A5101845491- Advanced Sensor and Energy Harvesting Materials
- ZnO doping and properties
- Transition Metal Oxide Nanomaterials
- Gas Sensing Nanomaterials and Sensors
- Conducting polymers and applications
- Ga2O3 and related materials
- GaN-based semiconductor devices and materials
- Innovative Energy Harvesting Technologies
- Advanced Memory and Neural Computing
- Advanced Thermoelectric Materials and Devices
- Ferroelectric and Piezoelectric Materials
- Dielectric materials and actuators
- Electronic and Structural Properties of Oxides
- Supercapacitor Materials and Fabrication
- Thermal properties of materials
- Gold and Silver Nanoparticles Synthesis and Applications
- Additive Manufacturing and 3D Printing Technologies
- Anodic Oxide Films and Nanostructures
- Semiconductor materials and devices
- Quantum and electron transport phenomena
- Graphene research and applications
- 2D Materials and Applications
- Electrocatalysts for Energy Conversion
- Thermal Radiation and Cooling Technologies
- Multiferroics and related materials
Sungkyunkwan University
2022-2025
Korea Institute of Science and Technology
2023-2024
Materials Science & Engineering
2022
Ulsan National Institute of Science and Technology
2011-2018
University of California, Santa Barbara
2008-2009
Pohang University of Science and Technology
2002-2006
Identifying reliable and sustainable sources of electricity is a significant challenge the present time. However, most energy-generation mechanisms produce unavoidable low-grade waste heat as byproduct while harvesting (or converting) electrical energy from conventional or renewable sources. Each year, over 60% primary wasted heat. Accordingly, considerable efforts are being made to convert this into usable using diverse conversion materials. In review, three actively investigated beyond...
Abstract In this study, the humidity‐resistant triboelectric nanogenerators (TENGs) utilizing MoS₂‐encapsulated SiO₂ nanoparticles (NPs), aimed at enhancing self‐powered gas sensing applications, are reported. The core‐shell structure, featuring a thin MoS₂ layer uniformly grown on SiO₂, addresses common humidity‐induced performance degradation. growth mechanism involves decomposition and sulfidation of molybdenum species, with selectively nucleating to form stable, hydrophobic shell. This...
Optimization of the formulation and processability 3D-printable ceramic polymer composites offers a solution to piezoelectric materials with high printability responses. Our approach is based on both composite auxetic structural design. The optimal exhibited strong interfacial adhesion, dispersion stability, low viscosity, smooth surface, resulting in piezoelectricity. In addition, processing parameters, such as intensity application time UV laser, were optimized for processability....
Single silver nanowires produced by DC electrodeposition in porous anodic alumina templates were surface-functionalized with the bifunctional molecule 4-aminobenzenthiol (ABT) then exposed to aqueous nanoparticles resulting a nanoparticle-decorated nanowire. The polarization dependent surface-enhanced Raman (SERS) signal from this system showed significant intensity anisotropy when measured at midsection of nanowire, where largest SERS intensities observed incident light was polarized...
Exceptionally sensitive hydrogen sensors were produced using Pd-nanoparticle-decorated, single vanadium dioxide nanowires. The high-sensitivity arises from the large downward shift in insulator to metal transition temperature following adsorption on and incorporation of atomic hydrogen, by dissociative chemisorption Pd, VO2, producing ∼1000-fold current increases. During a rapid initial process, is decreased >10 °C even when exposed trace amounts gas. Subsequently, continues diffuse into VO2...
Abstract Despite the rapid development of various wearable generators to harvest energy from human activity, they are limited single or intermittent power generation. Here, stretchable and washable harvesting fabric is reported, which enables biomechanical biochemical generation through co‐weaving triboelectric generator (TEG) perspiration electric (PEG)‐based fibers. The two approaches can work individually simultaneously, thereby combating humidity increasing electrical output. maximum...
Abstract Eco‐friendly triboelectric nanogenerator (eco‐TENG) is considered as a next‐generation renewable kinetic energy‐harvesting technology, especially for its potential use power supply unit self‐powered electronics. For eco‐TENGs, nature‐derived biomaterials, which are non‐toxic to human and environment, highly biocompatible, abundant in nature, used tribopositive or tribonegative materials, both. Here, recent progress biomaterials exploited eco‐TENGs their performances reviewed,...
Uniform nanogaps were produced in silver nanowires previously fabricated by AC electrodeposition porous anodic alumina templates and released dissolving the oxide matrix. Configuring with electrodes passing current through them created electromigration. approximately perpendicular to axes of widths range ∼17 ∼40 nm. Gaps as small 5 nm but less uniform geometries could also be this manner. A heuristic model, which electromigrative diffusional effects are included, is used relate size nanogap...
