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Your search keyword '"Xu, Yongshan"' showing total 128 results
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128 results on '"Xu, Yongshan"'

18. Scalable integration of hybrid high-κdielectric materials on two-dimensional semiconductors

Author

Xu, Yongshan, Liu, Teng, Liu, Kailang, Zhao, Yinghe, Liu, Lei, Li, Penghui, Nie, Anmin, Liu, Lixin, Yu, Jun, Feng, Xin, Zhuge, Fuwei, Li, Huiqiao, Wang, Xinran, and Zhai, Tianyou

Abstract

Two-dimensional (2D) semiconductors are promising channel materials for next-generation field-effect transistors (FETs). However, it remains challenging to integrate ultrathin and uniform high-κdielectrics on 2D semiconductors to fabricate FETs with large gate capacitance. We report a versatile two-step approach to integrating high-quality dielectric film with sub-1 nm equivalent oxide thickness (EOT) on 2D semiconductors. Inorganic molecular crystal Sb2O3is homogeneously deposited on 2D semiconductors as a buffer layer, which forms a high-quality oxide-to-semiconductor interface and offers a highly hydrophilic surface, enabling the integration of high-κdielectrics via atomic layer deposition. Using this approach, we can fabricate monolayer molybdenum disulfide-based FETs with the thinnest EOT (0.67 nm). The transistors exhibit an on/off ratio of over 106using an ultra-low operating voltage of 0.4 V, achieving unprecedently high gating efficiency. Our results may pave the way for the application of 2D materials in low-power ultrascaling electronics.

Published
2023
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25. Giant Tunability of Charge Transport in 2D Inorganic Molecular Crystals by Pressure Engineering.

Author

Feng, Xin, Bu, Kejun, Liu, Teng, Guo, Songhao, Sun, Zongdong, Fu, Tonghuan, Xu, Yongshan, Liu, Kailang, Yang, Sijie, Zhao, Yinghe, Li, Huiqiao, Lü, Xujie, and Zhai, Tianyou

Subjects
MOLECULAR crystals, VAN der Waals forces, BAND gaps
Abstract

The unique intermolecular van der Waals force in emerging two‐dimensional inorganic molecular crystals (2DIMCs) endows them with highly tunable structures and properties upon applying external stimuli. Using high pressure to modulate the intermolecular bonding, here we reveal the highly tunable charge transport behavior in 2DIMCs for the first time, from an insulator to a semiconductor. As pressure increases, 2D α‐Sb2O3 molecular crystal undergoes three isostructural transitions, and the intermolecular bonding enhances gradually, which results in a considerably decreased band gap by 25 % and a greatly enhanced charge transport. Impressively, the in situ resistivity measurement of the α‐Sb2O3 flake shows a sharp drop by 5 orders of magnitude in 0–3.2 GPa. This work sheds new light on the manipulation of charge transport in 2DIMCs and is of great significance for promoting the fundamental understanding and potential applications of 2DIMCs in advanced modern technologies. [ABSTRACT FROM AUTHOR]

Published
2023
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29. Comparison of Success Rate and Complications of Totally Percutaneous Decannulation in Patients With Veno-Arterial Extracorporeal Membrane Oxygenation and Endovascular Aneurysm Repair

Author

Liu, Zhenjie, primary, Xu, Yongshan, additional, Xu, Xin, additional, He, Minzhi, additional, Han, Pan, additional, Shao, Changming, additional, Pan, Yifeng, additional, Zhang, Libin, additional, Yin, Li, additional, Li, Zhenhua, additional, Huang, Man, additional, and Chen, Bing, additional

Published
2021
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31. The Diagnostic Criteria of Refeeding Syndrome in Critically Ill Patients from four Chinese Hospitals: A Multicenter Prospective Study

Author

Lu, Kongmiao, primary, Shen, Xuping, additional, Zheng, Xiangxin, additional, Xu, Xin, additional, Xu, Zhijun, additional, Xu, Yongshan, additional, Hu, Yanting, additional, Wu, Yunlong, additional, Luo, Jinming, additional, Yan, Biqing, additional, Han, Wei, additional, Chen, Xiaomeng, additional, Wan, Huqiang, additional, Wang, Qianwen, additional, Wang, Huijuan, additional, Zhang, Hui, additional, Shao, Feifei, additional, Tao, Jing, additional, Gai, Lei, additional, and Huang, Man, additional

Published
2021
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43. Van der Waals heterostructure of Bi2O2Se/MoTe2for high-performance multifunctional devices

