Publications by authors named "Wooje Han"

Article Synopsis
  • Researchers developed high-efficiency quantum dot light-emitting diodes (QLEDs) using lithium-doped titanium dioxide nanoparticles (TiO NPs) as an electron transport layer (ETL) to enhance device performance.
  • The addition of lithium improves charge balance by raising the conduction band minimum, which helps manage electron injection effectively.
  • A green QLED with 5% Li-doped TiO NPs achieved record performance metrics, including maximum luminance of 169,790 cd/m², an external quantum efficiency of 10.27%, and a current efficiency of 40.97 cd/A, demonstrating the potential of Li-doped TiO NPs for future QLEDs.
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Mesoporous Al-doped ZnO thin films incorporated with gold nanoparticles (Au NPs) were synthesized using a sol-gel and evaporation-induced self-assembly process. In this study, the complementary effects of Au NP incorporation and Al doping on the thermoelectric properties of mesoporous ZnO thin films were analysed. The incorporated Au NPs induced an increase in electrical conductivity but a detriment in the pore arrangement of the mesoporous ZnO thin film, which was accompanied by a decrease in porosity.

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Zinc oxide (ZnO) nanocrystals (NCs) were synthesized using a modified sol-gel method. Ultraviolet (UV) treatment was performed under various atmospheres on the highly stacked ZnO NCs. The prepared NCs were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, photoluminescence spectroscopy, and atomic force microscopy to investigate their structural, electrical, and electrochemical properties.

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Fluoropolymer nanocomposites of poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) were prepared using fluorinated barium strontium titanate (BaSrTiO, BSTO) nanoparticles (NPs) by low-temperature synthesis using a modified liquid-solid solution process. The exact stoichiometry of as-synthesized BSTO NPs was confirmed by X-ray diffraction analysis along with lattice parameter calculations. The synthesized BSTO NPs were fluorinated using 2,2,2-trifluoroacetic acid as a fluorous ligand.

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Nanoscale ZnO is one of the best choices for ultraviolet (UV) protection, not only because of its antimicrobial properties but also due to its potential application for UV preservation. However, the behavior of nanostructured thin ZnO films and long-term effects of UV-radiation exposure have not been studied yet. In this study, we investigated the UV-protection ability of sol gel-derived thin ZnO films after different exposure times.

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Cross-point array (CPA) structure memories using a memristor are attracting a great deal of attention due to their high density integration with a 4F2 cell. However, a common significant drawback of the CPA configuration is crosstalk between cells. To date, the CPA structure using a redox-based memristor has restrictions to minimize the operating current level due to their resistive switching mechanism.

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