Nanoscale
·
2018
·Vol. 10
·期 34
·15989-15997
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IF 7.233
Panpan Zhang,Fulai Zhao,Peng Long,Yu Wang,Yuchen Yue,Xuanyu Liu,Yiyu Feng,Rongjin Li,Wenping Hu,Yu Li,Wei Feng
We describe sonication-assisted liquid-phase exfoliation of rhombohedral germanium telluride (α-GeTe) to obtain a good dispersion of α-GeTe nanosheets in ethanol. The thickness of the α-GeTe nanosheets is dependent on the exfoliation conditions, and few-layer α-GeTe nanosheets of 2–4 layers and even monolayer α-GeTe were obtained. We use first-principles calculations to investigate the structural, electronic, and optical properties of monolayer and bulk α-GeTe and compare the optical band gap of centrifugally fractionated α-GeTe nanosheet dispersions with the computational predictions. We demonstrate that few layer α-GeTe nanosheets are purified selectively through centrifugation, and they exhibit high sensitivity to Fe3+. The scalable production of two-dimensional α-GeTe nanosheets can be used in the future optoelectronic industry.
研究领域:
材料科学
·
化学
·
物理学
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Ge Fu,Shangchao Lin,Yixuan Liu,Jie Xiao,Changying Zhao
GeTe thermoelectric materials are very promising for sustainable waste-heat harvesting, while optimizations have been focusing on lowering lattice thermal conductivity or decreasing carrier concentration. As a long-pursued strategy to improve electronic transport properties, the full realization of effective energy filtering has been hindered by the mismatch between the energy barriers introduced and the intrinsic Fermi level of the matrix material. In this work, a synergistic strategy combining modulated energy filtering effect and hierarchical defect evolution engineering leads to ultrahigh performance GeTe-based thermoelectric materials. Very effective energy filtering is achieved by incorporating carbon fibers, which increases the overall energy of charge carriers. This greatly enhances Seebeck coefficient to over 230 μ V K - 1 with minor reduction in electrical conductivity which simultaneously decreases electronic thermal conductivity. Furthermore, the inclusion of carbon fibers modulates the microstructure of GeTe and facilitates the evolution of point defects to higher dimensional defects for broadband phonon scattering, greatly suppressing the lattice thermal conductivity to 0.3 W m - 1 K - 1 . This strategy yields a prominent thermoelectric figure of merit ZT max ∼ 2.3 and an exceptional quality factor B max ∼ 2.24 for Ge 0.97 Bi 0.07 Te with 0.9 wt% carbon fibers. This study demonstrates a promising strategy to modulate the convoluted thermoelectric properties for ultrahigh performance thermoelectric materials.
研究领域:
材料科学
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能源技术
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DOI
高影响因子
Small
·
2026
·
IF 11.8
Yajun Wang,Xusheng Liu,Chengran Luo,Hongyi Chen,Zhenlong Huang,Peng Li,Binbin Jiang
Entropy engineering has emerged as an effective strategy for optimizing thermoelectric performance by decoupling electrical and thermal transport properties. By co-tuning the electronic band structure and phonon scattering mechanisms based on entropy and vacancy engineering, a high zT value of 2.62 at 700 K was achieved in GeTe-based materials. First, doping interstitial Cu atoms in Pb and Bi doped GeTe matrix has increased the carrier mobility and electrical properties by reducing the intrinsic Ge vacancies. Subsequently, introducing Sb at Ge sites will increase the average lattice symmetry based on entropy stabilized crystal structure, promoting the band convergence and the Seebeck coefficient due to the increased effective mass of density of states. The tuned Ge vacancies based on changing Sb content increased the electronic density of states, effectively suppressing the bipolar effect and achieving high power factor at the whole temperature range. Therefore, based on the entropy and vacancy co-tuning strategy, a high average zT of 1.8, along with a high experimental conversion efficiency of 13% with the fabricated segmented module were realized. This work provides an entropy and vacancy co-tuning strategy to systematically optimize the performance of thermoelectric power generation in a wide temperature range.
