A5101522905- Laser-Matter Interactions and Applications
- Quantum Dots Synthesis And Properties
- Advanced Fiber Laser Technologies
- Atomic and Molecular Physics
- Advanced X-ray Imaging Techniques
- Perovskite Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Particle Accelerators and Free-Electron Lasers
- Chalcogenide Semiconductor Thin Films
- High voltage insulation and dielectric phenomena
- ZnO doping and properties
- Laser Design and Applications
- Thermal Analysis in Power Transmission
- Ga2O3 and related materials
- Laser-induced spectroscopy and plasma
- X-ray Spectroscopy and Fluorescence Analysis
- Organic Electronics and Photovoltaics
- Terahertz technology and applications
- Power Transformer Diagnostics and Insulation
- Mass Spectrometry Techniques and Applications
- Gas Sensing Nanomaterials and Sensors
- Gold and Silver Nanoparticles Synthesis and Applications
- Spectroscopy and Quantum Chemical Studies
- Recommender Systems and Techniques
- Crystallography and Radiation Phenomena
Gyeongsang National University
2025
Korea University
2020-2024
Korea Maritime and Ocean University
2021-2023
Kyung Hee University
2022-2023
Pohang University of Science and Technology
2010-2022
Korea Foundation for Max Planck POSTECH
2013-2022
Pohang Accelerator Laboratory
2010-2022
Shanghai Shipbuilding Technology Research Institute
2014
Korea Institute of Science and Technology
2005-2006
University of California, San Diego
2003
Abstract Solution‐processed ternary‐compound semiconductor AgBiS 2 colloidal quantum dots (CQDs) are promising light‐absorbing materials owing to their nontoxicity and high absorption coefficient (>10 6 cm −1 ). However, rational strategies passivate multi‐facet of CQDs manufacture stable CQD inks have not yet been proposed. In this paper, a ligand passivation strategy is proposed using solution‐phase exchange method. A quadruple‐ligand ensemble employed demonstrate multifaceted on highly...
Abstract Solution‐processed low‐bandgap semiconductors are crucial to next‐generation infrared (IR) detection for various applications, such as autonomous driving, virtual reality, recognitions, and quantum communications. In particular, III–V group colloidal dots (CQDs) interesting nontoxic bandgap‐tunable materials suitable IR absorbers; however, the device performance is still lower than that of Pb‐based devices. Herein, a universal surface‐passivation method InAs CQDs enabled by...
Abstract Infrared (IR) optoelectronics have become important owing to their various applications, such as recognition, autonomous driving, and quantum communications. In particular, detection beyond 1400‐nm wavelength in the shortwave IR (SWIR) spectrum (i.e., 1550 nm) is for eye safety, long‐range communication. Recently, group III–V (InAs or InSb) colloidal dots (CQDs) attracted considerable interest due broadband optical tunability toxic‐elements (Pb Hg)‐free properties. Herein, a new...
The construction of Pohang Accelerator Laboratory X-ray Free-Electron Laser (PAL-XFEL), a 0.1-nm hard free-electron laser (FEL) facility based on 10-GeV S-band linear accelerator (LINAC), is achieved in Pohang, Korea by the end 2016. 1.11 km-long building was completed 2014, and installation LINAC undulators started January 2015. LINAC, together with beamlines, commissioning began April 2016, first lasing FEL line 14 June progress PAL-XFEL its commission are reported here.
Abstract Emerging semiconducting materials show considerable promise for application in the development of next‐generation optoelectronic devices. In particular, broadband light detection is crucial various applications, including multispectral imaging and cognition. Therefore, tuning physical properties semiconductors thereby building an efficient heterojunction are important achieving a high‐performance photodetection device. this study, heavy p‐type colloidal quantum dot (CQD) synthesized...
Abstract Extended shortwave infrared (eSWIR) photodetectors that employ solution‐processable semiconductors have attracted attention for use in applications such as ranging, night vision, and gas detection. Colloidal quantum dots (CQDs) are promising materials with facile bandgap tunability across the visible‐to‐mid‐infrared wavelengths. However, toxic elements, Hg Pb, slow response time of CQD‐based IR photodetectors, limit their commercial viability. This article presents a novel eSWIR...
Broadband optoelectronics, which extend from the UV to IR regions, are crucial for imaging, autonomous driving, and object recognition. In particular, photon detection efficiency relies significantly on semiconductor properties, such as absorption coefficients electron–hole pair generation rate, can be optimized by designing a suitable p–n junction. this study, we devise giant PbS colloidal quantum dots (G-PbS CQDs) that exhibit high broadband absorption. To leverage these exceptional...
