13 results on '"Zhu, Hongyu"'
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2. Facile synthesis and thermoelectric performance of BiCu1-xSeO
- Author
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Shuai Li, Zhu Hongyu, Su Taichao, Qingshan Liu, and Bingke Qin
- Subjects
Materials science ,Phonon scattering ,Phonon thermal conductivity ,business.industry ,Mechanical Engineering ,02 engineering and technology ,Power factor ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Thermoelectric materials ,01 natural sciences ,Crystallographic defect ,0104 chemical sciences ,Mechanics of Materials ,Vacancy defect ,High pressure ,Thermoelectric effect ,Optoelectronics ,General Materials Science ,0210 nano-technology ,business - Abstract
BiCuSeO based materials have been drawn much attention since they were found to be excellent thermoelectric materials recently. Apart from high performance, the time and energy-efficient synthesis of BiCuSeO is also essential for its commercialization. In this paper, a simple one-step high pressure method was used to quickly synthesize the copper-deficient BiCuSeO. The introduction of Cu vacancy improves the carrier concentration and power factor. Through the phonon scattering of fine grains and crystal defects caused by Cu deficiency and high pressure compression, an extremely low phonon thermal conductivity of BiCu0.94SeO ~ 0.3 Wm−1K−1 @ 750 K is obtained. An enhanced ZT ~ 0.87 at 750 K is obtained for BiCu0.94SeO. This value is twice higher than that of the original BiCuSeO, compared with the traditional time-consuming method.
- Published
- 2021
3. Hydrothermal synthesis and thermoelectric properties of PbS
- Author
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Meihua Hu, Shangsheng Li, Taichao Su, Haiyan Wang, Fan Haotian, Hongtao Li, He Zhang, and Zhu Hongyu
- Subjects
Materials science ,Mechanical Engineering ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,thermoelectric performance ,01 natural sciences ,0104 chemical sciences ,Nanomaterials ,high pressure ,Mechanics of Materials ,Thermoelectric effect ,TA401-492 ,Hydrothermal synthesis ,General Materials Science ,hydrothermal approach ,0210 nano-technology ,pbs ,Materials of engineering and construction. Mechanics of materials - Abstract
In this paper, hydrothermal approach combined with high pressure sintering method was employed to synthesize PbS. The X-ray diffraction results show that single phase PbS can be obtained by a simple hydrothermal method. The scanning electron microscope results show that the PbS sample has nearly cubic shape and preserves well crystallized and coarse grains after high pressure sintering. The thermoelectric performance of PbS obtained in this study is comparable to that of a PbS sample prepared by conventional method. The carrier type and concentration of PbS can be tuned effectively by doping with Bi. The maximum figure of merit for PbS doped with 1 mol% Bi reaches 0.44 at 550 K, which is about 30 % higher than that of undoped PbS. These results indicate that hydrothermal method provides a viable and controllable way of tuning the electrical transport and thermoelectric properties for PbS.
- Published
- 2016
4. Electrical transport and thermoelectric properties of Te–Se solid solutions.
- Author
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Yang, Manman, Zhu, Hongyu, Yi, Wencai, Li, Shangsheng, Hu, Meihua, Hu, Qiang, Du, Baoli, Liu, Xiaobing, and Su, Taichao
- Subjects
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SOLID solutions , *THERMOELECTRIC materials , *THERMAL conductivity , *SEEBECK coefficient , *HIGH temperatures , *DIFFUSION , *ALLOYS , *BAND gaps - Abstract
In this paper, p-type thermoelectric material Te–Se solid solutions have been successfully prepared by the high-pressure technique. The thermal conductivity of Te was depressed sharply by Se alloying. An extremely low thermal conductivity ∼0.27 W m−1 K−1 was obtained for Te alloyed with 15 mol% Se, which near the theoretical minimum, κ min. The bipolar diffusion effect of Te was suppressed by Se alloying due to the increased band gap, which lead to enhanced Seebeck coefficient and depressed bipolar diffusion thermal conductivity under high temperature. The maximum figure of merit, ZT of 0.37 at 480 K was obtained for Te alloyed with 5 mol% Se, which is about twice higher than that of pristine Te. • Thermoelectric Te–Se solid solutions were facile and fast prepared by one-step high-pressure technique. • The thermal conductivity of Te was depressed sharply and its Seebeck was improved at high temperatures by Se alloying. • An extremely low thermal conductivity ∼0.27 W m−1 K−1 was obtained for Te alloyed with 15 mol%. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
