Highly Sensitive and Selective Acetylene CuO/ZnO Heterostructure Sensors through Electrospinning at Lean O Concentration for Transformer Diagnosis.

Acetylene (CH) is a gas that can cause explosions in transformers even at low concentrations. Gas chromatography (GC) or photoacoustic spectroscopy (PAS) have been used to detect CH during dissolved gas analysis (DGA), but they are not suitable for monitoring numerous transformers at substations. Even though metal oxide semiconductor (MOS) based CH sensors have drawn much attention as a potential solution, existing MOS-based CH sensors have low sensitivity toward CH in the transformer environment (<2% O concentrations).

Surface Reconstruction of a Perovskite Film by an Organic Salt for High-Performance Solar Cells with Improved Stability.

Organic-inorganic lead halide perovskites have undergone tremendous development due to their excellent optoelectrical properties, achieving exceptional photovoltaic performance up to over 25%. The interface engineering method has a significant role in further improving the perovskite solar cell performance to its limit. Herein, we fabricated a modified GAMAPbI perovskite film using the organic amine small molecule 3-(aminomethyl)pyridine (3AP), which increased the grain sizes and crystallinity through the modulated melting process as well as reacted with the surface component, especially the defect site of the PbI octahedral layer, resulting in a high-quality perovskite film.

Diammonium spacer-induced stable zigzag type 2D Dion-Jacobson lead/tin-based perovskite solar cells.

Hybrid halide two dimensional (2D) perovskites have attracted considerable attention because they exhibit an improvement in perovskite solar cells compared with their 3D analogs. However, their bulky organic space group, leading to higher bandgaps and exciton binding energy, limits the charge transport in solar cells. Herein, the 3-(aminomethyl)pyridinium (3API, CHNI) dication is incorporated into FA(PbSn)I to develop zigzag type 2D Dion-Jacobson-phase perovskites, which have low band gaps in the range of 1.

Long-lived spin-triplet excitons in manganese complexes for room-temperature phosphorescence.

Low-dimensional metal halide perovskites have become emerging candidates for applications in light emitting diodes due to the quantum confinement effect by tuning their composition and structure. However, they suffer from longstanding issues of environmental stability and lead toxicity. Herein, we report phosphorescent manganese halides, (TEM)MnBr (TEM = HN(CHCH), triethylammonium) and (IM)[MnBr][MnBr] (IM = CHN, imidazolium) with a photoluminescence quantum yield (PLQY) of 50% and 7%, respectively.

Formation of cubic perovskite alloy containing the ammonium cation of 2D perovskite for high performance solar cells with improved stability.

The perovskite solar cells have demonstrated to be strong competitors for conventional silicon solar cells due to their remarkable power conversion efficiency. However, their structural instability is the biggest obstacle to commercialization. To address these issues, we prepared (CHNH) (HC(NH)) PbI (CHNH = MA, HC(NH) = FA) perovskite alloys that contain ethylammonium (EA, CHCHNH ) and benzylammonium (BA, CHCHNH ) cations with no new additional two-dimensional (2D) perovskite phases.

The red light emission in 2D (CSHCHNH)SnI and (COHCHNH)SnI perovskites.

Two-dimensional (2D) perovskites have a large exciton binding energy due to the structure of the quantum confinement, which produces a faster radiative recombination, and so are promising potential materials for light-emitting diodes. However, most of the highly efficient hybrid halide perovskites are based on the toxic Pb-based materials, so the replacement of Pb with less toxic and suitable substitute elements has been investigated for environmental efficient materials. Herein, we report the Sn-based 2D perovskites, which include (TPM)2SnI4 (TPM = C4SH3CH2NH3) and (TFF)2SnI4 (TFF = C4OH7CH2NH3), as red emission materials.

Stacking of Layered Halide Perovskite from Incorporating a Diammonium Cation into Three-Dimensional Perovskites.

Quasi two-dimensional (2D) layered perovskites have been emerging as promising candidates for photovoltaic cells because they exhibit intrinsic stability and a higher tunability of optical properties compared to three-dimensional (3D) perovskites. However, since most 2D perovskites have bulkier groups as an organic space group, they will inevitably have a van der Waals gap between the inorganic layers and their crystal growth directions orient in a lateral direction. It also interrupts carrier transport across the conducting inorganic layer in the solar cell.

Broadband white-light emission from supramolecular piperazinium-based lead halide perovskites linked by hydrogen bonds.

We demonstrate white-light emission using lead halide perovskites: (pip)2PbBr6 (pip = piperazine), (pip)2Pb4Cl12, (1mpz)2PbBr6 (1mpz = 1-methylpiperazine), and (2,5-dmpz)0.5PbBr3·2((CH3)2SO) (2,5-dmpz = trans-2,5-dimethylpiperazine, abbreviated as (2,5-dmpz)0.5PbBr3), in which the inorganic frameworks were connected by piperazinium dications through hydrogen bonds, forming a three-dimensional supramolecular network.

