A5028129751- Organic Electronics and Photovoltaics
- GaN-based semiconductor devices and materials
- Conducting polymers and applications
- Organic Light-Emitting Diodes Research
- Semiconductor materials and interfaces
- Semiconductor materials and devices
- Thin-Film Transistor Technologies
- Analytical Chemistry and Sensors
- Molecular Junctions and Nanostructures
- ZnO doping and properties
- Luminescence and Fluorescent Materials
- CCD and CMOS Imaging Sensors
- Nanowire Synthesis and Applications
- Perovskite Materials and Applications
- Microstructure and Mechanical Properties of Steels
- Ga2O3 and related materials
- Metal and Thin Film Mechanics
- Copper Interconnects and Reliability
- Advanced Sensor and Energy Harvesting Materials
- Quantum Dots Synthesis And Properties
- Welding Techniques and Residual Stresses
- Hydrogen embrittlement and corrosion behaviors in metals
- Transition Metal Oxide Nanomaterials
- Gas Sensing Nanomaterials and Sensors
- Anodic Oxide Films and Nanostructures
Samsung (South Korea)
2013-2025
Government of the Republic of Korea
2016
Imperial College London
2009-2013
SAIT Polytechnic
2013
Seoul National University
2006-2010
Gwangju Institute of Science and Technology
2003-2005
Pohang Iron and Steel (South Korea)
2003
Yonsei University
2001
An effective method for reducing interelectrode shorting in silver nanowire (AgNW) based organic solar cells is reported. The applied to standard and inverted devices on poly(3-hexylthiophene) [6,6]-phenyl-C61-butyric acid methyl ester. best results are obtained using an architecture with a 200 nm buffer layer of nanostructured titania (TiOx) top the AgNWs, yielding power conversion efficiencies up 3.5%.
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication the EditorNEXTIndacenodithiophene-co-benzothiadiazole Copolymers for High Performance Solar Cells or Transistors via Alkyl Chain OptimizationHugo Bronstein†, Dong Seok Leem†, Richard Hamilton‡, Paul Woebkenberg†, Simon King†, Weimin Zhang†, Raja Shahid Ashraf†, Martin Heeney†, Thomas D. Anthopoulos†, John de Mello†, and Iain McCulloch*†View Author Information† Department of Chemistry, Centre Plastic Electronics, Imperial...
Complementary metal-oxide-semiconductor (CMOS) colour image sensors are representative examples of light-detection devices. To achieve extremely high resolutions, the pixel sizes CMOS must be reduced to less than a micron, which in turn significantly limits number photons that can captured by each using silicon (Si)-based technology (i.e., this reduction size results loss sensitivity). Here, we demonstrate novel and efficient method increasing sensitivity resolution superposing an organic...
Abstract To achieve high detectivity in infrared detectors, it is critical to reduce the device noise. However, for non-crystalline semiconductors, an essential framework missing understand and predict effects of disorder on dark current. This report presents experimental modeling studies noise current exemplar organic bulk heterojunction photodiodes, with 10 donor–acceptor combinations spanning wavelength between 800 1600 nm. A significant reduction higher were found devices using...
Abstract There remains a critical need for large‐area imaging technologies that operate in the shortwave infrared spectral region. Upconversion imagers combine photo‐sensing and display compact structure are attractive since they avoid costly complex process of pixilation. However, upconversion device research is primarily focused on optical output, while electronic signals from imager remain underutilized. Here, an organic efficient both readouts, extending capability human machine vision...
The authors report a promising metal oxide-doped hole transporting layer (HTL) of rhenium oxide (ReO3)-doped N,N′-diphenyl-N,N′-bis (1,1′-biphenyl)-4,4′-diamine (NPB). tris(8-hydroxyquinoline) aluminum-based organic light-emitting diodes with ReO3-doped NPB HTL exhibit driving voltage 5.2–5.4V and power efficiency 2.2–2.3lm∕W at 20mA∕cm2, which is significantly improved compared to those (7.1V 2.0lm∕W, respectively) obtained from the devices undoped NPB. Furthermore, device reveals prolonged...
Semiconducting silaindacenodithiophene polymers have been synthesized and their semiconducting properties reported. These with low-lying LUMO energy levels exhibit excellent ambipolar behavior in field-effect transistors both hole electron mobilities of greater than 0.1 cm2/(V s) recorded, high power-conversion efficiencies 4% solar cell devices.
Inverted bulk heterojunction solar cells are fabricated using a conjugated polyelectrolyte (PFN) as cathode interlayer. Enhanced photovoltaic performance is achieved by adjusting the PFN thickness. Measurements of optical transmittance, work function (via UPS) and surface atomic composition XPS) provide insights into this optimization. Drift-diffusion simulations point to reduction in recombination holes at main cause for improving Voc.
Interlayer lithography is used to pattern highly conductive, solution-processed, reduced graphene oxide source and drain electrodes down 10 μm gaps. These patterned allow for the fabrication of high-performance organic thin-film transistors complementary circuits. The method offers a viable route towards electronics fabricated entirely by solution processing.