5. Thermoelectric properties of BiCuSO doped with Pb.
- Author
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Zhu, Hongyu, Su, Taichao, Li, Hongtao, Hu, Qiang, Li, Shangsheng, and Hu, Meihua
- Subjects
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THERMOELECTRICITY , *THERMAL conductivity , *ELECTRICAL resistivity , *BAND gaps , *HIGH pressure (Science) - Abstract
BiCuSeO based oxide show excellent thermoelectric performance due to its low thermal conductivity and moderate Power factor. There is rare study on the same crystal structured BiCuSO with lower cost and more earth abundance. The thermoelectric performance of BiCuSO is limited by its high resistivity result from its low carrier concentration and large band gap. In this paper, p-type polycrystalline BiCuSO doped with Pb was fast prepared by one-step high pressure method and the composition dependent thermoelectric properties was studied. The electrical resistivity and Seebeck coefficient of Bi 1-x Pb x CuSO both decreased monotonically with increasing Pb content due to the increased carrier concentration. The power factor was improved and the thermal conductivity was suppressed by Pb doping. The maximum figure of merit, ZT∼0.14 @ 700 K was obtained for the Bi 0.975 Pb 0.025 CuSO sample, which makes them promising candidates for thermoelectric applications. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
6. High pressure synthesis, structure and thermoelectric properties of BiCuChO (Ch = S, Se, Te).
- Author
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Zhu, Hongyu, Su, Taichao, Li, Hongtao, Pu, Chunying, Zhou, Dawei, Zhu, Pinwen, and Wang, Xin
- Subjects
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CERAMIC materials , *CHEMICAL synthesis , *STRUCTURAL analysis (Engineering) , *THERMOELECTRICITY , *X-ray diffraction , *CHALCOGENIDES - Abstract
Absract Bismuth copper oxychalcogenides, BiCuChO (Ch = S, Se, Te), are facile, and rapidly synthesized by high pressure method. The Rietveld refinement of powder X-ray diffractions shows that BiCuChO compounds have a layered crystal structure with a space group of P4/nmm. All the high pressure synthesised samples show semiconductor characteristics, while BiCuTeO prepared by the conventional method displays metal conducting behavior. The conducting behavior of BiCuTeO obtained in this study originates from the low crystal defect concentrations under the effects of high pressure; evidenced by density functional theory calculations. Large Seebeck coefficient ∼600 μV/K was obtained for BiCuSO, due to its high carrier effect mass. BiCuChO exhibits extremely low thermal conductivity (<1 Wm −1 K −1 ), which decreases with an increase in the Ch 2− ion radius. The maximum figure of merit reaches 0.03, 0.31 and 0.65 for BiCuSO, BiCuSeO and BiCuTeO, respectively, values which are comparable to those for samples prepared by the conventional, complex method. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
7. Electrical transport and thermoelectric properties of PbTe1−xIx synthesized by high pressure and high temperature.
- Author
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Yang, Manman, Zhu, Hongyu, Li, Hongtao, Su, Taichao, Hu, Qiang, Li, Shangsheng, Hu, Meihua, Du, Baoli, Ma, Hongan, and Jia, Xiaopeng
- Subjects
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THERMOELECTRIC materials , *THERMAL conductivity , *LEAD compounds , *HIGH temperatures , *HIGH pressure (Technology) , *DOPING agents (Chemistry) - Abstract
N-type thermoelectric materials PbTe doped with iodine (PbTe 1−x I x , x = 0.0001, 0.0003, 0.0007 and 0.001) were synthesized by high pressure and high temperature method (HPHT). Thermoelectric properties of PbTe 1−x I x are investigated in the range of 300–600 K. The carrier concentration of PbTe prepared by HPHT is more sensitive to I content compared to that of the PbTe 1−x I x sample prepared by other methods. The resistivities and the absolute values of Seebeck coefficients for PbTe 1−x I x increase while the thermal conductivities decrease with increasing temperature. A large power factor of 39.1 μW/(cmK 2 ) at room temperature is obtained with the carrier concentration of 9.7 × 10 18 cm −3 , which is much higher than that of Sb and Bi doped PbTe with the same synthesizing conditions. The high power factor is attributed to the high Hall mobility and large effective mass. The maximum figure-of-merit, ∼0.71 @ 600 K, is obtained for the samples with the carrier concentration of 9.7 × 10 18 cm −3 . [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
