이찬우 교수

We describe a novel and versatile approach for preparing resistive switching memory devices based on binary transition metal oxides (TMOs). Titanium isopropoxide (TIPP) was spin-coated onto platinum (Pt)-coated silicon substrates using a sol-gel process. The sol-gel-derived layer was converted into a TiO2 film by thermal annealing. A top electrode (Ag electrode) was then coated onto the TiO2 films to complete device fabrication. When an external bias was applied to the devices, a switching pheno

A perovskite La_0.2Sr_0.8Co_0.8Fe_0.2O_3−δ catalyst exhibited remarkably high activities for the ORR and OER as a novel bifunctional oxygen electrode for reversible SOCs.

Abstract Protonic ceramic electrochemical cells (PCECs) hold great promise as an energy conversion and storage technology at lower temperatures (400–650 °C). However, the sluggish reaction kinetics at the oxygen electrode hinder the electrochemical activity of PCECs. Herein, a series of bifunctional oxygen electrodes based on bimetal‐doped BaCoO 3‐𝛿 (BCO) are reported. Doping hampers hexagonal perovskite formation and transforms BCO into cubic perovskite, improving water uptake and hydration abi

It is demonstrated that notable resistive switching memory properties depending on voltage polarity (i.e. bipolar switching properties) can be obtained from the layer-by-layer (LbL) assembled multilayers based on transition metal oxides and metal nanoparticles. Cationic poly(allylamine hydrochloride) and anionic titania precursor layers were deposited alternately onto Pt-coated Si substrates using an electrostatic LbL assembly process. Anionic Pt nanoparticles (Pt(NP)) with about 5.8 nm diameter

Titanium dioxide (TiO₂) with exposed (001) facets (TiO₂(001)) has attractive photocatalytic properties. However, the high recombination rate of the photo-excited charge carriers on this surface often limits its application. Here, we report that a few-layered 1T-MoS₂ coating on TiO₂(001) nanosheets (abbreviated as MST) can be a promising candidate that overcomes some of the challenges of TiO₂(001). Computational and experimental results demon

Co₃O₄ nanograins-interconnected secondary particle (Co₃O₄ NISP) is proposed as lithium-ion battery anode material that can offer high volumetric capacity by less formation of insulating CoO during lithiation process.

We describe a novel and versatile approach for preparing resistive switching memory devices based on transition metal oxides. A titania precursor and poly(allyamine hydrochloride) (PAH) layers were deposited alternately onto platinum (Pt)-coated silicon substrates using electrostatic interactions. The multilayers were then converted to TiO2 nanocomposite (TiO2 NC) films after thermal annealing. A top electrode was coated on the TiO2 NC films to complete device fabrication. When an external bias

The modular biosynthetic pathway of ribosomally synthesized and post-translationally modified peptides (RiPPs) enhances their engineering potential for exploring new structures and biological functions. The ω-ester-containing peptides (OEPs), a subfamily of RiPPs, have distinct side-to-side ester or amide linkages and frequently present more than one macrocyclic domain in a "beads-on-a-string" structure. In an effort to improve the engineering potential of RiPPs, we present here the idea that th

Density functional theory is used to determine the stabilization mechanisms of LaFeO 3 (010) surfaces over a range of surface oxygen stoichiometries. For the stoichiometric LaO surface, and for reduced surface terminations, an electron‐rich surface is needed for stabilization. By contrast, in the case of the stoichiometric FeO 2 surface and oxidized surface terminations with low‐coordinated oxygen atoms, a hole‐rich surface is needed for stabilization. The calculations further predict that low c

Abstract Fast oxygen-ion conductors for use as electrolyte materials have been sought for energy conversion and storage. Bi 2 O 3 -based ionic conductors that exhibit the highest known oxygen-ion conductivities have received attention for use in next-generation solid electrolytes. However, at intermediate temperatures below ~600 °C, their conductivities degrade rapidly owing to a cubic-to-rhombohedral phase transformation. Here, we demonstrate that physical manipulation of the grain structure ca

We demonstrate a Cu(I) and Cu(II) codoped nickel(II) oxide (NiOx) hole injection layer (HIL) for solution-processed hybrid organic-inorganic light-emitting diodes (HyLEDs). Codoped NiOx films show no degradation on optical properties in the visible range (400–700 nm) but have enhanced electrical properties compared to those of conventional Cu(II)-only doped NiOx film. Codoped NiOx film shows an over four times increased vertical current in comparison with that of NiOx in conductive atomic force

Reduced graphene oxide (rGO)-based micro-supercapacitors (MSCs) have emerged as a new type of micro-energy storage device. However, the low volumetric energy density of rGO hampers the application of MSCs in miniaturized energy storage devices. Hybridization of pseudocapacitive materials with rGO is a potential approach to increase the energy density of MSCs. Herein, a densely packed hybrid film of birnessite-type manganese oxide (K-MnOx) supported by rGO is developed, and hybrid-film-based MSCs