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Nguyen Thanh Tien

Publications and source records attributed to Nguyen Thanh Tien.

5 recordsLinked to original sources
arXiv2026

A comparative first-principles investigation of bilayer NbOX2 (X=Cl, Br, I) for Photocatalytic water splitting applications

Motivated by our previous work on bulk NbOX2 , where we have reported its high 1dielectric polarisation and finite piezoelectric response, this work extends to its 2D homo bilayer system to explore its potential for photocatalytic water splitting. Herein, density functional theory (DFT) were employed in probing the structural, electronic, optical, and photocatalytic properties of 2D homo bilayer NbOX2 (X = Cl, Br, and I). Our results show that structurally, NbOCl2 and NbOBr2 prefer AC bilayer stacking,while AB stacking was preferred by NbOI2 . All the considered bilayers are dynamically, thermally, and mechanically stable. From the analysis of electronic structure we have found a decreasing trend in the energy band gap as X goes down the group from Cl to I, with the position of the valence band maximum shifting upward along the high symmetry points. In terms of carrier mobility, all 2D bilayer systems possess high carrier mobility comparable to known 2D materials. It also exhibits an anisotropic carrier transfer property by which charge carriers are separated efficiently. These materials show similar trends to BiOI and PtSe2 , in which photocatalytic efficiency was increased by forming the multiple layers. The materials under investigation are suitable for photocatalytic water splitting under visible and ultraviolet regions with absorption coefficients of 105 cm-1.

cond-mat.mtrl-sci↗
arXiv2026

Efficient molecular dynamics simulation of 2D penta-silicene materials using machine learning potentials

Machine Learning Interatomic Potentials (MLIPs) are a modern computational method that allows achieving near-quantum mechanical accuracy (DFT) while still describing large-scale systems in molecular dynamics (MD) simulations. In this work, we use MLIP from DeepMD package and the classical Tersoff potential for SiC (Tersoff.SiC potential) to fully and accurately describe atomic interactions and apply them to molecular dynamics simulations of penta silicene sheet. The results show that the melting points (T$_g$) temperatures of the system in the canonical NVT and isobaric NPT sets are 632 K and 606 K, while the Tersoff.SiC potential have the high melting points, respectively. In addition, the radial distribution function exhibits characteristic peaks at interatomic distances of 2.275 Å\text{} and 2.375 Å, while the Tersoff.SiC potential only describe distance of 2.375 Å. Furthermore, penta silicene was also simulated using on-the-fly machine learning for 10 ps to evaluate the structural stability of the system. This study investigates the thermodynamic properties of two-dimensional penta silicene sheets with pentagonal structures using a high-precision, cost-effective method, contributing further evidence to support experimental synthesis and opening up potential future applications of this material.

cond-mat.mtrl-sci↗
arXiv2024

Symmetry-Driven Valleytronics in Single-Layer Tin Chalcogenides

The concept of valleytronics has recently gained considerable research attention due to its intriguing physical phenomena and practical applications in optoelectronics and quantum information. In this study, by employing GW-BSE calculations and symmetry analysis, we demonstrate that single-layer orthorhombic SnS and SnSe possess high carrier mobility and exceptional excitonic effects. Especially, these materials display spontaneous linearly polarized optical selectivity, a behavior that differs from the valley-selective circular dichroism observed in the hexagonal lattices. Specifically, when subjected to a zigzag polarization of light, only the A exciton (stemming from the X valley) becomes optically active, while the B exciton (arising from the Y valley) remains dark. The armchair-polarized light triggers the opposite behavior. This selective optical excitation arises from the symmetry of the bands under mirror symmetry. Additionally, the study reveals a strong coupling between valley physics and ferroelectricity in layered tin chalcogenides, enabling the manipulation of electronic transport and exciton polarization. Layered tin chalcogenides thus emerge as promising candidates for both valleytronic and ferroelectric materials.

cond-mat.mtrl-sci↗
arXiv2023

Unlocking the Potential of GeS Monolayer: Strain-Enabled Control of Electronic Transports and Exciton Radiative Lifetimes

Monolayer germanium sulfide is gaining significant attention for its exceptional anisotropic electronic conductance, notable excitonic effects, and wide range of potential applications. In our study, we used density functional theory, many-body perturbation theory, and non-equilibrium Green function to investigate electronic transport properties and exciton radiative lifetime of single-layer germanium sulfide. Our theoretical findings showed that applying up to 8 percent compressive strain increased carrier mobility by nearly threefold, and thus, dramatically enhance the device's current intensity. Moreover, we observed that strain engineering allowed fine-tuning of the electron-hole recombination time. At 6 percent tensile strain, the effective radiative lifetime was as short as 19 picoseconds, which is 4.5 times faster than the intrinsic state and 80 times faster than at 8 percent compressive strain. These results highlight the potential of strain engineering to customize the electronic and optical properties of GeS monolayer for specific electronic, optoelectronic, and photovoltaic device requirements

cond-mat.mtrl-sci↗