8. Effects of high pressure sintering on the microstructure and thermoelectric properties of BiCuSeO.
- Author
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Zhu, Hongyu, Li, Yan, Li, Hongtao, Su, Taichao, Pu, Chunying, Zhao, Yongsheng, Ma, Yanming, Zhu, Pinwen, and Wang, Xin
- Subjects
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BISMUTH compounds , *ELECTRIC properties of metals , *THERMAL properties of metals , *HIGH pressure (Technology) , *SINTERING , *METAL microstructure - Abstract
Polycrystalline BiCuSeO oxides are prepared by solid-state reaction followed by pressureless sintering (PLS) and high pressure sintering (HPS) methods. Both the experimental results and the density functional theory calculations indicate that the crystal defect concentrations of BiCuSeO can be reduced under the effect of high pressure. By comparing with the PLS sample, a larger power factor and a lower thermal conductivity can be obtained for the HPS sample. The maximum figure of merit ZT∼0.4 @ 800 K was obtained for the HPS sample, which is about 3 times higher than the PLS sample. These results indicate that the effect of high pressure is beneficial to modifying the microstructure and improving the thermoelectric performance of BiCuSeO oxyselenide. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
9. Hydrothermal synthesis and thermoelectric properties of PbS.
- Author
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Zhang, He, Wang, Haiyan, Zhu, Hongyu, Li, Hongtao, Su, Taichao, Li, Shangsheng, Hu, Meihua, and Fan, Haotian
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HYDROTHERMAL synthesis ,THERMOELECTRIC materials ,HIGH pressure (Technology) ,LEAD sulfide ,PHYSICS experiments - Published
- 2016
- Full Text
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10. Intrinsically low thermal conductivity of tetragonal-structured PbSe2.
- Author
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Zhu, Hongyu, Li, Yong, Yang, Xiaobing, Ma, Shuailing, and Su, Taichao
- Subjects
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THERMAL conductivity , *THERMOELECTRIC materials , *CARRIER density , *DENSITY functional theory - Abstract
Designing new compounds with earth-abundant constituent elements and intrinsically low thermal conductivity are crucial to the development of thermoelectric materials. In this letter, the tetragonal-structured PbSe 2 with extremely low thermal conductivity was prepared by two-step ball milling and high pressure synthesis method. Density functional theory calculation shows that the low thermal conductivity of PbSe 2 is originated from its weak interatomic bonding strength and high lattice vibration anharmonicity. We also found that the carrier concentration of PbSe 2 can be tuned effectively by Ag doping in Pb site, which leads to an enhanced figure of merit. These results indicate that PbSe 2 is a potential candidate as a thermoelectric material. • Tetragonal structured PbSe 2 was synthesized by a high-pressure method. • PbSe 2 behaves an extremal low thermal conductivity. • The carrier concentration and ZT of PbSe 2 was enhanced effectively by Ag doping. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
11. Composition-dependent transport properties of Ag1−x Pb18SbTe20 prepared by high pressure
- Author
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Su, Taichao, Zhu, Hongyu, Li, Hongtao, Li, Xiaolei, Li, Shangsheng, Deng, Le, Zheng, Shizao, Ma, Hongan, and Jia, Xiaopeng
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HIGH pressure chemistry , *STOICHIOMETRY , *THERMOELECTRIC materials , *TEMPERATURE effect , *ELECTRIC power factor , *SILVER compounds , *TRANSPORT theory , *CHEMICAL processes - Abstract
Abstract: Non-stoichiometric Ag1−x Pb18SbTe20 (x =0, 0.2, 0.5, 0.7, 0.85) thermoelectric materials were prepared by high pressure method. The composition-dependent transport properties were studied at room temperature. The measurement results show that the carrier concentration and hall mobility of AgPb18SbTe20 could be tuned effectively by adjusting the content of Ag. The Seebeck coefficient and resistivity decrease with an increase of x. The maximum power factor of 2.3×10−3 Wm−1 K−2 is obtained at x =0.7, which is about 76% higher than that of the sample with stoichiometric composition. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