Author

Sun, Li, Xu, Yongshan, Yin, Tingting, Wan, Rui, Ma, Yanan, Su, Jun, Zhang, Zhi, Liu, Nishuang, Li, Luying, Zhai, Tianyou, and Gao, Yihua

Abstract

Two-dimensional van der Waals heterostructures exhibit distinctive electronic and optoelectronic properties, making them promising structures for constructing advanced multifunctional devices. However, devices based on conventional charge-carrier transport mechanisms often perform only a single function, which limits its integration and performance. Here, we present a vertical van der Waals heterostructure made of Bi2O2Se and MoTe2, allowing it to act as high-performance backward diode, forward diode, photodetector and photovoltaic device at various working conditions. The applications are enabled by band-alignment switching between p–n heterostructure controlled by minority carrier diffusion and n–n heterostructure governed by the thermionic emission and tunneling-mediated processes. As a backward diode, the device displays a high reverse rectification ratio of 5.0 × 104. As a photodetector, the device demonstrates a broad spectral photoresponse ranging from ultraviolet (365 nm) to near-infrared (1050 nm). When irradiated by 532 nm laser, the photodetector shows a responsivity of up to 11.6 A/W and achieves quick response/recovery speed of 19.6/8.8 μs. As a photovoltaics device, an external quantum efficiency of 78% and a responsivity of 0.33 A/W are observed. This study showcases the potential for high-performance multifunctional devices utilizing Bi2O2Se/MoTe2heterostructures and provides comprehensive insights into the designed band alignment and its applications.

Published
2024
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44. MoS2 Van der Waals p–n Junctions Enabling Highly Selective Room‐Temperature NO2 Sensor.

Author

Zheng, Wei, Xu, Yongshan, Zheng, Lingli, Yang, Chen, Pinna, Nicola, Liu, Xianghong, and Zhang, Jun

Subjects
*CHEMICAL vapor deposition, *ELECTRONIC equipment, *DETECTORS, *N-type semiconductors, *ELECTROCHEMICAL sensors, *THIN films, *ELECTRIC conductivity, *ULTRAVIOLET detectors
Abstract

Van der Waals p–n junctions of 2D materials present great potential for electronic devices due to the fascinating properties at the junction interface. In this work, an efficient gas sensor based on planar 2D van der Waals junctions is reported by stacking n‐type and p‐type atomically thin MoS2 films, which are synthesized by chemical vapor deposition (CVD) and soft‐chemistry route, respectively. The electrical conductivity of the van der Waals p–n junctions is found to be strongly affected by the exposure to NO2 at room temperature (RT). The MoS2 p–n junction sensor exhibits an outstanding sensitivity and selectivity to NO2 at RT, which are unavailable in sensors based on individual n‐type or p‐type MoS2. The sensitivity of 20 ppm NO2 is improved by 60 times compared to a p‐type MoS2 sensor, and an extremely low limit of detection of 8 ppb is obtained under ultraviolet irradiation. Complete and very fast sensor recovery is achieved within 30 s. These results are superior to most of the previous reports related to NO2 detection. This work establishes an entirely new sensing platform and proves the feasibility of using such materials for the high‐performance detection of gaseous molecules at RT. [ABSTRACT FROM AUTHOR]

Published
2020
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46. Susceptible CoSnO3 nanoboxes with p-type response for triethylamine detection at low temperature.

Author

Zheng, Lingli, Zhao, Yingqiang, Xu, Yongshan, Yang, Chen, Zhang, Jun, and Liu, Xianghong

Subjects
LOW temperatures, X-ray photoelectron spectroscopy, ETHYLAMINES, TRANSMISSION electron microscopy, METALLIC oxides, CHEMICAL structure
Abstract

Ternary metal oxides containing two different metal cations are highly promising candidates for sensor materials due to their intriguing properties. Herein, we report on the application of CoSnO3 nanoboxes with a porous structure as a sensing layer for highly sensitive detection of triethylamine at a relatively low temperature. The CoSnO3 nanoboxes are obtained by calcination of CoSn(OH)6 precursors derived from a solution precipitation method. The dosage of cobalt is found to strongly influence the structure of the products and the sensing properties. The morphological structure and chemical composition of the materials are investigated in detail by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N2 adsorption–desorption and X-ray photoelectron spectroscopy. Gas sensing measurements demonstrate that the CoSnO3 nanoboxes exhibit a p-type response and can efficiently detect triethylamine at a low temperature of 100 °C with a limit of detection of 134 ppb. The gas sensing mechanism is discussed by the modulation of a hole accumulation layer (HAL) on the adsorption of gas molecules. [ABSTRACT FROM AUTHOR]

Published
2020
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