A5084525096- Organic Electronics and Photovoltaics
- Conducting polymers and applications
- Perovskite Materials and Applications
- Organic Light-Emitting Diodes Research
- Korean Urban and Social Studies
- Molecular Junctions and Nanostructures
- Luminescence and Fluorescent Materials
- Fullerene Chemistry and Applications
- Parallel Computing and Optimization Techniques
- Advanced Data Storage Technologies
- Subtitles and Audiovisual Media
- Thin-Film Transistor Technologies
- Cloud Computing and Resource Management
- EFL/ESL Teaching and Learning
- Semiconductor Lasers and Optical Devices
- Chalcogenide Semiconductor Thin Films
- Tunneling and Rock Mechanics
- Ocular Surface and Contact Lens
- Blood disorders and treatments
- Engineering Applied Research
- Advanced Surface Polishing Techniques
- Pneumocystis jirovecii pneumonia detection and treatment
- Photonic and Optical Devices
- GaN-based semiconductor devices and materials
- Multimedia Communication and Technology
Chungnam National University
2020-2025
University of California, Santa Barbara
2018-2024
Korea University
2020-2024
Swiss Federal Institute of Metrology
2023
Chungbuk National University
2023
Associació de la Paràlisi Cerebral
2023
Stockholm University
2022-2023
DigitalSpace (United States)
2023
Seoul National University
2003-2021
Government of the Republic of Korea
2016-2021
Abstract Sensitive detection of near‐infrared (NIR) light enables many important applications in both research and industry. Current organic photodetectors suffer from low NIR sensitivity typically due to early absorption cutoff, responsivity, and/or large dark/noise current under bias. Herein, based on a novel ultranarrow‐bandgap nonfullerene acceptor, CO1‐4Cl, are presented, showcasing remarkable responsivity over 0.5 A W −1 the spectral region (920–960 nm), which is highest among...
The impact of gate metals on the threshold voltage <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$(V_{\rm TH})$</tex> </formula> and current p-GaN high-electron-mobility transistors (HEMTs) is investigated by fabricating HEMTs with different work function metals—Ni W. incorporate a layer under electrode as stack top AlGaN/GaN layer. In comparison to Ni-gate HEMTs, W-gate showed higher...
Herein, a facile and effective strategy is demonstrated to unleash the full potential of existing photoactive materials.
Narrow bandgap n-type molecular semiconductors are relevant as key materials components for the fabrication near-infrared organic solar cells (OSCs) and photodetectors (OPDs). We thus designed nearly isostructural nonfullerene electron acceptors, except choice of solubilizing units, which absorb from 600 to 1100 nm. Specific molecules include CTIC-4F, CO1-4F, COTIC-4F, whose optical bandgaps 1.3, 1.2, 1.1 eV, respectively. Modulation intramolecular charge transfer characteristics was...
Narrow-bandgap polymer semiconductors are essential for advancing the development of organic solar cells. Here, a new narrow-bandgap acceptor L14, featuring an acceptor-acceptor (A-A) type backbone, is synthesized by copolymerizing dibrominated fused-ring electron (FREA) with distannylated bithiophene imide. Combining advantages both FREA and A-A polymer, L14 not only shows narrow bandgap high absorption coefficient, but also low-lying frontier molecular orbital (FMO) levels. Such FMO levels...
A new 3D nonfullerene small-molecule acceptor is reported. The interlocking geometry of the enables uniform molecular conformation and strong intermolecular connectivity, facilitating favorable nanoscale phase separation electron charge transfer. By employing both a novel polymer donor in solution-processed organic solar cells, high-power conversion efficiency close to 6% demonstrated. As service our authors readers, this journal provides supporting information supplied by authors. Such...
We have studied the effects of hole transporting layers and electron on device efficiencies iridium(III) bis[(4,6-di-fluorophenyl)-pyridinato-N,C2′] picolinate (FIrpic) doped 3,5′−N,N′-dicarbazole-benzene (mCP) host blue phosphorescent organic light emitting diodes. found that efficiency is very sensitive to materials used both triplet energy carrier transport properties affect efficiency. On other hand, there no apparent correlation between material used. Instead, affected by mobility layer only.
We have demonstrated a substantial enhancement in the efficiency of iridium (III) bis[(4,6-di-fluorophenyl)-pyridinate-N,C2′]picolinate based blue phosphorescent organic light-emitting devices (PHOLEDs). The efficiencies PHOLEDs with conventional electron transport materials are low due to their mobilities as well triplet energies. High energy transporting material high mobility was used hole blocker achieve efficient exciton confinement and good charge balance device thereby achieving...
Abstract Two narrow bandgap non‐fullerene acceptors (NBG‐NFAs), namely, COTIC‐4F and SiOTIC‐4F, are designed synthesized for the fabrication of efficient near‐infrared organic solar cells (OSCs). The chemical structures NBG‐NFAs contain a D′‐D‐D′ electron‐rich internal core based on cyclopentadithiophene (or dithienosilole) (D) alkoxythienyl (D′) core, end‐capped with highly electron‐deficient unit 2‐(5,6‐difluoro‐3‐oxo‐2,3‐dihydro‐1H‐inden‐1‐ylidene)malononitrile (A), ultimately providing...
