A5020025335- Graphene research and applications
- 2D Materials and Applications
- Advanced Sensor and Energy Harvesting Materials
- Plasmonic and Surface Plasmon Research
- MXene and MAX Phase Materials
- Perovskite Materials and Applications
- Advanced Memory and Neural Computing
- Gold and Silver Nanoparticles Synthesis and Applications
- Spatial and Panel Data Analysis
- Conducting polymers and applications
- Carbon Nanotubes in Composites
- Invertebrate Immune Response Mechanisms
- Quantum and electron transport phenomena
- Organic Light-Emitting Diodes Research
- Neuroscience and Neural Engineering
- Gas Sensing Nanomaterials and Sensors
- Quantum Dots Synthesis And Properties
- Advanced Materials and Mechanics
- Neuroscience and Neuropharmacology Research
- Neural dynamics and brain function
- Urban Transport and Accessibility
- Organic Electronics and Photovoltaics
- Advancements in Battery Materials
- Advanced Photocatalysis Techniques
- Soft Robotics and Applications
Yonsei University
2013-2025
Korea Advanced Institute of Science and Technology
2024
Seoul National University
2009-2024
Korea Electronics Technology Institute
2024
Massachusetts Institute of Technology
2020-2023
McGovern Institute for Brain Research
2020
Konkuk University
2019-2020
Sungkyunkwan University
2010-2019
Hanyang University
2013-2016
Anyang University
2016
We developed means to produce wafer scale, high-quality graphene films as large 3 inch size on Ni and Cu under ambient-pressure transfer them onto arbitrary substrates through instantaneous etching of metal layers. also demonstrated the applications large-area for batch fabrication field-effect transistor (FET) arrays stretchable strain gauges showing extraordinary performances. Transistors showed hole electron mobilities device 1,100 cm2/Vs 550 at drain bias -0.75V, respectively. The...
A high-performance novel photodetector is demonstrated, which consists of graphene and CH3 NH3 PbI3 perovskite layers. The resulting hybrid exhibits a dramatically enhanced photo responsivity (180 A/W) effective quantum efficiency (5× 10(4) %) over broad bandwidth within the UV visible ranges.
We fabricated dye-sensitized MoS2 photodetectors that utilized a single-layer treated with rhodamine 6G (R6G) organic dye molecules (with an optical band gap of 2.38 eV or 521 nm). The proposed photodetector showed enhanced performance broad spectral photoresponse and high photoresponsivity compared the properties pristine photodetectors. R6G deposited onto layer increased photocurrent by order magnitude due to charge transfer photoexcited electrons from layer. Importantly, photodetection...
MXene has not yet been investigated in optical applications because it is a newly suggested two-dimensional material. In the present work, first investigation of prospects as novel nanodevice was done by applying strain to monolayer Sc2CO2 using first-principles density-functional theory. This single-layer material experiences an indirect direct band gap transition with variation size at relatively small critical about 2%. The work emphasizes that can become promising for modulating...
Broad adoption of magnetic soft robotics is hampered by the sophisticated field paradigms for their manipulation and complexities in controlling multiple devices. Furthermore, high-throughput fabrication such devices across spatial scales remains challenging. Here, advances fiber-based actuators elastomer composites are leveraged to create 3D robots controlled unidirectional fields. Thermally drawn elastomeric fibers instrumented with a composite synthesized withstand strains exceeding 600%....
We describe a method for synthesizing large-area and uniform molybdenum disulfide films, with control over the layer number, on insulating substrates using gas phase sulfuric precursor (H2S) metal source. The thickness was varied to effectively number of layers (2 12) present in synthesized film. films were grown wafer-scale Si/SiO2 or quartz displayed excellent uniformity high crystallinity entire area. Thin film transistors prepared these materials, performances devices tested. an on/off...
A novel multibit MoS2 photoelectronic nonvolatile memory device is developed by synergistically combining rational designs and the efficient transfer of large-area flakes. The exhibits excellent characteristics, including a large programming/erasing current ratio that exceeds 107 , multilevel data storage 3 bits (corresponding to eight levels), performance stability over 200 cycles, stable retention 104 s.
Always wear a coat: On plastic substrate graphene is coated with conducting polymer (PEDOT), resulting in flexible composite film. The film used as counter electrode dye-sensitized solar cells (DSSCs) instead of platinum/transparent oxides (TCOs). performance the TCO- and platinum-free rivals that convenential DSSCs.
