies on readily available precursors and microwave-assisted thermolysis, which is sensitive to reaction conditions; yielding Cu1.8Se at 200 °C and Cu2Se at 250 °C within 6–8 min reaction time. Transmission electron microscopy (TEM) revealed crystalline nature of as-made particles with irregular truncated morphology, which exhibit a high phase purity as identified by X-ray powder diffraction (XRPD) analysis. Temperature-dependent transport properties were characterized via electrical conductivity, Seebeck coefficient, and thermal diffusivity measurements. Subsequent to spark plasma sintering, pure Cu1.8Se exhibited highly compacted and oriented grains that were similar in size in comparison to Cu2Se, which led to its high electrical and low thermal conductivity, reaching a very high power-factor (24 µW/K−2cm−1). Density-of-states (DOS) calculations confirm the observed trends in electronic properties of the material, where Cu-deficient phase exhibits metallic character. The TE figure of merit (ZT) was estimated for the materials, demonstrating an unprecedentedly high ZT at 875 K of 2.1 for Cu1.8Se sample, followed by 1.9 for Cu2Se. Synthetic and processing methods presented in this work enable large-scale production of TE materials and components for niche applications.

show abstract

“…The former could be achieved via carrier concentration optimization, 1,2 band structure tailoring, [3][4][5][6] modulation doping [7][8][9] etc., while the latter is usually realizable by nano-structuring 10,11 and/or constructing all-scale hierarchical architectures. [12][13][14] Meanwhile, thermoelectric systems with intrinsically low thermal conductivities, e.g., superionic Cu 2Àx Oh (Oh = Te, 15 Se 16 and S 17 ), partially filled skutterudites, 18 clathrates with caged frameworks, 19 Zintl phases with both covalent and ionic bonds, 20 layer-structured metal oxides 21,22 and materials with unbonded lone-pair valence electrons, 23,24 can provide another choice of achieving extraordinary ZT values.…”

Section: Introductionmentioning

confidence: 99%

Revisiting AgCrSe₂as a promising thermoelectric material

Huang

Feng

et al. 2016

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

We revisited and investigated a layer-structured thermoelectric material AgCrSe2, which has an extremely low thermal conductivity. After using both differential scanning calorimetry and a comparative laser flash method, we realized that the specific heat of this material, the main contributor to the reported low thermal conductivity, is unlikely to be way below the Dulong-Petit limit as revealed in the literature. Besides, our in situ X-ray diffraction pattern up to 873 K indicated the instability of AgCrSe2 over 723 K, where it begins to decompose into Cr2Se3 and Ag2Se. This unexpected decomposition phenomenon resulted in the gradual increment of specific heat and thermal diffusivity, hence the deterioration of the overall thermoelectric performance. We deliberately introduced Ag and Cr vacancies into the lattice for carrier concentration optimization and could achieve an optimal figure of merit of ZT ∼ 0.5 at 723 K in the nominal composition Ag0.96CrSe2 in the direction perpendicular to the sintering press. Our findings suggest that more thorough investigations are necessary to ensure that AgCrSe2 is a promising thermoelectric material.

show abstract

Enhanced thermoelectric properties of Cu1.8Se1−S alloys prepared by mechanical alloying and spark plasma sintering

Cited by 20 publications

References 19 publications

High Thermoelectric Figure of Merit Achieved in Cu₂S_1–xTe_x Alloys Synthesized by Mechanical Alloying and Spark Plasma Sintering

High Thermoelectric Figure of Merit Achieved in Cu₂S_1–xTe_x Alloys Synthesized by Mechanical Alloying and Spark Plasma Sintering

Composition Tuning of Nanostructured Binary Copper Selenides through Rapid Chemical Synthesis and Their Thermoelectric Property Evaluation

Revisiting AgCrSe₂as a promising thermoelectric material

Contact Info

Product

Resources

About

Enhanced thermoelectric properties of Cu1.8Se1−S alloys prepared by mechanical alloying and spark plasma sintering

Cited by 20 publications

References 19 publications

High Thermoelectric Figure of Merit Achieved in Cu2S1–xTex Alloys Synthesized by Mechanical Alloying and Spark Plasma Sintering

High Thermoelectric Figure of Merit Achieved in Cu2S1–xTex Alloys Synthesized by Mechanical Alloying and Spark Plasma Sintering

Composition Tuning of Nanostructured Binary Copper Selenides through Rapid Chemical Synthesis and Their Thermoelectric Property Evaluation

Revisiting AgCrSe2as a promising thermoelectric material

Contact Info

Product

Resources

About

High Thermoelectric Figure of Merit Achieved in Cu₂S_1–xTe_x Alloys Synthesized by Mechanical Alloying and Spark Plasma Sintering

High Thermoelectric Figure of Merit Achieved in Cu₂S_1–xTe_x Alloys Synthesized by Mechanical Alloying and Spark Plasma Sintering

Revisiting AgCrSe₂as a promising thermoelectric material