Nano Energy
·
2018
·
IF 13.12
Zhiwei Zhou,Junyou Yang,Qinghui Jiang,Xuesong Lin,Jiwu Xin,Abdul Basit,Jingdi Hou,Bingyang Sun
In this work, the co-doping in both the anion and cation sites of SnTe has been implemented by addition of BiCl 3 and the effect of co-doping on thermoelectric performance of SnTe-based materials has been studied detailedly. Benefitting from the sharp reduction of carrier concentration and the increase of density of states due to the electron donor contribution of Bi and Cl, the electrical transport properties have been improved greatly; moreover, the hierarchical architectures such as the point defects , dislocations, nano-particles and phase/grain boundaries act as multiscale phonon scattering centers and effectively suppress the transport of phonons in wide frequency range, thus reduced the thermal conductivity dramatically. Due to the synergistic regulation of cation-anion co-doping, a maximum ZT of ~1.27 at 873 K has been obtained in the sample of SnTe doping with 4% BiCl 3 , which enhances by 182% in comparison with the pristine sample.
研究领域:
材料科学
·
热电材料
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Meng Li,Jingxue Sun,Xin Zhou,Huaisuo Yao,Bowen Cong,Yingxuan Li,Gang Chen
The introduction of external magnetic field is one of the most widely studied strategies for photogenerated carrier separation in recent years. However, magnetic materials have great disadvantages in terms of photocatalytic performance. Semiconductor materials with magnetic properties are also extremely rare. It is extremely peculiar to research the magnetism of semiconductor photocatalyst triggered by vacancy. Here, the first example of ferromagnetic Bi 2 S 3 is achieved by controlled Bi vacancy (Bi 2 S 3 -V Bi ). The magnetism properties depends largely on the spin polarization of p electrons in S atoms, and its magnetic moment is mainly distributed on S atoms around cation vacancies. Under the induction of external magnetic field, the tunneling of spin-polarized electrons in S-2p orbital makes Bi 2 S 3 -V Bi have negative magnetoresistance effect. The ferromagnetic arrangement of Bi 2 S 3 -V Bi particles can reduce the resistivity and increase the tunneling of electrons. Meanwhile, Lorentz force generated by external magnetic field acts reversely on photogenerated electrons and holes, thus effectively inhibiting the recombination of carriers in photocatalyst. Moreover, the influence of Bi vacancy on Bi 2 S 3 magnetism is investigated by DFT calculation. This study provides a new strategy for effective carrier separation in photocatalysis .
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Yuyu Liu,Wenye Deng,Pengjun Zhao,Huimin Zhang,Aimin Chang,Yongxin Xie
The negative temperature coefficient (NTC) thermal sensor has received much attention for temperature sensing, which aims to achieve accurate temperature measurement by using the electrical signal generated by its temperature change. The perovskite (1- x )CaMn 0.05 Zr 0.95 O 3 - x CaMnO 3 ( x = 0, 0.1, and 0.2) composite ceramics were reported for the first time. Furthermore, their structure, microscopic morphology, and device performance were systematically evaluated. It was revealed that the sensor performance could be tuned by controlling the CaMnO 3 ratio in the low resistance phase. The phase structure and crystal structures (cell volume and cell parameters a, b, and c) of the composite ceramics were defined using x-ray diffraction (XRD) refinement. Scanning electron microscopy (SEM)/Mapping revealed dense and uniform micromorphology. The ln( ρ ) and 1000/T were quite linear, and the aging drift rate was as low as 1.89% after aging at 900 °C for 600 h. Importantly, a novel double hopping mechanism and a cation vacancy defect diffusion model were proposed to reveal the electron transport mechanism in the sensor lattice and elaborate the physical mechanism of the effect of cation vacancy defects on sensor resistance drift. In conclusion, this study prepared an NTC thermal sensor with ultra-high stability in a high temperature environment by rational design, providing a fresh idea for subsequently developing a high temperature NTC sensor.
