Jong‐Lam Lee

Hybrid materials consisting of semiconductors and cocatalysts have been widely used for photoelectrochemical (PEC) conversion of CO₂ gas to value-added chemicals such as formic acid (HCOOH). To date, however, the rational design of catalytic architecture enabling the reduction of <i>real</i> CO₂ gas to chemical has remained a grand challenge. Here, we report a unique photocathode consisting of CuS-decorated GaN nanowires (NWs) integrated on planar silicon (Si) for the conve

Thermally evaporable BCP/Ag/MoO3 is demonstrated as a transparent cathode for flexible OPVs. The optical transmittance of Ag film is enhanced by refractive index-matching layers. BCP/Ag/MoO3 can fulfill the optimum zero-reflection condition, resulting in high transmittance (75.5%) and low sheet resistance (8.6 ohm/sq). BCP/Ag/MoO3 cathodes could be applicable as general transparent cathodes for flexible organic optoelectronic devices.

The change of the Fermi energy level at the interface of Pd/p-type GaN by surface treatment was investigated using positron annihilation spectroscopy, and the results were used to provide interpretation of the electrical properties of the contact. Changes in the positron parameters at the interface in the aqua regia-treated GaN are more pronounced than that in the HCl-treated one. This provides evidence that the surface treatment with aqua regia prior to Pd metal deposition removes surface oxide

Electrochemical reduction of carbon dioxide (CO2) is a promising method toward carbon recycling. Highly selective bimetallic catalysts have been extensively demonstrated, while efforts to understand the compositional and geometrical effects have been limited. Here, we studied the relationship between the catalytic activity of bimetallic Cu–Sn catalysts with their composition and geometry through the fabrication of three-dimensional hierarchical (3D-h) Cu nanostructure and the solution-based coat

The light out-coupling efficiency of OLEDs is enhanced by the use of a refractive index modulation layer (RIML) with MgO nanofacet structure (see figure) that can be formed without an additional lithographic or patterning processes. Increases in luminance and power efficiency of up to 19% and 34.7%, respectively, are demonstrated. Low out-coupling efficiency is one of the main limitations to highly efficient OLEDs, so overcoming it would allow substantial improvements.

In this study, the role of anions in Au complexes was investigated as a dopant for graphene. Au(OH)3, Au2S, AuBr3, and AuCl3 were used as dopants. The average sheet resistance of the graphene decreased from 950 Ω sq−1 to 820, 600, 530, and 300 Ω sq−1 and the work function increased from 4.3 eV to 4.6, 4.8, 5.0 and 4.9 eV with Au(OH)3, Au2S, AuBr3, and AuCl3 dopants, respectively. However, thermal annealing of graphene increased the sheet resistance and decreased the work function. Furthermore, t

The electrochemical CO₂ reduction in aqueous media is a promising method for both the mitigation of climate changes and the generation of value-added fuels. Although many researchers have demonstrated selective and stable catalysts for electrochemical reduction of pure CO₂ gas, the conversion of industrial CO₂ gas has been limited. Here, we fabricated the copper sulfide catalysts (CuS_<i>x</i>), which were spontaneously formed by dipping a Cu foil into

We investigated the relationship between grain boundary (GB) oxidation of Cu-Ag thin-film catalysts and selectivity of the (photo)electrochemical CO₂ reduction reaction (CO₂ RR). The change in the thickness of the Cu thin film accompanies the variation of GB density, and the Ag layer (3 nm) has an island-like morphology on the Cu thin film. Therefore, oxygen from ambient air penetrates into the Cu thin film through the GB of Cu and binds with it because the uncoordinated Cu