A5100430925- Luminescence and Fluorescent Materials
- Organic Electronics and Photovoltaics
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Organic Light-Emitting Diodes Research
- Perovskite Materials and Applications
- Porphyrin and Phthalocyanine Chemistry
- Conducting polymers and applications
- biodegradable polymer synthesis and properties
- Organic and Molecular Conductors Research
- Biopolymer Synthesis and Applications
- Molecular Sensors and Ion Detection
- Inorganic Chemistry and Materials
- Photochromic and Fluorescence Chemistry
- Nuclear and radioactivity studies
- Advanced Polymer Synthesis and Characterization
- Natural Fiber Reinforced Composites
- Luminescence Properties of Advanced Materials
- 2D Materials and Applications
- Polydiacetylene-based materials and applications
- Photoreceptor and optogenetics research
- Crystallography and molecular interactions
- Thin-Film Transistor Technologies
- Photochemistry and Electron Transfer Studies
- Graphite, nuclear technology, radiation studies
Seoul National University
2012-2021
We have rationally designed a densely packed 1:1 donor-acceptor (D-A) cocrystal system comprising two isometric distyrylbenzene- and dicyanodistyrylbenzene-based molecules, forming regular one-dimensional mixed stacks. The crystal exhibits strongly red-shifted, bright photoluminescence originating from an intermolecular charge-transfer state. peculiar electronic situation gives rise to high ambipolar p-/n-type field-effect mobility up 6.7 × 10(-3) 10(-2) cm(2) V(-1) s(-1), respectively, as...
We report on a molecularly tailored 1:1 donor-acceptor (D-A) charge-transfer (CT) cocrystal that manifests strongly red-shifted CT luminescence characteristics, as well noteworthy reconfigurable self-assembling behaviors. A loosely packed molecular organization is obtained consequence of the noncentrosymmetric chemical structure molecule A1, which gives rise to considerable free volume and weak intermolecular interactions. The stacking features complex result in an external...
A new 2:1 donor (D):acceptor (A) mixed-stacked charge-transfer (CT) cocrystal comprising isometrically structured dicyanodistyrylbenzene-based D and molecules is designed synthesized. Uniform 2D-type morphology manifested by the exquisite interplay of intermolecular interactions. In addition to its appealing structural features, unique optoelectronic properties are unveiled. Exceptionally high photoluminescence quantum yield (ΦF ≈ 60%) realized non-negligible oscillator strength S1...
Solid-state, luminescent, aggregation-induced enhanced emission (AIEE)-active dicyanodistyrylbenzene-based organic π-conjugated materials, i.e. α-MODCS, α-MODBDCS, β-MODCS, and β-MODBDCS, are designed. In virtue of the systematically substituted modular molecular systems combined with thorough structural analyses, photophysical studies, electronic structure calculations, spontaneous stimulated properties quantified rationalized from a perspective well-established structure–property...
J-aggregation has been shown to be beneficial for light amplification in single crystals of π-conjugated organic molecules. In the case H-aggregation, criteria such processes are still under debate. It also that H-aggregate arrangements with considerable π–π overlap detrimental amplification. We show here a proper alignment molecules crystal lattice, which minimizes between adjacent molecules, gives rise (random) stimulated emission from cofacial similar herringbone aggregates.
High-performance n-type organic field-effect transistors (OFETs) based on 2-dimensional (2D) crystalline layered films of the novel dicyanodistyrylbenzene (DCS) derivative (2Z,2′Z)-3,3′-(1,4-phenylene)bis(2-(3,5-bis(trifluoromethyl)phenyl)acrylonitrile) (CN-TFPA) were fabricated using a simple solution process. The OFETs showed electron mobilities up to 0.55 cm2 V–1 s–1, which was attributed appropriate affinity and dense molecular packing in well-ordered 2D terrace structure. Because easy...
Intermolecular interactions are decisive in controlling optoelectronic properties of molecular materials. Polymorphism one and the same material gives a unique opportunity to gain direct insight into intermolecular contributions. Here, stimulated emission two polymorphs dicyanodistyrylbenzene derivative with multiple trifluoromethyl groups terminal rings investigated, correlated arrangement resulting excitonic coupling. The have distinctly different behavior emitting blue, while other emits...
Combined structural, photophysical, and quantum-chemical studies at the quantum mechanics/molecular mechanics (QM/MM) level precisely reveal structure-property relationships in a mixed-stack donor-acceptor cocrystal, which displays vibronically structured fluorescence, strongly red-shifted against spectra of parent donor acceptor, with high yield despite pronounced CT character emitting state. The study elucidates reasons for this unusual combination, quantifies ordering nature collective...
