Ki-Jung Yong

A simple method of synthesizing nanomaterials and the ability to control the size and position of them are crucial for fabricating nanodevices. In this work, we developed a novel ammonia aqueous solution method for growing well-aligned ZnO nanorod arrays on a silicon substrate. For ZnO nanorod growth, a thin zinc metal seed layer was deposited on a silicon substrate by thermal evaporation. Uniform ZnO nanorods were grown on the zinc-coated silicon substrate in aqueous solution containing zinc ni

ZnO/CdS core/shell nanowire heterostructure arrays are fabricated by a two-step chemical solution method for use in semiconductor-sensitized photoelectrochemical cells (PECs). The successive ion layer adsorption and reaction (SILAR) shows a remarkable controllability of CdS shell thickness, which affects visible-light absorption properties and PEC performances of the heterostructures. The cell has a high short-circuit photocurrent density of 7.23 mA/cm2 with a power conversion efficiency of 3.53

In this study, a novel and facile passivation process for a perovskite solar cell is reported. Poor stability in ambient atmosphere, which is the most critical demerit of a perovskite solar cell, is overcome by a simple passivation process using a hydrophobic polymer layer. Teflon, the hydrophobic polymer, is deposited on the top of a perovskite solar cell by a spin-coating method. With the hydrophobic passivation, the perovskite solar cell shows negligible degradation after a 30 day storage in

This work reports the H 2 S gas-sensing properties of ZnO nanorod bundles and an investigation of their gas sensing mechanism. A one-dimensional ZnO nanostructure was synthesized using the hydrothermal method; scanning electron microscopy (SEM); and X-ray diffraction (XRD) spectra confirmed that the structures were crystalline ZnO of hexagonal structure. A furnace-type gas sensing system was used to characterize the nanorod bundles’ sensing properties in air containing dilute H 2 S gas (50 ppm)

In this communication, a novel CdSe/CdS/ZnO nanowire array fabricated by a 3-step solution-based method was used as a photoanode of a quantum dot sensitized solar cell, which generated a maximum power conversion efficiency of 4.15%.

This study reports on the structural properties of CuO/ZnO nanorods and the mechanism by which bundles of these nanorods are able to sense H 2 S gas. The CuO/ZnO nanorods were prepared by deposition of CuO nanostructures on the hydrothermally grown ZnO nanorods using a photochemical method. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to confirm that the heterogeneous nanostructure of the CuO/ZnO nanorods was highly crystalline.

Tungsten oxide (WO 3 ) nanowires were prepared on a tungsten (W) substrate by thermal evaporation of WO 3 powder at elevated temperature in a tube furnace. The morphology, structure, composition, and chemical state of the prepared nanowires were characterized by SEM, EDX, TEM, XRD, Raman spectroscopic, and XPS measurements. The nanowires grown using WO 3 powder were found to have uniform morphology with a high density and a crystalline structure consistent with monoclinic WO 3 . The field-emissi

Abstract A Z‐scheme heterojunction with spatially separated cocatalysts is proposed for overcoming fundamental issues in photocatalytic water splitting, such as inefficient light absorption, charge recombination, and sluggish reaction kinetics. For efficient light absorption and interfacial charge separation, Z‐scheme organic/inorganic heterojunction photocatalysts are synthesized by firmly immobilizing ultrathin g‐C 3 N 4 on the surface of TiO 2 hollow spheres via electrostatic interactions. Ad

We report the photocatalytic activity of flower-like CuO-ZnO heterostructured nanowires (NWs) fabricated on a stainless steel mesh. The mesh provided an extensive surface area and facilitated efficient mass transfer. The composed NWs exhibited excellent photocatalytic activity and showed additional enhanced properties due to multilayered, dual light source effects during the photodecomposition of a non-biodegradable azo dye.

We report a two-step, solution-based synthetic method to fabricate CdS nanoparticles-sensitized ZnO nanowire heterostructure arrays which showed enhanced photocatalytic activities in comparison with bare ZnO nanowire arrays.

A light incident angle selectivity of a memory device is demonstrated. As a model system, the ZnO resistive switching device has been selected. Electrical signal is reversibly switched between memristor and resistor behaviors by modulating the light incident angle on the device. Moreover, a liquid passivation layer is introduced to achieve stable and reversible exchange between the memristor and WORM behaviors.

Abstract On the basis of the many advantages of quantum dots (QDs) including multiple exciton generation, high absorption coefficient, and band‐gap energy controllability, quantum‐dot‐sensitized solar cells (QDSSCs) have been studied for a few decades. However, despite the many advantages, improvement in the power‐conversion efficiencies of QDSSCs has been stagnated for a long time. To suggest a breakthrough in this stagnated QDSSC field, counter electrodes (CEs) have been focused on and are int