We report a significant improvement in the efficiency of deep-blue phosphorescent organic light-emitting devices based on electrophosphorescent dye bis(4′,6′-difluorophenylpyridinato)tetrakis (1-pyrazolyl) borate (FIr6). Using 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC) as hole transport layer (HTL), we achieved maximum external quantum ηEQE=(18±1)%, which is approximately 50% higher than ηEQE=12% previously reported device with bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl HTL. The...
Abstract In this study, a comprehensive analytical model to quantify the total nongeminate recombination losses, originating from bimolecular as well bulk and surface trap‐assisted mechanisms in nonfullerene‐based heterojunction organic solar cells is developed. This proposed successfully employed obtain different contributions current of investigated under illumination intensities. Additionally, quantitatively describes experimentally measured open‐circuit voltage versus light intensity...
One-dimensional low bandgap polymer nanowires successfully incorporated into bulk-heterojunction organic solar cells, yielding a high PCE exceeding 10% with thick films.
Understanding the microstructures of semiconducting polymers is critical for improving charge transport properties polymer field-effect transistors (PFETs). A series diketopyrrolopyrrole-based copolymers designed by implementing concept intramolecular noncovalent conformational locks through functionalization backbones with fluorine atoms or methoxy groups were synthesized and compared their unfunctionalized analogue. In contrast to bimodal texture polymer, thin films exhibit predominantly...
Abstract A series of narrow bandgap electron acceptors is designed and synthesized for efficient near‐infrared (NIR) organic solar cells. Extending π‐conjugation donor frameworks leads to an intense intramolecular charge transfer, resulting in broad absorption profiles with band edge reaching 950 nm. When blended polymer PTB7‐Th, IOTIC‐2F exhibits transfer even a small energetic offset, so as achieve large photogenerated current over 22 mA cm −2 energy losses (≈0.49 eV) cell devices. With...
Abstract Even though significant breakthroughs with over 18% power conversion efficiencies (PCEs) in polymer:non‐fullerene acceptor (NFA) bulk heterojunction organic solar cells (OSCs) have been achieved, not many studies focused on acquiring a comprehensive understanding of the underlying mechanisms governing these systems. This is because it can be challenging to delineate device photophysics polymer:NFA blends comprehensively, and even more complicated trace origins differences subtle...
Continuously enhanced photoresponsivity and suppressed dark/noise current combinatorially lead to the recent development of high-detectivity organic photodetectors with broadband sensing competence. Despite achievements, reliable photosensing enabled by (OPDs) still faces challenges. Herein, we call for heed over a universal phenomenon detrimental sensitivity dark illumination history in high-performance inverted OPDs. The phenomenon, unfavorable attainment high consistent figures-of-merit,...
Abstract Hole‐transport layers (HTL) in perovskite solar cells (PSCs) with an n‐i‐p structure are commonly doped by bis(trifluoromethane)sulfonimide (TFSI) salts to enhance hole conduction. While lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) dopant is a widely used and effective dopant, it has significant limitations, including the need for additional solvents additives, environmental sensitivity, unintended oxidation, migration, which can lead lower stability of PSCs. A novel ionic...
We demonstrate high efficiency white organic light-emitting devices with two adjacent emissive layers each doped three phosphorescent emitters (blue, green, and red). Efficient charge exciton confinement is realized by employing transport triplet energy, leading to a maximum external quantum of (19±1)%. Using the p-i-n device structure, we have achieved peak power (40±2) lm/W (36±2) at 100 cd/m2, color rendering index 79, Commission Internationale de L’Eclairage coordinates (0.37, 0.40) for...
In this contribution, we studied the effects of 3D molecular geometry in non-fullerene solar cells based on perylene diimide small molecules.
A series of four polymers containing benzo[1,2‐b:4,5‐b′]dithiophene (BDT) and 5,6‐difluoro‐4,7‐diiodobenzo[c][1,2,5]thiadiazole (2FBT), PBDT2FBT, PBDT2FBT‐O, PBDT2FBT‐T, PBDT2FBT‐T‐O, are synthesized with their different side chains, alkyl‐, alkoxy‐, alkylthienyl‐, alkoxythienyl. Experimental results theoretical calculations show that the molecular tuning chains simultaneously influences solubilities, energy levels, light absorption, surface tension, intermolecular packing resulting by...
A donor-acceptor conjugated copolymer enables the formation of nanowire systems that can be successfully introduced into bulk-heterojunction organic solar cells. simple binary solvent mixture makes polarity control possible allows kinetic over self-assembly crystalline polymer a structure during film-forming process. The enhanced photoconductivity nanowire-embedded photoactive layer efficiently facilitates photon harvesting in resultant maximum power conversion efficiency is 8.2%...