GuanHua Chen

ORCID: 0000-0001-5015-0902
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About
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Research Areas
  • Quantum and electron transport phenomena
  • Molecular Junctions and Nanostructures
  • Spectroscopy and Quantum Chemical Studies
  • Graphene research and applications
  • Advanced Chemical Physics Studies
  • Machine Learning in Materials Science
  • Advancements in Semiconductor Devices and Circuit Design
  • Carbon Nanotubes in Composites
  • Semiconductor materials and devices
  • Computational Drug Discovery Methods
  • Advanced Battery Materials and Technologies
  • Photochemistry and Electron Transfer Studies
  • Advancements in Battery Materials
  • Mechanical and Optical Resonators
  • X-ray Diffraction in Crystallography
  • Chemical Thermodynamics and Molecular Structure
  • Nonlinear Optical Materials Research
  • Advanced Battery Technologies Research
  • Electrocatalysts for Energy Conversion
  • Ferroelectric and Negative Capacitance Devices
  • Crystallization and Solubility Studies
  • Advanced battery technologies research
  • Laser-Plasma Interactions and Diagnostics
  • Ion-surface interactions and analysis
  • Nanowire Synthesis and Applications

University of Hong Kong
2016-2025

QuantumCTek (China)
2021-2025

Chinese University of Hong Kong
2005-2025

Guangdong Ocean University
2024

National Taiwan University
2022-2024

Nantong University
2024

China Academy of Engineering Physics
2022-2024

Hong Kong Observatory
2023-2024

Concord Consortium
2020

University of Miami
2016-2018

Abstract Interfacial dynamics within chemical systems such as electron and ion transport processes have relevance in the rational optimization of electrochemical energy storage materials devices. Evolving understanding fundamental electrochemistry at interfaces would also help relevant phenomena biological, microbial, pharmaceutical, electronic, photonic systems. In lithium‐ion batteries, instability electrolyte its ensuing reactive decomposition proceeds anode surface Helmholtz double layer...

10.1002/aenm.202203307 article EN cc-by-nc-nd Advanced Energy Materials 2023-01-18

Nickel-rich layered oxides (NLOs) are considered as one of the most promising cathode materials for next-generation high-energy lithium-ion batteries (LIBs), yet their practical applications currently challenged by unsatisfactory cyclability and reliability owing to inherent interfacial structural instability. Herein, we demonstrate an approach reverse unstable nature NLOs through surface solid reaction, which reconstructed lattice turns stable robust against both side reactions...

10.1021/jacs.2c13787 article EN Journal of the American Chemical Society 2023-03-24

Abstract The design of high‐entropy single‐atom catalysts (HESAC) with 5.2 times higher entropy compared to (SAC) is proposed, by using four different metals (FeCoNiRu‐HESAC) for oxygen reduction reaction (ORR). Fe active sites intermetallic distances 6.1 Å exhibit a low ORR overpotential 0.44 V, which originates from weakening the adsorption OH intermediates. Based on density functional theory (DFT) findings, FeCoNiRu‐HESAC nitrogen‐doped sample were synthesized. atomic structures are...

10.1002/advs.202309883 article EN Advanced Science 2024-04-30

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTValence-Bond Charge-Transfer Model for Nonlinear Optical Properties of Organic MoleculesDaqi Lu, Guanhua Chen, Joseph W. Perry, and William A. Goddard IIICite this: J. Am. Chem. Soc. 1994, 116, 23, 10679–10685Publication Date (Print):November 1, 1994Publication History Published online1 May 2002Published inissue 1 November 1994https://pubs.acs.org/doi/10.1021/ja00102a037https://doi.org/10.1021/ja00102a037research-articleACS PublicationsRequest...

10.1021/ja00102a037 article EN Journal of the American Chemical Society 1994-11-01

By introducing the self-energy density functionals for dissipative interactions between reduced system and its environment, we develop a time-dependent density-functional theory formalism based on an equation of motion Kohn-Sham single-electron matrix system. Two approximate schemes are proposed functionals, complete second order approximation wide-band limit approximation. A numerical method is subsequently developed implemented to simulate steady transient current through various realistic...