High-contrast, intense single-cycle pulses are highly desirable tools in ultrafast science, enabling highest temporal resolution, pushing matter to extreme conditions, and serving as drivers petahertz electronics. In this Letter, we use thin solid plates a double multi-plate supercontinuum configuration, delivering broadband spectrum spanning from <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mo>∼</mml:mo> <mml:mspace width="negativethinmathspace"/>...
Purpose Textual information about restaurants, such as online reviews and food categories, is essential for consumer purchase decisions. However, previous restaurant recommendation studies have failed to use textual containing predicting preferences effectively. This study aims propose a novel model effectively estimate the assessment behaviors of consumers multiple attributes. Design/methodology/approach The authors collected 1,206,587 from 25,369 46,613 restaurants Yelp.com. Using these...
Abstract Frequency combs, millions of narrow-linewidth optical modes referenced to an atomic clock, have shown remarkable potential in time/frequency metrology, atomic/molecular spectroscopy and precision LIDARs. Applications extended coherent nonlinear Raman molecules quantum metrology for entangled qubits. combs will create novel possibilities nano-photonics plasmonics; however, its interrelation with surface plasmons is unexplored despite the important role that plasmonics plays optics...
High-order harmonic generation (HHG) is a fundamental process which can be simplified as the production of high energetic photons from material subjected to strong driving laser field. This highly nonlinear optical contains rich information concerning electron structure and dynamics matter, for instance, gases, solids liquids. Moreover, HHG has recently attracted attention both attosecond science condensed matter physicists, since spectra carry electron-hole in bands inter- intra-band...
The fabrication of heterostructures via solution process is one the essential technologies for realizing efficient advanced-generation optoelectronics. Hybrid structures comprising colloidal quantum dots (CQD) and organic semiconducting molecules are garnering considerable research interest because their complementing optical electrical properties. However, blending both materials forming a stable electronic ink challenge owing to solubility mismatch. Herein, CQD:organic ternary-blended...
A 10-Hz repetition rate, 60-TW peak power, Ti:sapphire laser system was developed for use in experiments where relativistic effects dominate the physics. The temporal, spectral, energy and spatial characteristics of pulses were measured single shot format. pulse duration ranged from 22 fs to 25 averaged 1.3 J. Atomic photoionization measurements quantified intensity situ. indicated an at least 510 19 W/cm 2 produced.
Starting from a mixture of Zn and BiI3, we grew nanowires nanoplates on an oxidized Si substrate at relatively low temperatures 250 300 degrees C, respectively. The ZnO had diameters approximately 40 nm along the [110] direction rather than conventional [0001] direction. thicknesses lateral dimensions 3-4 microm. growth both is dominated by synergy vapor-liquid-solid (VLS) conducting. Analysis photoluminescence spectra suggested that contain more oxygen vacancies have higher...
With the continuous growth in Home Meal Replacement (HMR) market, significance of recommender systems has been raised for effectively recommending customized HMR products to each customer. The extant literature mainly focused on enhancing performance based offline evaluations customers’ past purchase records. However, since existing evaluation methods evaluate consistency recommendation list with ones purchased by customers from test dataset, they are incapable encompassing components such...
Colloidal quantum dots (CQDs) are promising semiconductors for optoelectronic applications owing to their bandgap tunability and solution processability. Historically, ethanedithiol has been widely employed as a surface ligand form p‐type CQD layer via layer‐by‐layer process. However, the limited control of characteristics reduces device performance, high reactivity processing solvents degrade underlying layer. In this study, thiol‐free is demonstrated by creating native CQDs during...
Zinc oxide nanowires were obtained through a vapor transport route at temperatures as low around 250°C. The diameters of the are ∼40nm and their lengths reach up to few microns. high-resolution transmission electron microscopy showed that ZnO hexagonal wurtzite structures with [112¯0] growth direction. Raman spectrum reveals high-quality crystal have an oxygen deficiency. energy dispersive x-ray spectroscopy result verifies contain small amount Bi besides Zn O. investigation mechanism...
Zinc oxide bicrystal nanobelts were fabricated via a vapor phase transport of powder mixture Zn, BiI3, and MnCl2∙H2O at temperatures as low 300°C. The nanobelts, growing along the [011−3] direction, have widths 40–150nm lengths tens microns. energy dispersive x-ray spectroscopy result verifies that contain higher concentration both Bi Mn grain boundary. investigation growth mechanism proposes MnBi may induce formation nanobelts. Photoluminescence spectra show ultraviolet emission has...