研究领域:
材料科学
·
传感器技术
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Danqi He,Wenyu Zhao,Xin Mu,Hongyu Zhou,Ping Wei,Wanting Zhu,Xiaolei Nie,Xianli Su,Huijun Liu,Jiaqing He,Qingjie Zhang
How to optimize the thermoelectric performance of heavy-fermion systems remains a key challenge due to the extremely high thermal conductivity rooted in the extraordinarily high electrical conductivity . Here we report a new approach to simultaneously optimize the electron and phonon transport properties of heavy-fermion YbAl 3 by fabricating the multi-scale microstructures spanning from the atomic to nanometer to mesoscopic scales. We discover theoretically and experimentally that in YbAl 3 the nanostructures with less than 30 nm in size and atomic-scale dislocations and Yb vacancies can simultaneously scatter electron and phonon and thus significantly decrease the electrical conductivity and electronic thermal conductivity, while other hierarchical microstructures from the nanometer to mesoscopic scales can effectively scatter phonons and remarkably decrease the lattice thermal conductivity. The highest thermoelectric figure of merit ZT reaches 0.4 at 300 K and increased by 74%, which is a new record for un-doped YbAl 3 . Our work demonstrates that the electron and phonon transport properties of heavy-fermion system can be simultaneously enhanced by the multi-scale microstructures.
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
产品关联
DOI
高影响因子
Physica Status Solidi-Rapid Research Letters
·
2023
·Vol. 17
·期 12
·2300111
·
IF 2.8
Peizhuo Chen,Junhu Zhang,Guanzhong Zhou,Wenjing Zhai,Lin Lin,Zhibo Yan,Chao Chen,Xiangping Jiang,Chengliang Lu,Jun-Ming Liu
The anomalous transport phenomena and underlying mechanism of SrTiO 3 have been long term concerned, including the Kondo physics and anomalous Hall effects to be discussed herein. Nevertheless, a clarification of the physical origins for these phenomena and their intertransitions upon varying carrier density remain to be an issue, due to the limited modulation of carrier density. Herein, the intriguing transport behaviors of electrolyte-gated SrTiO 3 in the field-effect transistor geometry are investigated, which allows a relatively wide carrier density window. It is revealed that the remarkable Kondo-like resistance upturn, identified at relatively low carrier density, becomes gradually disappeared and replaced by the emerging nonlinear Hall resistance with increasing gating voltage, indicating the interesting gating-controlled transport behaviors. The detailed discussions on the underlying physics suggest that the gating-controlled transport can be well described by the multiband transport model taking into account magnetic scattering in the channel layer, a comprehensive scenario for the emergent transport effects in carrier-doped SrTiO 3 . The present work provides a promising platform for exploring novel quantum materials phenomena in SrTiO 3 and analogous systems.
研究领域:
凝聚态物理
·
材料科学
✓ 已验证
DOI
高影响因子
NANO LETTERS
·
2024
·
IF 9.6
Jiamiao Ni,Lin Cao,Boan Zhong,Quan Li,Chongxiao Guo,Jian Song,Yue Liu,Minghui Lu,Tongxiang Fan
Grain boundaries (GBs) and twin boundaries (TBs) in copper (Cu) are two major planar defects that influence electrical conductivity due to their complex electron transport characteristics, involving electron scattering and electron concentration. Understanding their local electronic states is crucial for the design of future conductor materials. In this study, we characterized electron behaviors at TBs and GBs within one Cu grain using atomic force microscopy. Our findings revealed that, compared with GBs, TBs exhibit better current transport capability (direct-current mode) and larger electromagnetic loss (high-frequency microwave mode). Both kelvin probe force microscopy and theoretical analysis suggested that TBs with smaller lattice disorder possess lower density of states at the Fermi level. The reduced density of states may result in decreased electron scattering and a lower electron concentration at TBs. The latter can be highlighted by the high-frequency skinning effect, manifested as larger electromagnetic loss and weaker high-frequency conductivity.