White-Light Emission from the Structural Distortion Induced by Control of Halide Composition of Two-Dimensional Perovskites ((CHCHNH)PbBrCl ).

Two-dimensional (2D) perovskites, which have a 2D orientation of the inorganic framework that determines largely the electronic characteristics and an organic cation in the interlayer that leads to a quantum well structure, have attracted a great deal of attention due to their superior stable optoelectronic properties. Especially, some of the greatest interest in 2D perovskites is their application in broad-band white-light emission for solid state lighting. We prepared (BZA)PbBrCl (BZA= benzylammonium and x = 0, 1.

Carbon-coated ZnO mat passivation by atomic-layer-deposited HfO as an anode material for lithium-ion batteries.

ZnO has had little consideration as an anode material in lithium-ion batteries compared with other transition-metal oxides due to its inherent poor electrical conductivity and large volume expansion upon cycling and pulverization of ZnO-based electrodes. A logical design and facile synthesis of ZnO with well-controlled particle sizes and a specific morphology is essential to improving the performance of ZnO in lithium-ion batteries. In this paper, a simple approach is reported that uses a cation surfactant and a chelating agent to synthesize three-dimensional hierarchical nanostructured carbon-coated ZnO mats, in which the ZnO mats are composed of stacked individual ZnO nanowires and form well-defined nanoporous structures with high surface areas.

Comparative experiments of graphene covalently and physically binding CdSe quantum dots to enhance the electron transport in flexible photovoltaic devices.

In this research, we prepared composite films via covalent coupling of CdSe quantum dots (QDs) to graphene through the direct binding of aryl radicals to the graphene surface. To compare the carrier transport with the CdSe aryl binding graphene film, we prepared CdSe pyridine capping graphene films through the pi-pi interactions of noncovalent bonds between the graphene and pyridine molecules. The photovoltaic devices were fabricated from the two hybrid films using the electrophoretic deposition method on flexible substrates.

Fabrication of Ag nanoparticles embedded in TiO2 nanotubes: using electrospun nanofibers for controlling plasmonic effects.

Composites of electrospun poly(ethylene oxide) (PEO) fibers and silver nanoparticles (Ag NPs) were used as a soft template for coating with TiO2 by atomic layer deposition (ALD). Whereas the as-deposited TiO2 layers on PEO fibers and Ag NPs were completely amorphous, the TiO2 layers were transformed into polycrystalline TiO2 nanotubes (NTs) with embedded Ag NPs after calcination. Their plasmonic effect can be controlled by varying the thickness of the dielectric Al2 O3 spacer between Ag NPs and dye molecules by means of the ALD process.

TiO2 nanotube fabrication with highly exposed (001) facets for enhanced conversion efficiency of solar cells.

We demonstrate that the use of poly(vinyl pyrrolidone) (PVP) and acetic acid during the synthesis of TiO(2) nanotubes may result in the synthesis of single-crystal-like anatase TiO(2) with a mainly exposed and chemically active (001) facet. An enhancement in the overall conversion efficiency of dye-sensitized solar cells was observed in a photoanode consisting of TiO(2) single-crystal-like anatase exposed (001) facets.

Selective patterning of ZnO nanorods on silicon substrates using nanoimprint lithography.

In this research, nanoimprint lithography (NIL) was used for patterning crystalline zinc oxide (ZnO) nanorods on the silicon substrate. To fabricate nano-patterned ZnO nanorods, patterning of an n-octadecyltrichlorosilane (OTS) self-assembled monolayers (SAMs) on SiO2 substrate was prepared by the polymer mask using NI. The ZnO seed layer was selectively coated only on the hydrophilic SiO2 surface, not on the hydrophobic OTS SAMs surface.

Anomalous bronchial artery originating from the right coronary artery in a patient with angina (2009: 4b).

Bronchial artery origins are subject to a wide range of anatomic variations, of which interventional radiologists should be aware. The authors report a patient with angina in whom an anomalous bronchial artery originated from the sinus node branch of the right coronary artery, causing a coronary steal phenomenon. The patient's symptom was successfully treated by transcatheter embolisation of the anomalous bronchial artery, which seems to be an effective alternative to surgery.

Patterning of conducting polymers using charged self-assembled monolayers.

We introduce a new approach to pattern conducting polymers by combining oppositely charged conducting polymers on charged self-assembled monolayers (SAMs). The polymer resist pattern behaves as a physical barrier, preventing the formation of SAMs. The patterning processes were carried out using commercially available conducting polymers: a negatively charged PEDOT/PSS (poly(3,4-ethylene-dioxythiophene)/poly(4-stylenesulphonic acid)) and a positively charged polypyrrole (PPy).

Surface treatment and characterization of ITO thin films using atmospheric pressure plasma for organic light emitting diodes.

Ar atmospheric pressure plasma (APP) was used to treat indium-tin-oxide (ITO). The plasma conditions were varied to treat the ITO surface, e.g.