10.1103/physrevb.75.195127 article EN Physical Review B 2007-05-24

We apply the machine learning (ML) tool to calculate Gibbs free energy (ΔG) of reaction intermediates rapidly and accurately as a guide for designing porphyrin- graphene-supported single-atom catalysts (SACs) toward electrochemical reactions. Based on 2105 DFT calculation data from literature, we trained support vector (SVR) algorithm. The hyperparameters were optimized using Bayesian optimization along with 10-fold cross-validation avoid overfitting. Shapley Additive exPlanation (SHAP)...

10.1021/acs.jpcc.3c00765 article EN The Journal of Physical Chemistry C 2023-05-19

A quantum-mechanical simulation is carried out to investigate the charge distribution and electrostatic potential along a $1\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$ long (5,5) single-walled carbon nanotube under realistic field-emission experimental conditions. single layer of atoms found sufficient shield most electric field except at tip where strong penetration occurs. The leads nonlinear decrease barrier for emission, which equally responsible low threshold voltage besides well-known...

10.1103/physrevlett.92.106803 article EN Physical Review Letters 2004-03-12

Graphene nanoribbon junction based electronic devices are proposed in this letter. Nonequilibrium Green’s function calculations show that junctions tailored from single layer graphene with different edge shapes and widths can act as metal/semiconductor quantum dots be implemented. In virtue of the possibilities patterning monolayer down to atomic precision, these structures, quite previously reported two-dimensional bulk or carbon nanotube devices, expected used building blocks future...

10.1063/1.2745268 article EN Applied Physics Letters 2007-05-28

Based on our earlier works [X. Zheng et al., Phys. Rev. B 75, 195127 (2007); J. S. Jin Chem. 128, 234703 (2008)], we propose a rigorous and numerically convenient approach to simulate time-dependent quantum transport from first-principles. The proposed combines density functional theory with dissipation theory, results in useful tool for studying transient dynamics of electronic systems. Within the exact theoretical framework, construct number practical schemes simulating realistic systems...

10.1063/1.3475566 article EN The Journal of Chemical Physics 2010-09-16

A deep neural network is constructed to yield in principle exact exchange-correlation potential. It requires merely the electron densities of small molecules and ions yet can determine potentials large molecules. We train validate based on data for H2 HeH+ subsequently ground-state density stretched HeH+, linear H3+, H-He-He-H2+. Moreover, proven model van der Waals interaction by being trained validated a set containing He2. Comparisons B3LYP are given illustrate accuracy transferability network.

10.1021/acs.jpclett.9b02838 article EN The Journal of Physical Chemistry Letters 2019-11-06

Dual-atom catalysts (DACs) have recently emerged as promising and high-activity for the oxygen reduction reaction (ORR), a key process in many electrochemical energy conversion devices.

10.1039/d3ta05694e article EN Journal of Materials Chemistry A 2023-01-01

Despite their success, the results of first-principles quantum mechanical calculations contain inherent numerical errors caused by various intrinsic approximations. We propose here a neural-network-based algorithm to greatly reduce these errors. As demonstration, this combined calculation and neural-network correction approach is applied evaluation standard heat formation ΔfH⊖ for 180 small- medium-sized organic molecules at 298 K. A dramatic reduction clearly shown with systematic deviation...

10.1063/1.1630951 article EN The Journal of Chemical Physics 2003-11-22

We apply the Hubbard Hamiltonian to describe quantum-dot arrays weakly coupled two contacts. Exact diagonalization is used calculate eigenstates of containing up six dots and linear-response conductance then calculated as a function Fermi energy. In atomic limit peaks form distinct groups separated by intradot Coulomb repulsion, while in band occur pairs. The crossover studied. A finite interdot repulsion found cause interesting rearrangements spectrum.

10.1103/physrevb.50.8035 article EN Physical review. B, Condensed matter 1994-09-15

Organometallic halide perovskites have drawn substantial interest due to their outstanding performance in solar energy conversion and optoelectronic applications. The presence of ferroelectric domain walls these materials has shown a profound effect on electronic structure. Here, we use density-functional-based tight-binding model, coupled nonequilibrium Green's function method, investigate the effects transport properties charge carrier recombination methylammonium lead–iodide perovskite,...

