A5102879355- Organic Electronics and Photovoltaics
- Microwave and Dielectric Measurement Techniques
- Conducting polymers and applications
- Electromagnetic Compatibility and Measurements
- Thin-Film Transistor Technologies
- Microwave Engineering and Waveguides
- Organic Light-Emitting Diodes Research
- Perovskite Materials and Applications
- Phase-change materials and chalcogenides
- Photorefractive and Nonlinear Optics
- Antenna Design and Analysis
- Antenna Design and Optimization
- Advanced Sensor and Energy Harvesting Materials
- Synthesis and Catalytic Reactions
- Electromagnetic Compatibility and Noise Suppression
- Advanced Electrical Measurement Techniques
- Advanced Optical Imaging Technologies
- Millimeter-Wave Propagation and Modeling
- Advanced Antenna and Metasurface Technologies
- Chemical Synthesis and Analysis
- Organic and Molecular Conductors Research
- Hydraulic and Pneumatic Systems
- Refrigeration and Air Conditioning Technologies
- Molecular Junctions and Nanostructures
- Sensor Technology and Measurement Systems
Samsung (South Korea)
2015-2024
Korea Research Institute of Standards and Science
2012-2022
Suwon Research Institute
2018-2019
Government of the Republic of Korea
2016-2019
Cornell University
2006
Kwangwoon University
2002-2004
Purdue University West Lafayette
2003
Pohang University of Science and Technology
1998-2002
Hanyang University
2001
We present the synthesis, characterization, and structural analysis of a thiophene-rich heteroacene, dibenzothiopheno[6,5-b:6',5'-f]thieno[3,2-b]thiophene (DBTTT) as well its application in field-effect transistors. The design DBTTT is based on enhancement intermolecular charge transfer through strong S-S interactions. Crystal structure showed that π-π distance shortened packing density higher than those electronically equivalent benzene analogue,...
A bulk-heterojunction (BHJ) blend is commonly used as the photoactive layer in organic photodetectors (OPDs) to utilize donor (D)/acceptor (A) interfacial energetic offset for exciton dissociation. However, this strategy often complicates optimization procedures, raising serious concerns over device processability, reproducibility, and stability. Herein, highly efficient OPDs fabricated with single-component semiconductors are demonstrated via solution-processing. The non-fullerene acceptors...
Stable uniform performance inkjet-printed polymer transistor arrays, which allow demonstration of flexible full-color displays, were achieved by new ambient processable conjugated copolymer semiconductor, and OTFT devices incorporating this material showed high mobility values > 1.0 cm2 V-1s–1. Bias-stress stability the was improved with a channel-passivation layer, suppresses density trap states at channel interface. As service to our authors readers, journal provides supporting information...
The control of molecular orientation and ordering liquid crystal (LC) organic semiconductor (OSC) for high-performance thermally stable thin-film transistors is investigated. A crystalline molecule, 2-(4-dodecyl thiophenyl)[1]dibenzothiopheno[6,5-b:6′,5′-f]-thieno[3,2-b]thiophene (C12-Th-DBTTT) synthesized, showing the highly ordered smectic X (SmX) phase, demonstrating reorganization via thermal annealing. resulting evaporated polycrystalline film solution-sheared thin show high charge...
The influence of alkyl side chains on the crystallinity semiconducting copolymer films and their sub-bandgap density-of-states (DOS), latter being closely related to stability device performance organic field-effect transistors (OFETs), is investigated. Three different poly(hexathiophene-alt-bithiazole) (PHTBTz) based polymer semiconductors, with identical backbones but chain positions lengths, were synthesized. examined by grazing incidence X-ray diffraction (GIXRD) strongly depends number,...
A solution-processable organic–inorganic hybrid material composed of a polysiloxane urethane acrylate composite (PSUAC) was developed through dual cross-linking mechanism and satisfies all the requirements for use as gate dielectric flexible organic thin-film transistors (OTFTs).
A novel green-absorbing organic molecule featuring dual intramolecular chalcogen bonds is synthesized and characterized. This incorporates two such bonds: one between a tellurium atom the oxygen of carbonyl moiety, other adjacent nitrogen within pyridine moiety. The molecule, exhibits narrow absorption spectrum elevated coefficients, closely aligned with resonance parameter approximately 0.5. behavior due to its cyanine-like characteristics favorable electrical properties, which are direct...
A new π-conjugated polymer, poly(2,5-dioctyloxyphenylene vinylene-alt-3,3-dioctylquater thiophene) (PPVQT-C8), consisting of alternating p-divinylene phenylene and 3,3-dialkylquater thiophene units, was synthesized for use in organic solar cell devices. The crystallinity poly(quaterthiophenes) (PQTs) reduced by introducing units between pairs quaterthiophene units. well-mixed nanoscale morphology PPVQT-C8:PCBM photoactive layer resulted from this modification, which increased the power...
We report on an enhanced electrical stability of organic thin-film transistors (OTFTs), where semiconductor (poly(didodecylquaterthiophene-alt-didodecylbithiazole) (PQTBTz-C12)) and a polymer insulator (poly(methyl methacrylate) (PMMA)) blended film were used as the active layer, in comparison with single PQTBTz-C12 OTFT. While both devices exhibit similar performance terms mobility ON/OFF ratios, device is less susceptible to OFF-bias stress. It suggested that carboxyl groups PMMA blend may...
