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Your search keyword '"Zhu, Hao"' showing total 48 results
Start Over Author "Zhu, Hao" Publication Year Range Last 50 years Publisher iop publishing
48 results on '"Zhu, Hao"'

11. Steep-slope transistors enabled with 2D quantum coupling stacks.

Author

Raju, Parameswari, Zhu, Hao, Yang, Yafen, Zhang, Kai, Ioannou, Dimitris, and Li, Qiliang

Subjects
*DENSITY functional theory, *TOPOLOGICAL insulators, *TRANSISTORS
Abstract

As down scaling of transistors continues, there is a growing interest in developing steep-slope transistors with reduced subthreshold slope (SS) below the Boltzmann limit. In this work, we successfully fabricated steep-slope MoS2 transistors by incorporating a graphene layer, inserted in the gate stack. For our comprehensive study, we have applied density functional theory to simulate and calculate the change of SS effected by different 2D quantum materials, including graphene, germanene and 2D topological insulators, inserted within the gate dielectric. This theoretical study showed that graphene/MoS2 devices had steep SS (27.2 mV/decade), validating our experimental approach (49.2 mV/decade). Furthermore, the simulations demonstrated very steep SS (8.6 mV/decade) in WTe2/MoS2 devices. We conclude that appropriate combination of various 2D quantum materials for the gate-channel stacks, leads to steep SS and is an effective method to extend the scaling of transistors with exceptional performance. [ABSTRACT FROM AUTHOR]

Published
2023
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27. Performance improvement in p-Type WS2 field-effect transistors with 1T phase contacts.

Author

Yang, Yafen, Li, Han, Gu, Zhenghao, Chen, Lin, Zhu, Hao, Ji, Li, and Sun, Qingqing

Subjects
FIELD-effect transistors, INDIUM gallium zinc oxide, SCHOTTKY barrier, INJECTION wells, FERMI level, CHARGE carrier mobility, METAL oxide semiconductor field-effect transistors
Abstract

The non-ideal contact between the metal electrode and semiconducting channel has become one of the major bottlenecks degrading the performance of field-effect transistors (FETs) based on two-dimensional (2D) materials. The formation of the Schottky barrier prohibiting the carrier injection as well as the Fermi level pinning effect have a strong impact on the device performance. In this work, we fabricated a 2D WS2 FET device with engineered metallic 1T phase at the source/drain region by using Li intercalation method. As compared to the device with conventional 2H-WS2 channel, the engineered FET with a 2H-WS2/1T-WS2 junction has exhibited greatly improved performance such as over 10 times higher carrier mobility and steeper subthreshold slope. Such results have demonstrated the boosted carrier injection into the channel over the engineered metal contact as well as the reduced tunnel barrier width between the 2H/1T-WS2 junction. This can be attractive for the large-scale integration of the 2D devices towards high-performance and high-reproducibility nanoelectronics applications. [ABSTRACT FROM AUTHOR]

Published
2021
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28. Single boron atom anchored on graphitic carbon nitride nanosheet (B/g-C2N) as a photocatalyst for nitrogen fixation: A first-principles study.

Author

Zhu, Hao-Ran, Chen, Jia-Liang, and Wei, Shi-Hao

Subjects
*MOLECULAR orbitals, *NITRIDES, *ATOMS, *BORON, *BAND gaps, *NITROGEN fixation, *CATALYSTS, *PHOTOCATALYSTS
Abstract

It is essential to explore high efficient catalysts for nitrogen reduction in ammonia production. Based on the first-principles calculation, we find that B/g-C2N can serve as high performance photocatalyst in N2 fixation, where single boron atom is anchored on the g-C2N to form B/g-C2N. With the introduction of B atom to g-C2N, the energy gap reduces from 2.45 eV to 1.21 eV and shows strong absorption in the visible light region. In addition, N2 can be efficiently reduced on B/g-C2N through the enzymatic mechanism with low onset potential of 0.07 V and rate-determining barrier of 0.50 eV. The "acceptance-donation" interaction between B/g-C2N and N2 plays a key role to active N2, and the BN2 moiety of B/g-C2N acts as active and transportation center. The activity originates from the strong interaction between 1π1π* orbitals of N2 and molecular orbitals of B/g-C2N, the ionization of 1π orbital and the filling of 1π* orbital can increase the N≡N bond length greatly, making the activation of N2. Overall, this work demonstrates that B/g-C2N is a promising photocatalyst for N2 fixation. [ABSTRACT FROM AUTHOR]