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DOI
PubMed
高影响因子
CHEMICAL PHYSICS LETTERS
·
2025
·
IF 3.1
Hongjie Bai,Yang-chun Bai,Ye-xin Gong,Guo-quan Ze,Ye Xiao,Zhengshang Wang
GeTe, a promising p-type thermoelectric material, faces challenges in scalability and stability due to complex compositions. We introduce a simplified strategy by incorporating minimal C 60
( ≤ 0.4 wt % ) into GeTe, leveraging interface mismatch to optimize electrical and thermal properties. C 60 reduces lattice thermal conductivity by ∼ 33% and enhances the Seebeck coefficient, achieving a power factor of ∼ 42 . 8 μ Wcm −1 K −2 . The GeTe-0.2 wt % C 60 C60 sample attains a maximum ZT of 2.15 at 773 K and an average ZT of 1.30 (323–773 K), surpassing comparable systems. This work highlights interface engineering for advancing thermoelectric materials and improving commercial viability.
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DOI
高影响因子
Journal of Materiomics
·
2025
·
IF 9.6
Fengting Mao,Zhongwei Zhang,Sijing Zhu,Chengyan Liu,Jie Gao,Jun-Liang Chen,Xiaoyang Wang,Tong Xing,Lei Miao
GeTe is a promising medium-temperature thermoelectric material. However, an excessively high concentration of Ge holes leads to a high hole carrier concentration, which can degrade its performance. Though carrier concentration reduction via doping has been pursued as a principal optimization approach, the strong interdependence between key transport parameters and carrier concentration severely limited the overall enhancement efficacy. In this work, a simple composite method is employed to achieve synergistic optimization of carrier concentration and carrier mobility, thereby increasing the power factor and reducing the lattice thermal conductivity. Sb and Fe form a core-shell structure, which effectively scatters phonons and reduces the lattice thermal conductivity, achieving a minimum value of 0.59 W⸱m –1 ⸱K –1 at 723 K. Additionally, Fe doping enhances the effective mass, improves the Seebeck coefficient, and significantly boosts the power factor, which reaches a peak value of 43.0 μW⸱cm –1 ⸱K –2 at 623 K. The results demonstrate that the sample Ge 0.885 Sb 0.1 Fe 0.015 Te achieves a maximum zT of approximately 2.13 at 723 K and an average zT ( zT avg ) of 1.43 within the temperature range of 323 K to 773 K. This work provides an effective path to enhance the performance of GeTe-based thermoelectric materials.
研究领域:
材料科学
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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
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Xiaobo Bai,Chengyan Liu,Fucong Li,Zhongwei Zhang,Ying Peng,Ruifan Si,Baoquan Feng,Guojing Wu,Jie Gao,Haiqiao Wei,Lei Miao
Lead-free GeTe-based thermoelectric (TE) materials are most promising candidates to replace the environmentally harmful PbTe for TE application at middle temperature range, where high power factor ( PF ) is significantly important for high power generation if the cost of heat source is low enough. In this study, we report for the first time that the PF of GeTe can be greatly enhanced by tailoring the interaction between Te 5s 2 lone pair and antibonding orbitals, which is induced by the hybridization of Zr 4d 2 electrons with antibonding orbitals. As a result, the contribution of Ge 4s 2 electrons to the valence band is promoted, leading to the band sharpening at the valence band maximum in rhombohedral phase, and simultaneous band sharpening at the valence band maximum and band flattening at the conduction band minimum in cubic phase. Lower band effective mass m b * effectively increases the carrier mobility to a very high value of ∼121 cm −2 V −1 s −1 (300 K), and the Seebeck coefficient is improved by the reduced detrimental effect of minority carrier in cubic phase, enhancing the maximum PF up to a record value of ∼5503 μW m −1 K −1 . With the assistance of reduced thermal conductivity, a peak zT of ∼1.9 is achieved at 673 K, which is one of the highest values among single doped GeTe. This work provides a new guidance to enhance the TE performance of GeTe-based materials.