Abstract The present work describes the development of an organic photodiode (OPD) receiver for high‐speed optical wireless communication. To determine optimal communication design, two different types photoelectric conversion layers, bulk heterojunction (BHJ) and planar (PHJ), are compared. BHJ‐OPD device has a −3 dB bandwidth 0.65 MHz (at zero bias) maximum 1.4 −4 V bias). A 150 Mbps single‐channel visible light (VLC) data rate using this by combining preequalization machine learning...
The interface between dielectric and organic semiconductor is critically important in determining thin-film transistor (OTFT) performance. Surface polarity of the layer can hinder charge transport characteristics, which has restricted utilization polymeric materials containing polar functional groups. Herein, electrical characteristics OTFTs are analyzed depending on alkyl chain length semiconductors surface polymer dielectrics. High-performance...
Abstract In order to fabricate polymer field‐effect transistors (PFETs) with high electrical stability under bias‐stress, it is crucial minimize the density of charge trapping sites caused by disordered regions. Here we report PFETs excellent comparable that single‐crystalline organic semiconductors specifically controlling molecular weight (MW) donor‐acceptor type copolymer semiconductors, poly (didodecylquaterthiophene‐ alt ‐didodecylbithiazole). We found MW‐induced thermally structural...
A series of amorphous polymers poly(arylenevinylene) copolymers, in which heterocycles (furan, thiophene, selenophene) and dialkoxy phenylenes were alternatingly linked by vinylene unit, was prepared the Horner−Emmons reaction. Because high regularity polymer microstructure selective formation E olefin, resulting showed good interchain π−π stacking thin film state despite being polymers. When A,B-alternating poly(phenylene thiophene vinylene), particular with bis(heptoxy) group, used as a...
In this study, high-performance organic photodetectors are presented which utilize a pristine chlorinated subphthalocyanine photoactive layer. Optical and optoelectronic analyses indicate that the device photocurrent is primarily generated through direct charge generation within layer, rather than exciton separation at layer interfaces. Molecular modelling suggests facilitated by high octupole moment (-80 DÅ2), generates 200 meV shift in molecular energetics. Increasing thickness of leads to...
Abstract Phenyl‐substituted heteroacene, diphenyl‐dibenzothiopheno[6,5‐ b :6′,5′‐ f ]thieno[3,2‐ ]thiophene (DPh‐DBTTT), is introduced as a thermally durable high‐performance organic semiconductor. The DPh‐DBTTT single crystals exhibit hole mobility up to 31.9 cm 2 V −1 s , and the vacuum‐deposited thin‐film transistors show maximum of 6.32 . X‐ray crystallographic analysis reveals that small tilting angle between phenyl substituent DBTTT core reduces reorganization energy dramatically....
This paper reports a polymeric gate insulating material of poly(hydroxy imide) cured at the low temperature 130 °C for application to organic thin-film transistors on plastic substrates exhibiting high breakdown voltage and no hysteresis.
Abstract Organic semiconductors with distinct molecular properties and large carrier mobilities are constantly developed in attempt to produce highly‐efficient electronic materials. Recently, designer molecules unique structural modifications have been expressly suppress motions the solid state that arise from low‐energy phonon modes, which uniquely limit through electron–phonon coupling. However, such low‐frequency vibrational dynamics often involve complex dynamics, making comprehension of...
This paper investigates the pressure pulsations caused by each mass flow rate through suction valves and ports of a multicylinder compressor in order to attribute high-pressure pulsation responses certain valves. By staggering valve configurations appropriately, it is shown that level gas manifold automotive can be reduced. First, equation for compression cycle, Bernoulli-Euler linear differential beam valves, piston kinematics are considered calculate rates The then predicted based on...
A new reliable computational model to predict the hole mobility of poly-crystalline organic semiconductors in thin films was developed. Site energy differences and transfer integrals crystalline morphologies molecules were obtained from quantum chemical calculations, which periodic boundary conditions efficiently applied capture interactions with surrounding layer. Then parameters employed kinetic Monte Carlo (kMC) simulations estimate carrier mobility. Carrier transport multiple directions...
We propose dual-band filters made from a single-layer metasurface for operating on the 28 and 39 GHz bands in mm-wave fifth generation (5G) communication systems. use conformational space annealing method, global optimization technique, test usefulness of metasurfaces through design, fabrication, measurement with 2916 square-shaped pixels per unit cell defined single layer. Each pixel has only two states: either filled metal or free metal. were able to obtain transmissive capable performing...
The direct comparison technique using a transfer power standard with an adapter and its uncertainty are considered. A waveguide thermistor mount appropriate waveguide-to-coaxial serves new combined coaxial standard. In order to obtain the effective efficiency of standard, phase as well magnitude scattering parameters have be known. Consequently, give rise additional technique. this paper, K-band WR42-2.4-mm is used calibrate 2.4-mm sensor. Measurement results presented evaluated 2.5 % (k=2)...
A measurement system for a millimeter-wave (mm-wave) antenna is presented here. The topologies of RF subsystems measurements are reviewed, and the optimum topology far-field range mm-wave antennas proposed. This minimizes losses both Tx local oscillator (LO) signal paths. In order to verify proposed topology, W-band fully anechoic chamber 10 (W) m × 13 (L) 7.5 (H) in size designed implemented. To provide optimal LO input power, test supply that compensates complicated path also optimization...