Publications by authors named "Do Hui Kim"

Non-fullerene acceptors (NFAs) significantly enhance photovoltaic performance in organic solar cells (OSCs) using halogenated solvents and additives. However, these solvents are environmentally detrimental and unsuitable for industrial-scale production, and the issue of OSCs' poor long-term stability persists. This report introduces eight asymmetric NFAs (IPCnF-BBO-IC2F, IPCnF-BBO-IC2Cl, IPCnCl-BBO-IC2F, and IPCnCl-BBO-IC2Cl, where n = 1 and 2).

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In conventional fullerene-based organic photovoltaics (OPVs), in which the excited electrons from the donor are transferred to the acceptor, the electron charge transfer state () that electrons pass through has a great influence on the device's performance. In a bulk-heterojunction (BHJ) system based on a low bandgap non-fullerene acceptor (NFA), however, a hole charge transfer state () from the acceptor to the donor has a greater influence on the device's performance. The accurate determination of is essential for achieving further enhancement in the performance of non-fullerene organic solar cells.

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High thermal stability is crucial for the commercialization of organic solar cells (OSCs). The thermal stability of OSCs has been improved using the tailoring blend morphology of bulk heterojunctions (BHJs). Herein, we demonstrated thermally stable OSCs in a ternary blended system containing low-crystalline semiconducting polymers ( and PTB7-Th) and a non-fullerene acceptor (Y6).

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The concurrent enhancement of short-circuit current ( ) and open-circuit voltage ( ) is a key problem in the preparation of efficient organic solar cells (OSCs). In this paper, we report efficient and stable OSCs based on an asymmetric non-fullerene acceptor (NFA) IPC-BEH-IC2F. The NFA consists of a weak electron-donor core dithienothiophen[3,2-]-pyrrolobenzothiadiazole (BEH) and two kinds of strong electron-acceptor (A) units [9-indeno[1,2-]pyrazine-2,3-dicarbonitrile (IPC) with a tricyclic fused system and 2-(5,6-difluoro-3-oxo-2,3-dihydro-1-inden-1-ylidene)malononitrile (IC2F)].

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A series of anionic conjugated polyelectrolytes (CPEs) is synthesized based on poly(fluorene-co-phenylene) by varying the side-chain ionic density from two to six per repeat units (MPS2-TMA, MPS4-TMA, and MPS6-TMA). The effect of MPS2, 4, 6-TMA as interlayers on top of a hole-extraction layer of poly(bis(4-phenyl)-2,4,6-trimethylphenylamine (PTAA) is investigated in inverted perovskite solar cells (PeSCs). Owing to the improved wettability of perovskites on hydrophobic PTAA with the CPEs, the PeSCs with CPE interlayers demonstrate a significantly enhanced device performance, with negligible device-to-device dependence relative to the reference PeSC without CPEs.

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The enhancement of interfacial charge collection efficiency using buffer layers is a cost-effective way to improve the performance of organic photovoltaic devices (OPVs) because they are often universally applicable regardless of the active materials. However, the availability of high-performance buffer materials, which are solution-processable at low temperature, are limited and they often require burdensome additional surface modifications. Herein, high-performance ZnO based electron transporting layers (ETLs) for OPVs are developed with a novel -ray-assisted solution process.

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We demonstrated a water-resistant PEDOT:PSS HTL by incorporating a photo-crosslinking agent into a PEDOT:PSS film. A crosslinking system was successfully formed inside the PEDOT:PSS film by simple and fast photo-polymerization of PCDSA monomers. Combination of the crosslinking system and MeOH surface treatment simultaneously improved the device efficiency and stability of both perovskite and polymer solar cells.

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Over the last decades, the spin-coating (SC) technique has been widely used to prepare thin films of various materials in the liquid phase on arbitrary substrates. The technique simply relies on the centrifugal force to spread a coating solution radially outward over the substrate. This mechanism works fairly well for solutions with low surface tension to form thin films of reasonable junctions on smooth substrates.

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