A5020260724- Luminescence Properties of Advanced Materials
- Theoretical and Computational Physics
- Perovskite Materials and Applications
- Complex Systems and Time Series Analysis
- Gas Sensing Nanomaterials and Sensors
- bioluminescence and chemiluminescence research
- ZnO doping and properties
- Quantum Dots Synthesis And Properties
- Glass properties and applications
- Advanced Photocatalysis Techniques
- Material Dynamics and Properties
- Ga2O3 and related materials
- Quantum many-body systems
- Ammonia Synthesis and Nitrogen Reduction
- Semiconductor Quantum Structures and Devices
- Liquid Crystal Research Advancements
- Microwave Dielectric Ceramics Synthesis
- X-ray Diffraction in Crystallography
- Thermal Expansion and Ionic Conductivity
- Material Science and Thermodynamics
- Elasticity and Material Modeling
- Complex Network Analysis Techniques
- Advanced Physical and Chemical Molecular Interactions
- Strong Light-Matter Interactions
- Chalcogenide Semiconductor Thin Films
Hanoi University of Science and Technology
2014-2025
Osaka University
2009-2010
Osaka Health Science University
2010
Although it has been extensively studied for decades, the α-Al 2 O 3 :Cr 3+ phosphor rarely investigated horticultural lighting.
This work reports an excellent quantum efficiency and superior color purity CaAl12O19–CaAl4O7–MgAl2O4:Mn4+ (CCM:Mn4+) red-emitting phosphor. phosphor can be excited by a broad excitation band ranging from 300 to 500 nm, it generates intense broadband red emission peaking at 656 nm. The CCM:0.5%Mn4+ phosphor-possessed of 100%, long lifetime 0.49 ms, high activation energy 0.286 eV. Four different prototypes plant growth light-emitting diodes (LEDs) with efficiencies 81.8, 72.1, 67.2, 61.1%...
Optical characteristics of Gd 3 Ga 5 O 12 :Mn and prototype UV-driven LED coated with phosphor.
Ordering of the three-dimensional Heisenberg spin glass with Gaussian coupling is studied by extensive Monte Carlo simulations. The model undergoes successive chiral-glass and spin-glass transitions at nonzero temperatures T_{CG} > T_{SG} 0, exhibiting spin-chirality decoupling.
The nature of the ordering three-dimensional isotropic Heisenberg spin glass with nearest-neighbor random Gaussian coupling is studied by extensive Monte Carlo simulations. Several independent physical quantities are measured both for and chirality, including correlation-length ratio, Binder order parameter, overlap distribution function, nonself-averageness parameter. By controlling effect correction-to-scaling, we have obtained a numerical evidence occurrence successive chiral-glass...
The measurements of the magnetic and nematic correlation lengths in a generalization two-dimensional XY model on square lattice are presented using classical Monte Carlo simulation. full phase diagram is reexamined based these lengths, demonstrating their power studying generalized models. ratio between length size has distinctive behaviors which can be used to distinguish different types transition. More importantly, give more insights into tricritical region where paramagnetic, nematic,...
The development of full-visible-spectrum phosphors is essential for next-generation light-emitting devices with better light quality.
Eu3+-doped phosphors have been much attractive owing to their narrow-band red emission peak at 610-630 nm with high color purity; however, the weak and narrow absorption band in NUV region limits applications. Doping a higher amount of Eu3+ ions into non-concentration quenching host could be key enhancing efficiency value intensity. Hence, design Eu3+-heavily doped suitable lattice is for In this study, red-emitting Gd(BO2)3-Y3BO6-GdBO3 (GdYGd:Eu3+) phosphor quantum 58.4% excellent purity...
We study phase transition properties of the two-dimensional q-state clock model by an extensive Monte Carlo simulation. By analyzing Binder ratio and its temperature derivative, we confirm that exhibits two distinct Kosterlitz-Thouless transitions for q=5,6 but it has one second-order q=4. The critical temperatures are estimated quite accurately from crossing behavior (for q<5) negative divergent dips derivative q≥5) around these points. also calculate correlation length, helicity modulus,...
We study the issue of spin-chirality decoupling or coupling in ordering Heisenberg spin glass by performing large-scale Monte Carlo simulations on a one-dimensional spin-glass model with long-range power-law interaction up to large system sizes. find that occurs for an intermediate range exponent. Implications corresponding d-dimensional short-range are discussed.
Blue/red emitting bi-phase Eu3+/Eu2+-doped SrPCl-based phosphors were synthesized using a co-precipitation method followed by sintering process in air ambient and reducing gas. The effect of sintering/reducing temperature Eu concentration on the structure, morphology luminescent spectra investigated. XRD patterns analysis showed that contain Sr5(PO4)3Cl Sr3(PO4)2 due to decomposition Cl atoms at high temperature. decomposition, however, could be prevented doping content. optimum PL...
Abstract Orange‐red‐emitting Eu 3+ ‐doped Ca 9 Gd(PO 4 ) 7 phosphors have been obtained by a sol‐gel technique. These phosphors, excited UV (270 nm) and near light (394 nm), emit orange‐red in the range of 580–710 nm. The :7 mol% phosphor annealed at 1100 °C shows highest PL intensity. Judd‐Ofelt analysis reveals that neighbor surroundings ions are asymmetric, lowest asymmetry value is found dopant ratio mol%. optimal wavelength 394 nm displays an excellent thermal stability (∼76.4 % 160 °C)...
The room-temperature ferromagnetism of diluted magnetic semiconductors (DMS) doped with light elements has been extensively studied for potential applications in spintronic devices. existence and stability DMS low concentration regime is an interesting topic, followed by researches using both Monte Carlo (MC) simulation first-principle calculations. Both continuous discrete spin models were developed to describe the ferromagnetic phase but it still unclear, which one produces a better...