10.1021/acs.jpcc.7b03091 article EN The Journal of Physical Chemistry C 2017-05-03

A practical first-principles scheme for time-dependent transport through realistic systems at finite temperature is established by the combination of density functional theory and nonequilibrium Green's-function formalism with wide-band limit approximation. This method extends adiabatic approximation developed earlier [Zheng et al., Phys. Rev. B 75, 195127 (2007)]. It implemented both tight-binding applied to simulate a carbon nanotube based electronic device demonstrate its validity.

10.1103/physrevb.87.085110 article EN Physical Review B 2013-02-08

Leveraging lexical constraint is extremely significant in domain-specific machine translation and interactive translation. Previous studies mainly focus on extending beam search algorithm or augmenting the training corpus by replacing source phrases with corresponding target These methods either suffer from heavy computation cost during inference depend quality of bilingual dictionary pre-specified user constructed statistical In response to these problems, we present a conceptually simple...

10.24963/ijcai.2020/496 article EN 2020-07-01

Electrochemical nitrate reduction to ammonia (NO3RR) is promising not only tackle environmental issues caused by but also produce at room temperatures. However, two critical challenges are the lack of effective electrocatalysts and understanding related reaction mechanisms. To overcome these challenges, we employed first-principles calculations thoroughly study performance mechanisms triple-atom catalysts (TACs) composed transition metals (including 27 homonuclear TACs 4 non-noble bimetallic...

10.1021/acsami.4c17726 article EN cc-by ACS Applied Materials & Interfaces 2025-01-10

Phosphorescent metal complexes, especially Pt(II) are widely used as emissive materials in organic light-emitting diodes (OLEDs) due to their tunable emissions and ease of preparation. To enable practical OLED...

10.1039/d4tc04046e article EN Journal of Materials Chemistry C 2025-01-01

Abstract Sodium‐based rechargeable batteries are some of the most promising candidates for electric energy storage with abundant sodium reserves, particularly, sodium‐based dual‐ion (SDIBs) perform advantages in high work voltage (≈5.0 V), high‐power density, and potentially low cost. However, irreversible electrolyte decomposition co‐intercalation solvent molecules at electrode interface under a charge state blocking their development. Herein, high‐salt concentration microenvironment is...

10.1002/adma.202416748 article EN Advanced Materials 2025-01-26

Abstract The utilization of phosphorescent metal complexes as emissive dopants for organic light-emitting diodes (OLEDs) has been the subject intense research. Cyclometalated Pt(II) are particularly popular triplet emitters due to their color-tunable emissions. To make them viable practical applications OLED emitters, it is essential develop with high radiative decay rate constants ( k r ) and photoluminescence quantum yields (PLQY). this end, an efficient accurate prediction tool highly...

10.1088/2752-5724/adb320 article EN cc-by Materials Futures 2025-02-06

Visible-range single-photon emitters (SPEs), based on hexagonal boron nitride (hBN), with exceptional optical performance have become an outstanding candidate for quantum technology. However, the control of carbon defect structures to obtain uniform and confined band structure remains elusive, restricting their integration into on-chip devices. Here, we demonstrate tuning hBN precisely emission in SPEs. The engineering from CB (carbon substituted at site) C2B–CN doped two sites one nitrogen...

10.1021/acsnano.4c11413 article EN cc-by ACS Nano 2025-02-28

To explore whether the density-functional theory non-equilibrium Green's function formalism (DFT-NEGF) provides a rigorous framework for quantum transport, we carried out time-dependent density functional (TDDFT) calculations of transient current through two realistic molecular devices, carbon chain and benzenediol molecule inbetween aluminum electrodes. The TDDFT simulations steady state exactly reproduce results fully self-consistent DFT-NEGF even beyond linear response. In contrast,...

10.1103/physrevb.83.245448 article EN Physical Review B 2011-06-29

Basing on our hierarchical equations of motion for time-dependent quantum transport [X. Zheng, G. H. Chen, Y. Mo, S. K. Koo, Tian, C. Yam, and J. Yan, Chem. Phys. 133, 114101 (2010)10.1063/1.3475566], we develop an efficient accurate numerical algorithm to solve the Liouville-von-Neumann equation. We real-time evolution reduced single-electron density matrix at tight-binding level. Calculations are carried out simulate transient current through a linear chain atoms, with each represented by...

10.1063/1.4737864 article EN The Journal of Chemical Physics 2012-07-27
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