Green-sensitive organic photodetectors (OPDs) with high sensitivity and spectral selectivity using boron subphthalocyanine chloride (SubPc) derivatives are reported. The OPDs composed of SubPc dicyanovinyl terthiophene derivative (DCV3T) demonstrated the highest green-sensitivity maximum external quantum efficiency (EQE) 62.6 % at an applied voltage -5 V, but wide full-width-at-half-maximum (FWHM) 211 nm. optimized performance considering was achieved from composition N,N-dimethyl...
There are growing opportunities and demands for image sensors that produce higher-resolution images, even in low-light conditions. Increasing the light input areas through 3D architecture within same pixel size can be an effective solution to address this issue. Organic photodiodes (OPDs) possess wavelength selectivity allow advancements regard. Here, we report on novel push-pull D-π-A dyes specially designed Gaussian-shaped, narrow-band absorption high photoelectric conversion. These p-type...
GaAs nanowires were epitaxially grown on Si(001) and Si(111) substrates by using Au-catalyzed vapor-liquid-solid (VLS) growth in a solid source molecular beam epitaxy system. Scanning electron microscopy analysis revealed that almost all the along <111> directions both Si for conditions investigated. The had very uniform diameter direction. X-ray diffraction data transmission GaAs<111> mixed crystal structure of hexagonal wurtzite cubic zinc-blende. Current-voltage characteristics junctions...
We investigated the effectiveness of p-dopants to generate holes in a hole transporting material by comparing absorption visible-near-infrared and infrared regions current density-voltage characteristics. CuI, MoO3, ReO3 having different work functions were doped organic material, 4,4′,4″-tris(N-(2-naphthyl)-N-phenylamino)-triphenylamine (2TNATA). Formation charge transfer (CT) complexes increases linearly with increasing doping concentration for all dopants. Dopants higher function...
High quality interconnection units (ICUs) with a high transparency and superior charge generating capability for tandem organic light-emitting diodes (OLEDs) are developed. The ICUs of rubidium carbonate-doped 4,7-diphenyl-1,10-phenanthroline/rhenium oxide (ReO3)-doped N,N′-diphenyl-N,N′-bis(1,1′-biphenyl)-4,4′-diamine layers or without an additional ReO3 interlayer produce transmittance (88%–92% at 420–700nm) spontaneous internal generation properties. A very efficiency ∼129cd∕A has been...
We report green-sensitive organic photodetectors consisting of a bulk heterojunction blend N,N-dimethylquinacridone and dicyanovinyl-terthiophene. Devices incorporating triphenylamine derivative-based electron blocking layer molybdenum oxide hole extracting lead to significantly low dark currents (Jd) ∼ 6.41 nA/cm2 at −3 V high external quantum efficiency 55.2% 540 nm wavelength with narrow full width half maximum 146 nm, which is likely be applicable for colour image sensors. Based on the...
Abstract Detection of light in the near‐infrared (NIR) and shortwave infrared (SWIR) spectral range is essential for wide practical applications biometrics, surveillance, machine vision, etc., which organic molecules have gained growing interest as potential sensing materials. In this study, newly synthesized donor–acceptor type copolymers consisting [1,2,5]thiadiazolo[3,4‐g]quinoxaline core unit with phenyl pendant groups acceptor thiophene donor achieving high‐efficiency SWIR...
The reverse transformation mechanism of martensite to austenite and the volume fraction retained have been studied in an Fe-3Si-13Cr-7Ni (wt-%) martensitic stainless steel by means dilatometry, transmission electron microscopy X-ray diffraction. Below a heating rate 10 K s-1, α' γ occurs diffusion, whereas it diffusionless shear above s-1. After reversion treatment at low temperatures, filmlike is observed along lath boundaries, while high temperatures produces granular inside laths addition...
Two novel dipolar donor–acceptor molecules approaching the cyanine limit were used for green-light-selective OPDs.
The dynamic characterization of two green-sensitive organic photodetectors (OPDs) using nonfullerene small molecules is investigated by analyzing the electrical parameters based on experimental results and simulated data. OPDs comprise N,N-dimethyl quinacridone (DMQA) as common donor dibutyl-substituted dicyanovinyl terthiophene (DCV3T) or boron-subphthalocyanine chloride (SubPc) respective acceptors. At applied voltage −5 V, device composed DMQA/SubPc shows a higher frequency response at...
We have investigated an Mg-doped In/sub x/O/sub y/(MIO)-Ag scheme for the formation of high-quality ohmic contacts to p-type GaN flip-chip light-emitting diodes (LEDs). The as-deposited sample shows nonlinear current-voltage (I--V) characteristics. However, annealing at temperatures 330/spl deg/C-530/spl deg/C 1 min in air ambient results linear I--V behaviors, producing specific contact resistances 10/sup -4/--10/sup -5/ /spl Omega//spl middot/cm/sup 2/. In addition, blue LEDs fabricated...
We have investigated Ag-indium tin oxide (ITO) scheme for obtaining high-quality p-type ohmic contacts GaN-based light-emitting diodes (LEDs). The Ag(1 nm)-ITO(200 nm) exhibit greatly improved electrical characteristics when annealed at temperatures in the range 400/spl deg/C-600/spl deg/C 1 min air, yielding specific contact resistances of /spl sim/10/sup -4/ Omega//spl middot/cm/sup 2/. In addition, give transmittance about 96% 460 nm, which is far better than that conventionally used...