In the present work, type I, II, and III heterostructures are constructed with same base material using three representative functionalized monolayer scandium carbides (Sc2CF2, Sc2C(OH)2, Sc2CO2) by first-principles calculations based on density functional theory. contrast to general bilayer heterosystems composed of two-dimensional semiconductors, I heterojunctions obtained in one Sc2CF2/Sc2CO2 system remains Sc2C heterostructures, respectively. It is noteworthy that Sc2CF2 Sc2CO2...
We studied the surface-enhanced Raman scattering of an organic fluoropore (Rhodamine 6G, R6G) monolayer adsorbed onto graphene and two-dimensional (2D) molybedenium disulfides (MoS2) phototransistors compared results with R6G on 2D tungsten diselenides system (WSe2). The enhancement factor film WSe2 was comparable to corresponding value at 1365 cm–1 approximately twice this 615 cm–1. amplitude charge transfer estimated in situ by measuring photocurrent produced a hybrid consisting...
We demonstrate low-temperature growth and direct transfer of graphene–graphitic carbon films (G–GC) onto plastic substrates without the use supporting materials. In this approach, G–GC were synthesized on copper layers by using inductively coupled plasma enhanced chemical vapor deposition, enabling few-layer graphene (G) top Cu additional graphitic (GC) above layer at temperatures as low 300 °C. The patterned are not easily damaged or detached from polymer during wet etching process because...
The advantages of graphene photodetectors were utilized to design a new multifunctional optoelectronic device. Organic semiconductors, gold nanoparticles (AuNPs), and combined fabricate photodetecting device with nonvolatile memory function for storing photonic signals. A pentacene organic semiconductor acted as light absorption layer in the provided high hole photocurrent channel. AuNPs, positioned between tunneling blocking dielectric layers, both charge trap plasmonic scatterer, which...
We introduce an amorphous indium-gallium-zinc-oxide (a-IGZO) heterostructure phototransistor consisting of solution-based synthetic molybdenum disulfide (few-layered MoS2, with a band gap ∼1.7 eV) and sputter-deposited a-IGZO (with ∼3.0 films as novel sensing element broad spectral responsivity. The MoS2 serve visible light-absorbing layer high mobility channel layer, respectively. Spectroscopic measurements reveal that appropriate alignment at the heterojunction provides effective transfer...
Preventing reactive gas species such as oxygen or water is important to ensure the stability and durability of organic electronics. Although inorganic materials have been predominantly employed protective layers, their poor mechanical property has hindered practical application flexible The densely packed hexagonal lattice carbon atoms in graphene does not allow transmission small molecules. In addition, its outstanding flexibility optical transmittance are expected be useful overcome...
Differentiation of prohaemocytes, the precursors Drosophila blood cells (haemocytes), and release haemocytes from lymph gland, a major larval haematopoietic organ, are vital responses to wasp infestation or tissue degeneration. While extracellular matrices (ECMs) in gland play crucial role haemocyte differentiation, underlying mechanisms remain unclear. Here, we show that matrix glycoprotein Papilin (Ppn) is essential for maintaining prohaemocyte population glands. In Ppn-depleted larvae,...
Due to its high electrical conductivity and excellent transmittance at terahertz frequencies, graphene is a promising candidate as transparent electrodes for devices. We demonstrate liquid crystal based phase shifter with the films electrodes. The maximum shift 10.8 degree saturation voltage 5 V 50 um cell. frequencies depending on number of layer are also investigated. proposed provides continuous tunability, fully controllability, low DC operation.
In the present paper, band gap characteristics of oxygen functionalized-monolayer scandium carbide (monolayer Sc2CO2) under a perpendicular external electric field (E-field) were studied using DFT calculations for potential application MXene in optoelectronic and optical nanodevices. contrast to general pristine single-layer materials an E-field, monolayer Sc2CO2 undergoes indirect direct transition positive value changes sharply after transition. Remarkable variations properties are induced...
Tunability of the surface plasmon resonance wavelength is demonstrated by varying thickness Al2O3 spacer layer inserted between graphene and nanoparticles. By from 0.3 to 1.8 nm, shifted 583 566 nm. The shift due a change in electromagnetic field coupling strength localized plasmons excited gold nanoparticles single film. In contrast, when film absent system, no noticeable observed upon thickness.
We investigated, for the first time, photoresponse characteristics of solution-synthesized MoS2 phototransistors. The phototransistor was solely determined by interactions photogenerated charge carriers with surface adsorbates and interface trap sites. Instead contributing to photocurrent, illumination-generated electron-hole pairs were captured in sites (surface sites) due low carrier mobility MoS2. holes discharged ions (oxygen and/or water) adsorbed onto released as neutral molecules. At...