Published
2021
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29. Research on Transformer Relay Protection System Based on Ubiquitous Power Grid Technology

Author

Huang Zhaoting, Wang Lei, Huang Li, Zhu Hao, Zhou Jinqiao, and Li Yan

Subjects
business.industry, Computer science, Electrical engineering, Cloud computing, Flow network, Grid, Telecommunications network, law.invention, Electric power system, Intelligent sensor, Relay, law, The Internet, business
Abstract

Things are ubiquitous power system as the core power, combined with intelligent sensor terminal, a communication network, the network flow system more complicated artificial intelligence technology and internet cloud configuration, having a holographic perception, ubiquitous connection, open sharing, innovative features fusion. Where the grid-based networking technology, system components paper analyses imprecision transformer relay fuzzy theory, a reliability model corresponding relay, and more truly reflect the reliability of the system.

Published
2020

34. Channel-protecting fabrication of top-gate MoS2 transistor arrays.

Author

Gu, Zhenghao, Liu, Hao, Wang, Yang, Zhu, Hao, Chen, Lin, Sun, Qingqing, and Zhang, David Wei

Subjects
TRANSISTORS, ATOMIC layer deposition, SURFACE passivation, THIN films, WATER vapor, TRANSITION metals
Abstract

The surface passivation on MoS2 and other transition metal dichalcogenides (TMDs) has been widely studied and utilized to prevent contamination and oxygen/water vapor penetration. Such approaches are mostly applied on the back-gate transistors after the formation of source/drain electrodes, while the compatibility in constructing top-gate devices has not yet been experimentally explored. Here, based on the large-area MoS2 thin film prepared with the atomic layer deposition technique, we developed an experimental routine to fabricate top-gate MoS2 thin-film transistor arrays with the TMD channel protected by high-k dielectric during the entire device fabrication process. The channel protection is enabled by the high-quality Al2O3 dielectric with proper pretreatment. The transistors in the array have shown enhanced electrical performance compared to the non-protected devices. Such a robust and well-controlled fabrication technique is a typical case of developing functional electronic devices by leveraging the strength of top-down lithography and the unique advantage of bottom-up growth, which can be further extended to the wide application in higher-level systems based on TMD materials. [ABSTRACT FROM AUTHOR]

Published
2020
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47. Additional Y3+ Doping Effect on Ferromagnetism of Ce0.97Co0.03 O2-? Compounds.

Author

Song Yuan, Zhang Huai, Wen Qi, Zhu Hao, and John Q. Xiao

Subjects
FERROMAGNETISM, ANTIFERROMAGNETISM, MAGNETISM, MATHEMATICAL physics
Abstract

Y3+ doping effect on magnetic properties of Ce0.97Co0.03 O2-d are examined. Vibrating sample magnetometer (VSM) measurements indicate that Ce0.97Co0.03 O2-d is ferromagnetic at room temperature. The saturated magnetization MS is altered by additional Y3+ doping, i.e., with the increase of the amount of Y3+ doping concentration in Ce0.97-yYyCo0.03 O2-d (y = 0.01, 0.05 and 0. 10), MS increases persistently. Raman spectra measurements indicate that additional oxygen vacancies are introduced with the amount of Y3+ doping content. The results can be well elucidated by the F-centre exchange coupling (FCE) mechanism proposed recently, thus they are important for understanding the ferromagnetism origination in transitional metal-doped insulating oxides. [ABSTRACT FROM AUTHOR]

Published
2008
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