A5073141466- Organic Light-Emitting Diodes Research
- Semiconductor materials and devices
- Organic Electronics and Photovoltaics
- Magnetic and transport properties of perovskites and related materials
- Luminescence and Fluorescent Materials
- Molecular Junctions and Nanostructures
- Advanced Condensed Matter Physics
- Surface Chemistry and Catalysis
- Advanced Chemical Physics Studies
- Conducting polymers and applications
- Nanocluster Synthesis and Applications
- Electronic and Structural Properties of Oxides
- Copper Interconnects and Reliability
- Multiferroics and related materials
- Computational Drug Discovery Methods
- Catalytic Cross-Coupling Reactions
- Spectroscopy and Quantum Chemical Studies
- X-ray Diffraction in Crystallography
- Carbon and Quantum Dots Applications
- Photochemistry and Electron Transfer Studies
- Crystallization and Solubility Studies
- Protein Structure and Dynamics
- Advancements in Photolithography Techniques
- Machine Learning in Materials Science
- Advanced NMR Techniques and Applications
Samsung (South Korea)
2015-2025
Hanyang University
2022
Suwon Research Institute
2016-2020
North Carolina State University
2010-2014
Seoul National University
2004-2011
Shandong University
2011
Ewha Womans University
2009-2010
Institut de Chimie de la Matière Condensée de Bordeaux
2010
Université de Bordeaux
2010
Centre National de la Recherche Scientifique
2010
Although the organic light-emitting diode (OLED) has been successfully commercialized, development of deep-blue OLEDs with high efficiency and long lifetime remains a challenge. Here, novel hyperfluorescent OLED that incorporates Pt(II) complex (PtON7-dtb) as phosphorescent sensitizer hydrocarbon-based multiple resonance-based fluorophore an emitter (TBPDP ν-DABNA) in device emissive layer (EML), is proposed. Such EML system can promote efficient energy transfer from triplet excited states...
Finding narrow-band, ultrapure blue thermally activated delayed fluorescence (TADF) materials is extremely important for developing highly efficient organic light-emitting diodes (OLEDs). Here, spin-vibronic coupling (SVC)-assisted emitters obtained by joining two carbazole-derived moieties at a para position of phenyl unit and performing substitutions using several blocking groups are presented. Despite relatively large singlet-triplet gap (∆EST ) >0.2 eV, triplet-to-singlet crossover can...
Achieving narrow-bandwidth emission and high external quantum efficiency (EQE) simultaneously is a challenge for next-generation blue-emitting organic light-emitting diodes (OLEDs). In this study, novel multiple-resonance thermally activated delayed fluorescence (MR-TADF) emitters are developed by fusing an indolocarbazole unit with two carbazole skeletons using para-oriented nitrogen atoms. The resulting rigid planar π-system without electron-accepting atoms exhibits pure blue...
We prepared BiOCl(1-x)Br(x) (x=0-1) solid solutions and characterized their structures, morphologies, photocatalytic properties by X-ray diffraction, diffuse reflectance spectroscopy, scanning electron microscopy, Raman photocurrent activity measurements also density functional theory calculations for BiOCl, BiOBr, BiOCl(0.5)Br(0.5). Under visible-light irradiation exhibits a stronger than do BiOCl with the reaching maximum at x=0.5 decreasing gradually as x is increased toward 1 or...
In order to establish the density and spatial distribution of charge carriers intrinsic $n$-type ${\text{LaAlO}}_{3}{\text{-SrTiO}}_{3}$ heterointerface, we carry out first-principles calculations on ${({\text{LaAlO}}_{3})}_{n}{({\text{SrTiO}}_{3})}_{15}$ slab model with $n=2--10$. As thickness ${\text{LaAlO}}_{3}$ layer increases, transfer from ${\text{SrTiO}}_{3}$ converges half an electron per two-dimensional unit cell. It is found that electrons in conduction band consist various types...
Abstract The discovery of high-performance functional materials is crucial for overcoming technical issues in modern industries. Extensive efforts have been devoted toward accelerating and facilitating this process, not only experimentally but also from the viewpoint design. Recently, machine learning has attracted considerable attention, as it can provide rational guidelines efficient material exploration without time-consuming iterations or prior human knowledge. In regard, here we develop...
The recently developed narrow-band blue-emitting organoboron chromophores based on the multiple-resonance (MR) effect have now become one of most important components for constructing efficient organic light emitting diodes (OLEDs). While they basically emit through fluorescence, are also known showing substantial thermally activated delayed fluorescence (TADF) even with a relatively large singlet–triplet gap (ΔEST). Indeed, understanding reverse intersystem crossing (RISC) dynamics behind...
With the advancements in deep learning, generative models combined with graph neural networks have been successfully employed for data-driven molecular generation. Early methods based on non-autoregressive approach effective generating graphs quickly and efficiently but suffered from low performance. In this paper, we present an improved learning method involving a variational autoencoder efficient generation manner. We introduce three additional objectives incorporate them into training of...
Abstract Much effort has been dedicated to increase the operational lifetime of blue phosphorescent materials in organic light‐emitting diodes (OLEDs), but reported device lifetimes are still too short for industrial applications. An attractive method increasing a given emitter without making any chemical change is exploiting kinetic isotope effect, where key CH bonds deuterated. A computer model identifies that most vulnerable molecular site an Ir‐phenylimidazole dopant benzylic bond and...
