A5002866197- Silicon Nanostructures and Photoluminescence
- Perovskite Materials and Applications
- Thin-Film Transistor Technologies
- ZnO doping and properties
- Solid-state spectroscopy and crystallography
- Advanced Thermoelectric Materials and Devices
- Nanowire Synthesis and Applications
- Copper-based nanomaterials and applications
- Chalcogenide Semiconductor Thin Films
- Thermal Radiation and Cooling Technologies
- Force Microscopy Techniques and Applications
- Advanced Thermodynamics and Statistical Mechanics
- RFID technology advancements
- Topic Modeling
- Energy Harvesting in Wireless Networks
- Electronic and Structural Properties of Oxides
- Semiconductor materials and devices
- Optical properties and cooling technologies in crystalline materials
- Quantum Dots Synthesis And Properties
- Silicon and Solar Cell Technologies
- Antenna Design and Analysis
- Advanced Photocatalysis Techniques
- Photonic and Optical Devices
- Natural Language Processing Techniques
- Mechanical and Optical Resonators
VNU University of Science
2015-2024
Vietnam National University, Hanoi
2017-2024
Hanoi University of Science and Technology
2017-2020
Vietnam Academy of Science and Technology
2018
Centre National de la Recherche Scientifique
2005-2013
Laboratoire de Physique des Interfaces et des Couches Minces
2005-2013
École Polytechnique
2005-2013
Vietnam National University Ho Chi Minh City
2010-2013
Spectra Research (United States)
2007
The synthesis of silicon nanocrystals in standard radio-frequency glow discharge systems is studied with respect to two main objectives: (i) the production devices based on quantum size effects associated small dimensions and (ii) polymorphous polycrystalline films which are elementary building blocks. In particular we discuss results mechanisms nanocrystal formation their transport towards substrate. We found that can contribute a significant fraction deposition (50–70%) they be positively...
The photocatalytic activity of p-Si/p-CuO buffer layer/n-ZnO nanorod (NR) composite films was studied using experimental and simulation methods. results indicated that in the p-Si/p-CuO/n-ZnO film, 250 nm CuO layer contributes highest value 11% to total current density compared p-Si/n-ZnO film. Besides that, also by introducing p-CuO layer, pseudo-order rate constant (k) could be enhanced up 12% film without - Furthermore, recycle result k decreased sharply after first three reaction cycle...
Detecting cybersecurity events is necessary to keep us informed about the fast growing number of such reported in text. In this work, we focus on task event detection (ED) identify trigger words for domain. particular, facilitate future research, introduce a new dataset problem, characterizing manual annotation 30 important types and large size develop deep learning models. Comparing prior datasets task, our involves more supports modeling document-level information improve performance. We...
The driving factors behind the development of large language models (LLMs) with impressive learning capabilities are their colossal model sizes and extensive training datasets. Along progress in natural processing, LLMs have been frequently made accessible to public foster deeper investigation applications. However, when it comes datasets for these LLMs, especially recent state-of-the-art models, they often not fully disclosed. Creating data high-performing involves cleaning deduplication...
It is generally accepted that increasing the deposition rate of amorphous (a-Si : H) and microcrystalline (μc-Si thin films grown by plasma enhanced chemical vapour leads to a deterioration in films' properties. This 'common sense' rule places an upper limit on for given film quality thus photovoltaic device efficiency. While this applies a-Si H μc-Si produced dissociation silane via 'radical path', we have found it possible increase still improve or maintain properties when process involves...
Surface modification of interdigitated DNA sensors by polypyrrole nanowires and gold nanoparticles has been analyzed systematically. Polypyrrole with diameter 200 nm length 5 μm were electrochemically synthesized on the surface electrodes subsequently decorated 20 nanoparticles. Electrochemical impedance spectroscopy differential voltage measurements conducted to detect concentrations. We have observed a logarithmic dependence analytical signals concentration. A formula for estimating limit...
Organometal halide perovskites have been studied extensively during the last ten years for their interesting applications in solar cells and optoelectronics. One drawback of these materials is presence lead inside compound, thus limiting practical applications. Replacing with tin has one implemented approaches lead-free perovskites. In this paper, we report on synthesis organo mixed CH3NH3SnBrxCl3-x at room temperature an aqueous acidic mixture between HCl H3PO2 without need protecting...
