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1,342 results on '"Sun, Yiming"'

212. Reconfigurable Vertical Phototransistor with MoTe2Homojunction for High-Speed Rectifier and Multivalued Logical Circuits

Author

Deng, Qunrui, Zhao, Tu, Zhang, Jielian, Yue, Wenbo, Li, Ling, Li, Shasha, Zhu, Lingyu, Sun, Yiming, Pan, Yuan, Zheng, Tao, Liu, Xueting, Yan, Yong, and Huo, Nengjie

Abstract

The most reported two-dimensional (2D) reconfigurable multivalued logic (RMVL) devices primarily involve a planar configuration and carrier transport, which limits the high-density circuit integration and high-speed logic operation. In this work, the vertical transistors with reconfigurable MoTe2homojunction are developed for low-power, high-speed, multivalued logic circuits. Through top/bottom dual-gate modulation, the transistors can be configured into four modes: P-i-N, N-i-P, P-i-P, and N-i-N. The reconfigurable rectifying and photovoltaic behaviors are observed in P-i-N and N-i-P configurations, exhibiting ideal diode characteristics with a current rectification ratio over 105and sign-reversible photovoltaic response with a photoswitching ratio up to 7.44 × 105. Taking advantage of the seamless homogeneous integration and short vertical channel architecture, the transistor can operate as an electrical switch with an ultrafast speed of 680 ns, surpassing the conventional p-n diode. The MoTe2half-wave rectifier is then applied in high-frequency integrated circuits using both square wave and sinusoidal waveforms. By applying an electrical pulse with a 1/4 phase difference between two input signals, the RMVL circuit has been achieved. This work proposes a universal and reconfigurable vertical transistor, enabled by dual-gate electrostatic doping on top/bottom sides of MoTe2homojunction, suggesting a high integration device scheme for high-speed RMVL circuits and systems.

Published
2024
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214. Application of regional meteorology and air quality models based on the microprocessor without interlocked piped stages (MIPS) and LoongArch CPU platforms.

Author

Bai, Zehua, Wu, Qizhong, Cao, Kai, Sun, Yiming, and Cheng, Huaqiong

Subjects
AIR quality, STANDARD deviations, MICROPROCESSORS, CENTRAL processing units, METEOROLOGICAL research, METEOROLOGY, REDUCED instruction set computers
Abstract

The microprocessor without interlocked piped stages (MIPS) and LoongArch are reduced instruction set computing (RISC) processor architectures, which have advantages in terms of energy consumption and efficiency. There are few studies on the application of MIPS and LoongArch central processing units (CPUs) in geoscientific numerical models. In this study, the Loongson 3A4000 CPU platform with the MIPS64 architecture and the Loongson 3A6000 CPU platform with the LoongArch architecture were used to establish the runtime environment for the air quality modelling system Weather Research and Forecasting–Comprehensive Air Quality Model with extensions (WRF-CAMx) in the Beijing–Tianjin–Hebei region. The results show that the relative errors for the major species (NO 2 , SO 2 , O 3 , CO, PNO 3 , and PSO 4) between the MIPS and X86 benchmark platforms are within ± 0.1 %. The maximum mean absolute error (MAE) of major species ranged up to 10 -2 ppbV or µ g m -3 , the maximum root mean square error (RMSE) ranged up to 10 -1 ppbV or µ g m -3 , and the mean absolute percentage error (MAPE) remained within 0.5 %. The CAMx takes about 195 min on the Loongson 3A4000 CPU, 71 min on the Loongson 3A6000 CPU, and 66 min on the Intel Xeon E5-2697 v4 CPU, when simulating a 24 h case with four parallel processes using MPICH. As a result, the single-core computing capability of the Loongson 3A4000 CPU for the WRF-CAMx modelling system is about one-third of the Intel Xeon E5-2697 v4 CPU, and the one of Loongson 3A6000 CPU is slightly lower than that of Intel Xeon E5-2697 v4 CPU; but, the thermal design power (TDP) of Loongson 3A4000 is 40 W, while the TDP of Loongson 3A6000 is 38 W, only about one-fourth of that of Intel Xeon E5-2697 v4, whose TDP is 145 W. The results also verify the feasibility of cross-platform porting and the scientific usability of the ported model. This study provides a technical foundation for the porting and optimization of numerical models based on MIPS, LoongArch, or other RISC platforms. [ABSTRACT FROM AUTHOR]

Published
2024
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215. 2D Double Heterostructure Infrared Photodetector with Type‐III Band Alignment by Incorporating Bi2Se3 Layer.

Author

Ma, Jingyi, Chen, Shengdi, Zhao, Lei, Chen, Jianru, Lan, Zhibin, Yang, Mengmeng, Sun, Yiming, Zheng, Zhaoqiang, Gao, Wei, and Li, Jingbo

Subjects
QUANTUM efficiency, HETEROJUNCTIONS, PHOTODETECTORS, OPTOELECTRONICS, TRIBOELECTRICITY, TOPOLOGICAL insulators
Abstract

Two‐dimensional (2D) self‐powered photodetectors have attracted considerable attention due to their exceptional sensitivity, and low dark current. However, the poor responsivity of single heterojunctions with type‐III band alignment is primarily attributed to band‐to‐band tunneling. The implementation of a double heterojunction has the potential to enhance photovoltaic responsivity, enable broadband detection, and improve response speed. In this study, a back‐to‐back type‐III band alignment based on SnSe2/Bi2Se3/MoTe2 double heterostructure by dry transfer method is designed. As a result, it exhibited an impressive photovoltaic performance in the overlapping region. Achieving a maximum responsivity (R), external quantum efficiency (EQE), photoelectric conversion efficiency (PCE), and specific detectiviy (D*) of 493 mA W−1, 76 %, 3 % and 1.8 × 1011 Jones at a gate voltage (Vg) of 60 V under 808 nm illumination. It can be ascribed to the effective depletion region at the SnSe2/Bi2Se3 interface and the reversed band edge from depletion to accumulation mode at Bi2Se3/MoTe2 interface. In addition, a faster response speed of 553/583 µs and a lower dark current of 2.9 pA can be obtained. Moreover, this double heterostructure achieves better photovoltaic performance with Vg compared to the single MoTe2/SnSe2 heterojunction. These results demonstrates the potential as a candidate for back‐to‐back type‐III band alignment in low power optoelectronics. [ABSTRACT FROM AUTHOR]

Published
2024
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222. The fate of Sb(V) and As(V) during the aging of ferrihydrite

Author

Wu, Zhihao, primary, Zhao, Yao, additional, Zheng, Yan, additional, Yin, Mengxue, additional, Wang, Junhuan, additional, Bolan, Nanthi, additional, Fan, Feiyue, additional, Yun, Zhichao, additional, Zhou, Changzhi, additional, Yin, Hongliang, additional, Sun, Yiming, additional, Wang, Hailong, additional, Hou, Hong, additional, and Liu, Ruixia, additional

Published
2023
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