Abstract The paper extensively explores moisture‐induced charge decay in tribo‐materials, addressing generation fundamentals and overcoming strategies. Triboelectric effect contact electrification models are discussed, with corona charging hydro‐charging as effective methods. Moisture‐induced adverse effects, such swelling dissipation, outlined. Electronegativity dangling bonds' roles traps explored, along the impact of functionalities on materials. Various strategies, including hydrophobic...
Non-layered 2D materials offer unique and more advantageous physicochemical properties than those of conventional layered materials. However, the isotropic chemical bonding nature non-layered hinders their lateral growth, making synthesis large-area continuous thin films challenging. Herein, a facile kinetically tailored vapor deposition (KT-CVD) approach is introduced for molybdenum nitride (MoN), representative material. Large-scale MoN with dimensions up to 1.5 cm × are obtained by...
Vertically well-aligned (Zn,Mn)O nanorods (see Figure) that show ferromagnetic behavior at room temperature have been grown on sapphire substrates by chemical vapor deposition. The high optical quality of the has demonstrated photoluminescence spectroscopy. These nanowires may find use in future nanoscale magneto-optic and magneto-electronic applications.
Abstract Reducing the impedance of a triboelectric nanogenerator (TENG) without power loss is crucial for enhancing its energy conversion efficiency and overall performance. In this paper, novel signal management structure, based on newly designed sliding‐mode TENG, aimed at effectively reducing by converting narrow, instantaneous signals into broader ones presented. This transformation accomplished adding grounded electrode connected to high‐inductive inductor fine‐tuning parasitic...
Current core-shell hybrids used in diverse energy-related applications possess limited dispersibility and film uniformity that govern their overall performances. Herein, we showcase superdispersible (P2VP@BaTiO3) composed of a poly(2-vinylpyridine) (P2VP) (5-20 wt %) barium titanate oxide (BaTiO3), maximizing dielectric constants by forming the high-quality uniform films. The P2VP@BaTiO3-based triboelectric nanogenerators (TENGs), especially 10 % P2VP (P2VP10@BaTiO3)-based one, deliver...
A dilute magnetic semiconductor was achieved by implanting Mn ions into p-type GaN and subsequent annealing. The ferromagnetic property obtained after annealing at 800 °C. This attributed to the formation of Ga–Mn phases. Higher temperature 900 °C reduced signal produced antiferromagnetic Mn–N compounds such as Mn6N2.58 Mn3N2, leaving N vacancies. provides evidence that vacancies play a critical role in weakening Mn-implanted GaN.
Single-crystal VO2 nanowires were synthesized using atmospheric-pressure and physical vapor deposition outfitted with electrodes for current−voltage measurements. The Mott insulator-to-metal transition temperatures of several varying lateral dimensions determined by measuring the voltage values at which sharp current step, signaling that occurrence or reverse transitions, had taken place. observed temperatures, ranged between 62 70 °C measured, trended downward decreasing nanowire width. We...
We report highly effective hydrogen gas detection based on the metal–insulator transition (MIT) by electrothermally induced Pd-nanoparticles-decorated vanadium oxide (VO2) nanowire prepared efficient and size-controllable growth method originating from V2O5 thin film driven supercooled liquid nanodroplets. By irradiating a well-defined electron beam into nanowires, we could significantly increase conductivity up to four times with only modest change in semiconductor-to-metal temperature (<2...
We studied insulator–metal transitions in VO2 nanobeams for both abrupt and gradual changes applied electric fields. Based on the observations, Poole–Frenkel effect explained transition, while case is found to be dominated by Joule heating phenomenon. also carried out power model finite element method based simulations which supported phenomena transition. An in-principle demonstration of effect, performed using a square voltage pulse 1 µs duration, further confirms proposed transition...
Fe nanowires were fabricated by electrodeposition into nanoporous alumina templates grown in sulfuric and oxalic acid a pulse electrodeposition. A 42 nm diameter nanowire anodized pores is essentially single-crystalline object that grows preferentially so as to align its (110) axis along the long of pore. Its coercivity 1654 Oe squareness 0.66 for axially aligned magnetic fields. For an pores, both (200) diffraction peaks are observed, suggesting polycrystalline object. reduced 1120 0.47,...
Neuromorphic computing systems that mimic the human brain have recently attracted substantial attention because they allow for efficient processing of large amounts data. These are composed neurons and synapses to transfer information; play a particularly important role in transmitting integrating processed signals between neurons. The ferroelectric field-effect transistors (FeFETs) can meet required properties artificial synaptic devices channel current be controlled with changes applied...