研究领域:
材料科学
·
凝聚态物理
·
电气工程
✓ 已验证
DOI
高影响因子
Nanoscale Research Letters
·
2019
·Vol. 14
·期 1
·1-6
·
IF 3.159
Shan Dan,Tong Guoqing,Cao Yunqing,Tang Mingjun,Xu Jun,Yu Linwei,Chen Kunji
Hybrid organic-inorganic perovskites (HOIPs) exhibit long electronic carrier diffusion length, high optical absorption coefficient, and impressive photovoltaic device performance. At the core of any optoelectronic device lie the charge transport properties, especially the microscopic mechanism of scattering, which must efficiently affect the device function. In this work, CH 3 NH 3 PbI 3 (MAPbI 3 ) films were fabricated by a vapor solution reaction method. Temperature-dependent Hall measurements were introduced to investigate the scattering mechanism in MAPbI 3 films. Two kinds of temperature-mobility behaviors were identified in different thermal treatment MAPbI 3 films, indicating different scattering mechanisms during the charge transport process in films. We found that the scattering mechanisms in MAPbI 3 films were mainly influenced by the decomposed PbI 2 components, which could be easily generated at the perovskite grain boundaries (GBs) by releasing the organic species after annealing at a proper temperature. The passivation effects of PbI 2 in MAPbI 3 films were investigated and further discussed with emphasis on the scattering mechanism in the charge transport process.
研究领域:
材料科学
·
凝聚态物理
·
半导体物理
·
光伏器件
·
纳米材料
·
表面与界面科学
·
功能材料
·
电子输运
✓ 已验证
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2023
·
IF 8.6
Chen Li,Ke Liu,Shang Peng,Qi Feng,Dequan Jiang,Ting Wen,Hong Xiao,Binbin Yue,Yonggang Wang
Temperature- or pressure-driven n–p conduction-type switching has been described as an emerging phenomenon for potential applications as transistors, switches, and memory devices. The key challenge in the development of such n–p conduction-type switching materials is to establish maneuverable and controllable methods to achieve easy convertibility and nonvolatility. Herein, we report the first example of rewritable pressure and temperature dual-controlled n–p conduction-type switching in marcasite-type CrSb2. At room temperature, CrSb2 exhibits an unexcepted pressure-driven n–p conductivity-type switching around 12 GPa accompanied by a marcasite-to-arsenopyrite structural transition and a semiconductor-to-metal transition. The dramatic conduction-type switching is irreversible after pressure releasing at room temperature but reversible by annealing at a relatively low temperature (>80 °C). Accordingly, a multicycle bistability switching process is established under the dual regulation of both pressure and temperature. The underlying structure–property mechanism is revealed by in situ/ex situ characterization and analyses of the atomic-level microstructure, local lattice distortion, and residual stress induced by compression. This demonstration provides a new platform for the rational design of rewritable temperature/pressure-responsive photoelectric conversion devices.
研究领域:
凝聚态物理
·
材料科学
·
功能材料
·
高压物理
·
电子输运
✓ 已验证
DOI
高影响因子
ACS Nano
·
2018
·
IF 13.709
Lei Fu,Debo Hu,Rafael G. Mendes,Mark H. Rümmeli,Qing Dai,Bin Wu,Lei Fu,Yunqi Liu
Platinum telluride (PtTe2), a member of metallic noble-transition-metal dichalcogenides (MNTMDs), has emerged as an indispensable candidate for superconducting, magnetic, and other electronic phase engineering, as well as optic applications. Herein, we report the van der Waals epitaxy of high-crystalline few-layer PtTe2 crystals on inert mica. Density functional theory calculations are used to illustrate a type-II Dirac cone along the Γ-A direction in the PtTe2 crystal. Impressively, the PtTe2 devices exhibit an extra-high electrical conductivity of 107 S m–1, 1000 times higher than that of metallic 1T MoS2. Meanwhile, the magnetoresistance effect at low temperatures reaches 800% in a field of 9.0 T. Furthermore, near-field nanooptical properties are assessed on PtTe2. Considering the subwavelength effect, the plasmonic wavelength λp ≈ 200 nm of 1T PtTe2 is obtained and the carrier concentration calculated from λp is about 1.22 × 1015 cm–2, which is 100-fold higher than that of MoTe2 in the previous reports. Therefore, our work demonstrates the growth of MNTMDs and provides insights into the plasmonic properties of 2D metallic telluride compounds.