研究领域:
材料科学
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物理学
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Tianbiao Zeng,Dong Feng,Qimeng Peng,Qi Liu,Guocui Xi,Gang Chen
Among the germanium-based compounds, GeTe is a promising anode candidate that exhibits high theoretical capacity (856 mAh g–1 vs Li+/Li and 401 mAh g–1 vs Na+/Na) and low volume expansion during an ion intercalation/deintercalation process. Nevertheless, achieving good dispersion of metal-like GeTe in anode materials remains a significant challenge. Herein, hybrid GeTe/graphene (GeTe/G) is proposed as a highly efficient anode for LiBs and SiBs by facile ball milling. Pulverized GeTe is effectively anchored on peeled graphene sheets that can accelerate Li+ transport in electrodes as predicted by theoretical calculations and thus result in improved overall electrochemical performance. For instance, GeTe/G possesses a high reversible capacity of 478 mAh g–1 under 0.1 A g–1 in the 300th cycle. Moreover, by further cross-linking the GeTe/G using carbon nanotube (CNT) and carbon nanofiber pyrolysis from cotton cellulose, the as-prepared three-dimensional (3D) flexible anode possesses macropores that acted as positive channels favorably for ion transport. Remarkably, the as-prepared flexible 3D GeTe/G/CNT electrode with a thickness of 1050 μm exhibits a high reversible capacity of 451.4 mAh g–1 (4.38 mAh cm–2) vs Li+/Li and 372.5 mAh g-1 (2.08 mAh cm-2) vs Na+/Na, respectively, in the second cycle under 0.1 A g–1. These results shed some light on the direct application of 3D flexible carbon sponge electrodes in high-performance LiBs/SiBs.
研究领域:
材料科学
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电化学
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产品关联
DOI
PubMed
高影响因子
Advanced Science
·
2025
·Vol. 12
·期 27
·2502832
·
IF 14.1
Kai-Yu Yang,Xiaoyuan Li,Yuanxin Jiang,Liangliang Wang,Kai Guo,Lei Miao,Junliang Chen,Jiye Zhang,Lin Li,Yusong Du,Guang-Hui Rao,Jun Luo,Jing-Tai Zhao
Segmentation is a widely adopted strategy to enhance the efficiency of medium- and high-temperature thermoelectric devices by capitalizing on the distinct properties of materials across various temperature ranges. Establishing a highly compatible matching relationship is crucial for maximizing conversion efficiency. In this study, the concepts of materials’ compatibility factor and relative current density into the screening process are emphasized for universal adaptability. The effectiveness and practicality of the theoretical model for optimal segmented combinations are validated through COMSOL finite element simulations and experimental results. A segmented thermoelectric power generation device is constructed that integrates the environmentally friendly n-type Mg 3 (Sb,Bi) 2 with the optimal segmented pairing of Bi 0.5 Sb 1.5 Te 3 -GeTe. Notably, at a temperature difference of Δ T = 440 K, this device achieves a maximum conversion efficiency of 10.4% and a peak output power of 0.41 W. These findings provide a solid theoretical foundation for the development of efficient combinations of thermoelectric materials.
研究领域:
材料科学
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能源工程
·
热电学
·
器件优化
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产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Zhengtang Cai,Yu Fang,Chun Ma,Kaipeng Zheng,Kang Lei,Shanming Ke,Renkui Zheng,Han Li
Excess intrinsic Ge vacancies in GeTe materials lead to excessively high hole concentration and high thermal conductivity, producing poor thermoelectric performance. Here, synergistic control and optimization of the thermoelectric transport properties and microstructure of GeTe-based materials were achieved through co-doping with In and rare earth element Y, resulting in a significant enhancement of thermoelectric performance. The Ge0.94In0.03Y0.03Te sample reached a ZTmax of 1.84 at 773 K, representing an increase of around 91% compared to the GeTe matrix. The experimental results indicate that the doping of In optimizes the band structure by introducing resonant levels and increasing the degeneracy of the valence band. Y doping introduces in situ nanoscale secondary phases and lattice distortions due to defect generation, enhancing phonon scattering and significantly reducing the κlat. This work elaborates on how co-doping with In and Y achieves the optimization of the thermoelectric performance of GeTe-based materials. While the electrical transmission characteristics are improved, the thermal conductivity is significantly reduced. For the Ge0.94In0.03Y0.03Te sample, κlat decreased to ∼0.56 W m–1 K–1 at 573 K, resulting in a ZTave of ∼0.99 over the entire temperature range, representing over 140% improvement compared to undoped GeTe. This improvement is significantly higher compared with other works on GeTe and PbTe.
研究领域:
材料科学
·
热电材料
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固体物理
·
能量转换材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）