12. Facile synthesis and thermoelectric performance of BiCu1-xSeO.
- Author
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Zhu, Hongyu, Liu, Qingshan, Li, Shuai, Qin, Bingke, and Su, Taichao
- Subjects
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CRYSTAL defects , *CARRIER density , *THERMAL conductivity , *THERMOELECTRIC materials , *PHONONS , *PHONON scattering - Abstract
• Thermoelectric oxide BiCuSeO was facile prepared by one-step high-pressure method. • The sample contains fine grains and a large number of multiscale nanoparticles. • An extremely low thermal conductivity and enhanced ZT of BiCuSeO was obtained. BiCuSeO based materials have been drawn much attention since they were found to be excellent thermoelectric materials recently. Apart from high performance, the time and energy-efficient synthesis of BiCuSeO is also essential for its commercialization. In this paper, a simple one-step high pressure method was used to quickly synthesize the copper-deficient BiCuSeO. The introduction of Cu vacancy improves the carrier concentration and power factor. Through the phonon scattering of fine grains and crystal defects caused by Cu deficiency and high pressure compression, an extremely low phonon thermal conductivity of BiCu 0.94 SeO ~ 0.3 Wm−1K−1 @ 750 K is obtained. An enhanced ZT ~ 0.87 at 750 K is obtained for BiCu 0.94 SeO. This value is twice higher than that of the original BiCuSeO, compared with the traditional time-consuming method. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
13. Facile synthesize and enhanced thermoelectric performance of PbS with Cl doping and PbSe alloying.
- Author
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Shao, Kuijia, Zhou, Dawei, Yang, Mengxiang, Zhu, Hongyu, Fan, Haotian, and Su, Taichao
- Subjects
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CARRIER density , *THERMAL conductivity , *LEAD sulfide , *ALLOYS , *THERMOELECTRIC materials , *HIGH temperatures , *MECHANICAL alloying - Abstract
Besides inferior conversion efficiency, the widespread application of thermoelectric materials currently faces the challenges of the rare and high cost of constituent elements, complex and time-consuming synthesis. Therefore, it is urgent to develop facile synthesized methods and high-performance thermoelectric materials consisting of elements with earth-abundance and low cost. Meeting above partial requirement, lead sulfide (PbS) recently was identified as a potential thermoelectric material to substitute current commercial PbTe. In this paper, a one-step high-pressure method was employed to facile and fast synthesis of PbS. Trace Cl doping tunes the carrier concentration of PbS effectively, which optimizes the electrical transport properties. Further PbSe alloying sharply reduces the thermal conductivity of PbS. Therefore, an enhanced zT ∼1.0 @ 700 K was obtained for PbS doped with 0.3 at% Cl and alloyed with 25 at% PbSe, which is comparable to the commercially applied PbTe. These results indicate that high-pressure combing with Cl-doping and PbSe-alloying provide a facile method and strategy to fabricate high-performance PbS-based thermoelectric materials. • Earth-abundant and low-cost thermoelectric compound PbS was facile and fast synthesized by one-step high pressure method. • Cl doping modulates the carrier concentration of PbS and thus optimizes its electrical properties at high temperature. • The chemical bond of PbS was weaken by PbSe alloying, which induces an enhanced Hall mobility near room temperature. • The thermal conductivity of PbS was suppressed sharply by PbSe alloying. • The enhanced zT max and zT avg achieve to 1.0 and 0.67 for PbS 0.747 Cl 0.003 Se 0.25 and PbS 0.497 Cl 0.003 Se 0.5, respectively [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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