A novel boron complex bearing a pyrene ligand (CPB) was synthesized and introduced as the first example of binuclear in organic light-emitting diodes. In solid state, CPB2 exhibited strong red emission. devices, emission with Commission International de L'Eclairage (CIE) coordinates (0.57, 0.42) obtained by tuning weight concentration CPB2. behaved both an emitting electron transporting material.
Computationally predicting reverse intersystem crossing (RISC) rates is important for designing new thermally activated delayed fluorescence (TADF) materials. We report a method that can quantitatively predict RISC by explicitly considering the spin–vibronic coupling mechanism. The element of Hamiltonian obtained expanding spin–orbit and non-Born–Oppenheimer terms to second order then brought into Golden Rule rate under Condon approximation. equation solved directly in time domain using...
We report improved results of atomistic modeling V-Fe alloys. introduced an electronic structure embedding approach to improve the description point defects in first-principles calculations, by including semicore electrons some V atoms (those near interstitial where levels are broadened) but not those further from defect. This enables us combine good accuracy for defect within large supercells and expand data set calculations vanadium with without small amounts iron. Based on these data,...
Supramolecular interactions were studied in two planar model systems, 1,5- and 2,6-dibromoanthraquinones, prepared on Au(111) using scanning tunneling microscopy. In both we found rigid triangular structures that consisted of simultaneous halogen bonds hydrogen bonds, as reported protein−ligand complexes. We proposed molecular models well reproduced by first-principle studies could be explained bonds. The distances, angles, and, strengths the intermolecular measured observed structures,...
The structural, electrical, and optical properties of monolayer ruthenium oxide (RuO2) nanosheets (NSs) fabricated by chemical exfoliation a layered three-dimensional form K-intercalated RuO2 are studied systematically via experimental computational methods. Monolayer NS is identified as having distorted h-MX2 structure. This the first observation structure that unlike t-MX2 layers in parent material does not have hexagonal symmetry. NSs shown to transparency superior graphene, thereby...
Heterogeneity in intratumoral cancers leads to discrepancies drug responsiveness, due diverse genomics profiles. Thus, prediction of responsiveness is critical precision medicine. So far, prediction, drugs' molecular "fingerprints", along with mutation statuses, have not been considered. Here, we constructed a 1-dimensional convolution neural network model, DeepIC50, predict three classes, based on 27,756 features including statuses and various fingerprints. As result, DeepIC50 showed better...
Predicting drug response is critical for precision medicine. Diverse methods have predicted responsiveness, as measured by the half-maximal inhibitory concentration (IC50), in cultured cells. Although IC50s are continuous, traditional prediction models dealt mainly with binary classification of responsiveness. However, since there few regression-based IC50 predictions, comprehensive evaluations models, including machine learning (ML) and deep (DL), diverse data types dataset sizes, not been...
Abstract The excellent contrast ratio, visibility, and advantages in producing thin light displays let organic emitting diodes change the paradigm of display industry. To improve future technologies, higher electroluminescence efficiency is needed. Herein, detailed study non-radiative decay mechanism employing density functional theory calculations carried out a simple, general strategy for design ancillary ligand formulated. It shown that steric bulk properly directed towards...
Abstract Novel homoleptic cyclometalated Ir(III) complexes are designed to improve their emission dipole orientations in the emitting layer of blue phosphorescent organic light devices. Biphenyl group is introduced into imidazole simultaneously achieve enhanced efficiency and operation lifetime, resulting one best device performances single‐stacked diodes with 91% orientation, 26.3% maximum external quantum (maximally calculated as 41%), 169 h lifetime at 1000 cd m −2 (LT80), color...
Using the first-principles method, we investigate hydrogen adsorption on polar AlO2 surface of LaAlO3–SrTiO3 heterostructures with an n-type interface. It is found that H atom most stable when bound at O atom. The energy for a given density lowered (i.e., stronger binding) increasing LaAlO3 thickness. adsorbed donates electrons to conduction band SrTiO3, which results in metallic conductivity SrTiO3. charge transfer from SrTiO3 significantly alters electrostatic boundary condition and...
Magnetism of FeRh (001) films strongly depends on film thickness and surface terminations. While magnetic ground state bulk is G-type antiferromagnetism, the Rh-terminated exhibit ferromagnetism with strong perpendicular MCA whose energy +2.1 meV/$\Box$ two orders magnitude greater than 3$d$ metals, where $\Box$ area two-dimensional unit cell. Goodenough-Kanamori-Anderson rule superexchange interaction crucial in determining phases thin films, are results interplay competition between three...
Understanding the saturated vapor pressure (
This study combines machine learning potential and steered molecular dynamics to provide atomic-level understanding of the adhesion properties Ru/SiO 2 interfaces.
Abstract Thermally activated delayed fluorescence (TADF) has emerged as a promising and pragmatic light‐generation method for producing efficient organic light‐emitting diodes (OLEDs). However, the low operational stability associated with blue‐light TADF emitters is major drawback excited‐state molecular degradation process remains poorly understood. Archetypal are comprised of cycloamine donor aromatic acceptor moieties, corresponding C–N bond considered weakest link in structure....
A new ternary manganese vanadate, NaMnVO(4), was synthesized by solid state reaction route, and its crystal structure magnetic properties were characterized X-ray diffraction, susceptibility specific heat measurements, density functional calculations. NaMnVO(4) crystallizes in the maricite-type with space group Pnma, a = 9.563(1) A, b 6.882(1) c 5.316(1) Z 4. contains MnO(4) chains made up of edge-sharing MnO(6) octahedra, these are interlinked VO(4) tetrahedra. The has broad maximum at...