Light–matter interaction between quantum emitters and optical cavities plays a vital role in fundamental photonics the development of optoelectronics. Resonant metasurfaces are proven to be an efficient platform for tailoring spontaneous emission (SE) emitters. In this work, we study interplay quasi-2D perovskites dielectric TiO 2 metasurfaces. The metasurface, functioning as open cavity, enhances electric fields near its plane, thereby influencing emissions perovskite. This is verified...
Viet Lai, Chien Nguyen, Nghia Ngo, Thuat Franck Dernoncourt, Ryan Rossi, Thien Nguyen. Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing: System Demonstrations. 2023.
The growth of silicon nanocrystals in high pressure and dilution silane plasmas is investigated by using the temporal evolution self-bias on radio frequency electrode transmission electron microscopy. A square-wave-modulated plasma was used order to control monodispersed nanoparticles with sizes smaller than 12nm. To this end, time kept below 1s. radial rate varied range from 7.5to75nm∕s changing partial pressure. Nanoparticles grown silane-helium discharges have been found amorphous while...
>700 W continuous-wave output power has been demonstrated from a single 1 cm-wide laser bar (∼940 nm) with 77% fill factor. Maximum conversion efficiency (PCE) of 65% achieved. Facet density 170 mW/µm and maximum PCE 69% have measured for 10% fill-factor bars 3 mm cavity length.
At the ultra-thin film limit, quantum confinement strongly improves thermoelectric figure of merit in materials such as Sb2Te3 and Bi2Te3. These high quality films have only been realized using well controlled techniques molecular beam epitaxy. We report a twofold increase Seebeck coefficient for both p-type n-type Bi2Te3 thermal co-evaporation, an affordable approach. thick limit greater than 100 nm, their coefficients are around μV/K, similar to results obtained other works. When thinner...
The nanometer-scale (medium range) structural order in hydrogenated polymorphous silicon films is analyzed using fluctuation electron microscopy. growth regime occurs under relatively high gas pressure during plasma-enhanced chemical vapor deposition, such that small aggregates and nanocrystals form the phase impinge on film surface. All samples appear completely amorphous diffraction or Raman scattering analyses. In microscopy, carried out transmission microscope, statistical variance V...
We report on electroluminescent P-I-N diodes containing silicon nanocrystals embedded in an amorphous carbon matrix as emitting material. The as-deposited devices mostly contain Si nanoparticles and emit weakly the IR. After a forming process consisting of application high current density to structure, intensity electroluminescence increases by factor 30 shifts red. is characterized measurements induced crystallization evidenced Raman scattering spectroscopy measurements. These results are...
We demonstrate the possibility to map nanoscale charge transfers between quantum electronic levels at room temperature, using noncontact atomic force microscopy and Kelvin in a regime of weak electromechanical coupling. A two-level system is studied, consisting degenerately doped silicon nanocrystals on substrates, with size 2--50 nm range, which energy spacing tuned by nanocrystal confinement over $\ensuremath{\approx}1\text{ }\text{eV}$ range. The ionization found follow an compensation...
An antenna structure for UHF RFID tag matched to ST Microelectronics XRAG2 passive IC is proposed in this paper. The design realized on PET (Polyethylene Terephthalate) substrate that has the overall dimension of 82.5 mm × 45.29 mm. simulation shows zigzag-shaped return loss at resonant frequency −39 dB and omni-directional radiation characteristics with maximum gain about 1.97 dBi much better than initial meander dipole. prototype was tested by Rohde & Shwarz ZVB Vector Network Analyzer...
Semiconductor junctions are the basis of electronic and photovoltaic devices. Here, we investigate formed from highly doped (ND≈1020−1021cm−3) silicon nanocrystals (NCs) in 2–50 nm size range, using Kelvin probe force microscopy experiments with single charge sensitivity. We show that transfer NCs towards a two-dimensional layer experimentally follows simple phenomenological law, corresponding to formation an interface dipole linearly increasing NC diameter. This feature leads analytically...