서홍 교수

Abstract Ultra‐deep‐blue aggregation‐induced delayed fluorescence (AIDF) emitters (TB‐tCz and TB‐tPCz) bearing organoboron‐based cores as acceptors and 3,6‐substituted carbazoles as donors are presented. The thermally activated delayed fluorescence (TADF) properties of the two emitters are confirmed by theoretical calculations and time‐resolved photoluminescence experiments. TB‐tCz and TB‐tPCz exhibit fast reverse intersystem crossing rate constants owing to efficient spin–orbit coupling between

A highly crystalline conjugated donor (D)-acceptor (A) block copolymer (PBDT2T-<i>b</i>-N2200) that has good solubility in nonhalogenated solvents is successfully synthesized. PBDT2T-<i>b</i>-N2200 shows a broad complementary absorption behavior owing to a wide-band gap donor (PBDT2T) present as a D-block and a narrow-band gap acceptor (N2200) present as an A-block. Polymer solar cells (PSCs) with conjugated block copolymer (CBCP) are fabricated using a toluene solution and PSC created with an a

A single component polymer solar cell with a CDABP film annealed at 180 °C showed a maximum power conversion efficiency of 5.28%, which is much higher than that (2.62%) of the device with the as-cast film.

Conjugated random terpolymers, <b>PJ-25</b>, <b>PJ-50</b>, and <b>PJ-75</b> were successfully synthesized from three different monomers. Fluorine-substituted benzotriazole (2F-BTA) was incorporated into 4,8-bis(4-chlorothiophen-2-yl)benzo[1,2-<i>b</i>:4,5-<i>b</i>']dithiophene (BDT-T-Cl) and a 1,3-bis(4-(2-ethylhexyl)thiophen-2-yl)-5,7-bis(2-alkyl)benzo[1,2-<i>c</i>:4,5-<i>c</i>']dithiophene-4,8-dione (BDD)-based alternating copolymer PM7 as a third monomeric unit. The solubility of the random t

Fullerene-free polymer solar cells with the as-cast blend film of <bold>IDT-3MT</bold> and PBDB-T exhibited a high PCE of 8.40%.

In this study, we synthesized three novel aromatic imide-based conjugated donor(D)-σ-acceptor (A) dyad-based polymers showing different photophysical properties. These D-σ-A dyad-based polymers (e.g., BDTBT-NI, BDTBT-NDI, and BDTBT-PDI) consist of the same conjugated donor main chains (benzodithiophene-bithiophene (BDTBT)) and side chains bearing different imide acceptors (naphthalimide (NI), naphthalene diimide (NDI), or perylenediimide (PDI)). The photophysical and electrochemical characterist

In solution-processed organic light-emitting diodes (OLEDs), achieving high color purity and efficiency is as important as that in vacuum processes. Emitters suitable for solution processing must have excellent solubility in organic solvents, high molecular weight, and compatibility with the host materials. In this study, we synthesized a deep-blue emitter that satisfies the above conditions by introducing a 1,4-bis(indolo[3,2,1-<i>jk</i>]carbazol-2-yl)benzene-based planar emitting core (DICz) s

In this study, two novel multiple resonance (MR) emitters, DtCzBN and Cy-DtCzBN, were designed based on the well-known BCzBN structure and synthesized for narrowband solution-processed organic light-emitting diodes (OLEDs). Cy-DtCzBN possesses a dimeric V-shaped structure formed by coupling two individual DtCzBN units via a nonconjugated cyclohexane linker. When compared with DtCzBN, Cy-DtCzBN, as a medium-sized molecule, was found to maintain the optical and photophysical properties of the corr

The recent breakthrough in power conversion efficiencies (PCEs) of polymer solar cells (PSCs) that contain an active layer of a ternary system has achieved values of 18-19%; this has sparked interest for further research. However, this system has difficulties in optimizing the composition and controlling the interaction between the three active materials. In this study, we investigated the use of a donor₁ (D₁)-donor₂ (D₂) conjugated block copolymer (CB

The photophysical properties of donor (<b>D</b>)-acceptor (<b>A</b>) polymers were studied by designing two types of polymers, <b>(D-σ-A)</b> _<b>n</b> and <b>(D-π-A)</b> _<b>n</b> , with non-conjugated alkyl (<i>sp</i> ³) and π-conjugated (<i>sp</i> ²) linkers using π-extended donor and acceptor monomers that exhibit planar A-D-A structures. The non-conjugated alkyl linker provides structural flexibility to the <b>(D-σ-A)</b> _<b>n</b> polymer