In this work, a simple but effective molecular design strategy is developed for the generation of intense blue emission in solid state including single crystals through multiple secondary intermolecular interactions such as CF…HC hydrogen bonding. The synthesized novel imidazole‐based excited‐state intramolecular proton transfer (ESIPT) molecule, 2‐(1‐(3,5‐bis(trifluoromethyl)phenyl)‐4,5‐diphenyl‐1H‐imidazol‐2‐yl)phenol (HPI‐CF 3 ), shows significantly enhanced fluorescence crystal (Φ F =...
Highly fluorescent excited‐state charge‐transfer complexes (exciplexes) formed at the interfacial region between a polymeric donor matrix, here, poly( N ‐vinylcarbazole), and embedded nanostructured acceptors are characterized for their photophysical properties. Exciplex‐to‐exciton emission switching is observed after solvent vapor annealing (SVA) due to size evolution of nanostructures beyond exciton diffusion length. Color‐tunable exiplex (sky blue, green, orange) demonstrated three...
Submillimeter sized n-channel organic single crystalline nanosheet based on dicyanodistyrylbenzene derivative, (2E,2′E)-3,3′-(2,5-dimethoxy-1,4-phenylene)bis(2-(5-(4-(trifluoromethyl)phenyl)thiophen-2-yl)acrylonitrile) (Me-4-TFPTA), is developed. Strong π–π interaction, hydrogen bonding interactions derived from cyano group (CN) as well solvent inclusion along the lateral direction play a key role in forming morphology. Me-4-TFPTA nanosheets exhibit excellent field-effect electron mobility...
Abstract We report on a molecularly tailored 1:1 donor–acceptor (D‐A) charge‐transfer (CT) cocrystal that manifests strongly red‐shifted CT luminescence characteristics, as well noteworthy reconfigurable self‐assembling behaviors. A loosely packed molecular organization is obtained consequence of the noncentrosymmetric chemical structure molecule A1 , which gives rise to considerable free volume and weak intermolecular interactions. The stacking features complex result in an external...
Abstract Polymorphs of organic semiconductors are great interest as they shed light to structure‐property relationships. The full X‐ray thin film structure analysis two polymorphs (B, G) an important n‐type semiconducting dicyano‐distyrylbenzene based small molecule (CN‐TFPA) is reported. Drastically different structures the monotropic phases revealed, that uncommon 2D crossed π‐stacked arrangement for B‐phase versus a 1D slipped π‐stack G. Both exhibit layered in (100) plane with high...
Abstract 2D single crystals of down to two‐monolayer thickness are fabricated from a push–pull structure‐based green light absorbing organic n‐type semiconductor, (2 E ,2′ )‐3,3′‐(2,5‐difluoro‐1,4‐phenylene)bis(2‐(5‐(4‐(trifluoromethyl)phenyl)thiophen‐2‐yl)acrylonitrile) (2F‐4‐TFPTA). The 2F‐4‐TFPTA crystal exhibits field‐effect electron mobility 0.9 cm 2 V −1 s in the dark and also decent photoresponsivity 3.6 × 10 3 A W under light‐emitting diode irradiation, which is noted as first...
Charge-transfer (CT) crystals show unique transport and emission properties which are substantially different from those of individual electron donor (D) acceptor (A) molecules constituting them. While the CT well established as to enable interpretation prediction their electrical properties, photophysical processes—particularly emission–structure relationship in crystals—are much less explored; this is because often weak photoluminescence (PL), attributed small oscillator strength (f)...
Photo-functional infinite coordinated polymers (ICPs) were synthesized that consist of the photochromic dithienylethene (DTE) and a luminescent bridging unit to give enhanced fluorescence in solid state. We could fabricate well-ordered micropatterns these ICPs by soft-lithographic method, which repeatedly showed high contrast on-off switching.
The highly luminescent dicyanodistyrylbenzene-based charge-transfer (CT) cocrystal based on isometric donor and acceptor molecules with a mixing ratio of 2:1 is characterized in the thin film regime. Physical vapor deposited films prepared at different substrate temperatures are analyzed terms their structure transistor performance. morphologies crystallographic properties including microstrain mosaic spread strongly dependent temperature. Enhanced crystal growth rising leads to better...
S. Y. Park and co-workers demonstrate a novel effective method to achieve highly efficient color-tuned (sky blue, green, orange) exciplex emissions originating from the nanoscale interface between polymeric donor—poly(N-vinylcarbazole) (PVK)—and fluorescent nanostructured acceptors. An unprecedented approach obtain white-emitting PVK film consisting of multiple is also presented. Exciplex-to-exciton emission color switching due size evolution acceptors demonstrated photophysically interpreted.
An incineration treatment of inflammable radioactive wastes leads to have a reduction effect disposal cost and also contribute an enhancement safety at site by taking the advantage stabilization which is accomplished converting organic materials into inorganic materials. As it was required for technology, KAERI (Korea Atomic Energy Research Institute) has developed pilot process then constructed demonstration facility having based on operating experiences process. In this study, worker...