研究领域:
凝聚态物理
·
材料科学
·
纳米光子学
·
电子输运
·
拓扑材料
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2015
·Vol. 4
·期 4
·857-862
·
IF 4.696
Xiwei Zhang,Jiansheng Jie,Xiujuan Zhang,Fengjun Yu
Au catalysts have been found to diffuse into semiconductor nanostructures and form non-radiative recombination centers during the synthesis process. This adverse impact is even more on the p-type doping of ZnSe nanostructures due to the self-compensation effect. Herein, low melt-point Bi was used as a catalyst for the synthesis of p-ZnSe nanowires via the VLS mechanism while the incorporation of Bi catalyst atoms causes effective p-type doping in the as-grown nanostructures. Top-gate MISFETs were fabricated to confirm the p-type conduction of Bi-catalyzed and doped ZnSeNWs. Temperature-dependent electrical measurements were used for understanding the charge transport mechanism and the doping effect of semiconductors. The thermal activation behavior of carriers is considered to dominate in the temperature range of 150–300 K while the 3D Mott VRH mechanism is considered to prevail over other mechanisms in the lower temperature range of 50–140 K.
研究领域:
纳米材料
·
半导体物理
·
电子输运
·
纳米电子学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2022
·Vol. 106
·期 5
·2911-2917
·
IF 4.186
Zhifang Zhou,Yunpeng Zheng,Yueyang Yang,Wenyu Zhang,Bin Wei,Mingchu Zou,Jinle Lan,Ce-Wen Nan,Yuan-Hua Lin
As a transparent thermoelectric oxide, gallium-doped zinc oxide (GZO) has the potential to power wearable or portable electronics and may be used in the integrated circuits industry for chip cooling. Constructing ZnO–GZO interfaces has been proposed as an effective strategy for improving thermoelectric performance of GZO thin films. However, without the aid of band structure calculation for multilayered films, it is hard to directly elucidate the underlying mechanisms of carrier transport. Weighted mobility is an indicator that reveals the inherent electronic transport properties like carrier scattering, electronic band structure, and so on. Thus, to further investigate the effects of ZnO–GZO interfaces on electrical properties of GZO thin films, the structures containing different numbers of ZnO–GZO interfaces were designed and the correlations among numbers of ZnO–GZO interfaces, weighted mobility, and electrical properties were explored. It was found that with more ZnO–GZO interfaces, the weighted mobility increased, and the power factor values also improved as well. Consequently, an enhanced power factor value reached 439 μW m −1 K −2 at 623 K. This work demonstrated the beneficial effects of multiple interfaces on the improvements of electrical transport performance through analyzing weighted mobility, which laid a foundation for further optimization of thermoelectric performance.
研究领域:
材料科学
·
热电学
·
薄膜技术
·
电子输运
✓ 已验证
DOI
高影响因子
PHYSICA B-CONDENSED MATTER
·
2023
·
IF 2.8
Jiafeng Chen,Jingying Si,Yifeng Zhang,Yanhong Chen,Rongrong Jia,Shixun Cao,Zhenjie Feng
NbTe 2 is a monoclinic quasi-two-dimensional layered semimetal . This paper reports the change of physical properties of NbTe 2 single crystals under the action of copper substitution. The zero-field ab -plane resistivity ρ xx shows that the samples havegood metallicity . Magnetoresistance changes of up to 23% were observed at a magnetic field of 13 T without any tendency to saturate. We have observed linear magnetoresistance under high magnetic field, which will be attributed to the linear band dispersion of small Fermi pockets. And we use a formula to describe the linear relationship: ρ = N i B π n 2 e c ∝ B . The curve of the Hall resistance changing with the magnetic field at the same temperature has a linear relationship with the magnetic field, and the slope is positive, which indicates that the carrier type is mainly hole-type carriers.
研究领域:
凝聚态物理
·
材料科学
·
电子输运
·
半金属
·
二维材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）