윤성준 교수

Understanding the role of self-assembly and electronic interactions of constituent molecules in determining optoelectronic properties of a molecular solid is a fundamental and essential issue in material science. Particularly, the correlation between the molecular stacking mode and modulated optical properties has barely been established in spite of its scientific and technological importance. Herein, we present dicyanodistyrylbenzene-based highly luminescent crystals which uniquely exhibit poly

Abstract A new dicyanodistyrylbenzene‐based phasmidic molecule, (2Z,2′Z)‐2,2′‐(1,4‐phenylene)bis(3‐(3,4,5‐tris(dodecyloxy)phenyl)acrylonitrile), GDCS, is reported, which forms a hexagonal columnar liquid crystal (LC) phase at room temperature (RT). GDCS molecules self‐assemble into supramolecular disks consisting of a pair of molecules in a side‐by‐side disposition assisted by secondary bonding interactions of the lateral polar cyano group, which, in turn, constitute the hexagonal columnar LC st

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, and electronic structure calculations, the spontaneous and stimulated emission properties are quantified and rationalized from a perspective of well-established

Abstract Volatile solid additives are an effective strategy for optimizing morphology and improving the power conversion efficiencies (PCEs) of organic solar cells (OSCs). Much research has been conducted to understand the role of solid additives in active layer morphology. However, it is crucial to delve deeper and understand how solid additives affect the entire morphology evolution process, from the solution state to the film state and the thermal annealing stage, which remains unclear. Herei

Abstract Highly volatile solid additives have attracted much attention recently because they enhance molecular packing order and possibly solve the problems of poor reproducibility and instability of polymer solar cells (PSCs) with solvent additives. The shortcoming is that existing solid additives require thermal annealing (TA) to remove them from the active layer, leading to an increase in the complexity of the device fabrication process and morphology rearrangement problems. This study introd

The minimal structure of a wholly π-conjugated aromatic organogelator was explored in this work to show that distyrylbenzene with simple β-cyano substitution (β-DCS) is highly efficient for gelation which is attributed to the cooperative interplay of π–π stacking and secondary bonding interactions of dipolar cyano groups.

Ternary organic solar cells (OSCs) have attracted much attention due to them being high‐performance solar cells. Ternary OSCs represent an efficient strategy to gain both the benefits of enhanced photon energy harvesting using multiple organic materials, similar to that in tandem OSCs, and the easy fabrication of simple single‐junction device structures. The properties of ternary OSCs are closely related to their complex energy/charge dynamics mechanisms and unique thermodynamic features of blen

(2Z,2′Z)-2,2′-(1,4-phenylene)bis(3-(3,4,5-tris(dodecyloxy)phenyl)acrylonitrile) (GDCS) molecules self-assemble into supramolecular disks consisting of a pair of molecules in a side-by-side dis-position assisted by secondary bonding interactions of the lateral polar cyano group, which, in turn, constitute the hexagonal columnar LC structure. As demonstrated on page 61 by Dongho Kim, Soo Young Park, and co-workers, uniaxially aligned liquid crystal (LC) and crystalline GDCS microwires with enhance

Three isomeric BzY-series NFAs are developed by introducing inner benzyl side chains. Among the BzY-series NFA-based OSCs processed with non-chlorinated xylene solvents, PM6 : m-BzY exhibits PCE over 16% without an additive and thermal annealing process.

Three nonfullerene acceptors with different inner chain lengths were studied on blade-coated organic solar cells to manipulate the Marangoni flow. Consequently, L8- i -EB, with the shortest inner chain, exhibits homogeneous morphology and performance.

Alongside high power conversion efficiencies (PCEs), device stability, especially thermal issues, is another key factor for the successful commercialization of nonfullerene acceptor (NFA)-based organic solar cells (OSCs). Considering the significant effects of the side-chain engineering of NFAs on molecular packing and/or locking strongly associated with the thermal stability of OSCs, herein, we present two new isomeric NFAs with 4-fluoro- and 2-fluoro-substituted hexylphenyl two-dimensional (2D

Both organic solar cells (OSCs) and organic thermoelectrics (OTEs) are promising energy-harvesting technologies for future renewable and sustainable energy sources. Among various material systems, organic conjugated polymers are an emerging material class for the active layers of both OSCs and OTEs. However, organic conjugated polymers showing both OSC and OTE properties are rarely reported because of the different requirements toward the OSCs and OTEs. In this study, the first simultaneous inve

Pendant groups in acrylic adhesive polymers (Ads) have a profound influence on adhesive and cohesive properties and additionally on encapsulant application. However, a systematic investigation to assess the impact of the pendant groups' length and bulkiness is rare, and there is not even a single report on applying Ads as interfacial adhesion promotors and encapsulation materials simultaneously. Herein, we have developed a series of multifunctional methacrylic polymers, namely, R-<i>co</i>-Ads,

By incorporating a dithieno[3,2-<i>f</i>:2',3'-<i>h</i>]quinoxaline unit into a PM6 polymer backbone, we developed a novel terpolymer family, demonstrating composition-dependent optical, electrochemical, and morphological characteristics. Organic solar cells based on the combination of a terpolymer and ternary strategy achieved a high power conversion efficiency of 17.60%, demonstrating the validity of our combination strategy.

A novel molecular design approach was developed for a thermally activated delayed fluorescence emitter based on the 2,3-bis(4-cyanophenyl)quinoxaline-6,7-dicarbonitrile acceptor.