Effect of pH on Anodic Formation of Nanoporous Gold Films in Chloride Solutions: Optimization of Anodization for Ultrahigh Porous Structures

Nanoporous gold (NPG) structures have useful applications based on their unique physical and chemical properties; therefore, the development of NPG preparation methods is the subject of extensive research. Recently, the anodization of Au surfaces was suggested as an efficient method for preparing porous Au structures. In this work, the mechanistic aspects of the anodization of Au in Cl^–-containing solutions for the preparation of NPG layers were investigated. The effects of the experimental parameters of the anodization reaction on the porosity of the NPG layers in terms of the roughness factor (<i>R</i>_f) were examined. The anodic formation of NPG was more effective in buffered solutions than in unbuffered electrolytes. The <i>R</i>_f of the NPG layer was sensitive to the electrolyte pH; this was ascribed to the efficient formation of protecting layers of gold oxide on the newly formed NPG structures. In buffer solutions at pH 8, ultrahigh porous NPG layers with <i>R</i>_f values of 1300 were obtained within 15 min. The ultrahigh porous NPG layers were used for the electrochemical detection of glucose; a high sensitivity of 135 μA mM^–1 cm^–2 was achieved in the presence of 0.1 M Cl^–. This straightforward and time-saving preparation of NPG surfaces will provide new opportunities for applications of NPG structures

Unraveling the Charge Extraction Mechanism of Perovskite Solar Cells Fabricated with Two-Step Spin Coating: Interfacial Energetics between Methylammonium Lead Iodide and C₆₀

In organolead halide perovskite solar cells (PSCs), interfacial properties between the perovskite and charge transport layers are the critical factors governing charge extraction efficiency. In this study, the effect of interfacial energetics between two-step spin-coated methylammonium lead iodide (MAPbI₃) with different methylammonium iodide (MAI) concentrations and C₆₀ on the charge extraction efficiency is investigated. The electronic structures of perovskite films are significantly varied by the MAI concentrations due to the changes in the residual precursor and MA⁺ defect content. As compared to the optimum PSCs with 25 mg mL^–1 MAI, PSCs with other MAI concentrations show significantly lower power conversion efficiencies and severe hysteresis. The energy level alignment at the C₆₀/MAPbI₃ interface determined by ultraviolet and inverse photoelectron spectroscopy measurements reveals the origin of distinct differences in device performances. The conduction band offset at the C₆₀/MAPbI₃ interface plays a crucial role in efficient charge extraction in PSCs

DataSheet_1_Detection and evaluation of signals for immune-related adverse events: a nationwide, population-based study.docx

BackgroundImmune checkpoint inhibitors (ICIs) are one of the main pillars of cancer therapy. Since other studies such as clinical trial and retrospective study have limitations for detecting the immune-related adverse events (irAEs) characterized by unpredictable onset, nonspecific symptoms and wide clinical spectrum, we aimed to identify the incidence of irAEs and to detect and evaluate the signals using real-world data.MethodsCancer patients treated with anticancer medications were analyzed using the nationwide health insurance claims database of South Korea from 2017 to 2019, and Clinical Data Warehouse (CDW) database of Asan Medical Center (AMC), a tertiary referral hospital, from 2012 to 2019. AEs of ICI users were compared with those of non-ICI anticancer medication users. PD-1 inhibitors (nivolumab and pembrolizumab) and PD-L1 inhibitors (atezolizumab) were evaluated. We defined an AE as a newly added diagnosis after the ICI prescription using an ICD-10 diagnostic code. A signal was defined as an AE that was detected by any one of the four indices of data mining: hazard ratio (HR), proportional claims ratio (PCR), claims odds ratio (COR), or information component (IC). All detected signals were reviewed and classified into well-known or potential irAEs. Signal verification was performed for targeted AEs using CDW of AMC using diagnostic codes and text mining.ResultsWe identified 118 significant signals related to ICI use. We detected 31 well-known irAEs, most of which were endocrine diseases and skin diseases. We also detected 33 potential irAEs related to disorders in the nervous system, eye, circulatory system, digestive system, skin and subcutaneous tissues, and bones. Especially, portal vein thrombosis and bone disorders such as osteoporosis with pathological fracture and fracture of shoulder, upper arm, femur, and lower leg showed high HR in ICI users than in non-ICI users. The signals from hospital database were verified using diagnostic codes and text mining.ConclusionThis real-world data analysis demonstrated an efficient approach for signal detection and evaluation of ICI use. An effective real-world pharmacovigilance system of the nationwide claims database and the EMR could complement each other in detecting significant AE signals.</p

Band-Tail Transport of CuSCN: Origin of Hole Extraction Enhancement in Organic Photovoltaics

Copper thiocyanate (CuSCN) is known as a promising hole transport layer in organic photovoltaics (OPVs) due to its good hole conduction and exciton blocking abilities with high transparency. Despite its successful device applications, the origin of its hole extraction enhancement in OPVs has not yet been understood. Here, we investigated the electronic structure of CuSCN and the energy level alignment at the poly­(3-hexylthiophene-2,5-diyl) (P3HT)/CuSCN/ITO interfaces using ultraviolet photoelectron spectroscopy. The band-tail states of CuSCN close to the Fermi level (<i>E</i>_F) were observed at 0.25 eV below the <i>E</i>_F, leading to good hole transport. The CuSCN interlayer significantly reduces the hole transport barrier between ITO and P3HT due to its high work function and band-tail states. The barrier reduction leads to enhanced current density–voltage characteristics of hole-dominated devices. These results provide the origin of hole-extraction enhancement by CuSCN and insights for further application

Surface-Modified Carbon Nanotubes with Ultrathin Co₃O₄ Layer for Enhanced Oxygen Evolution Reaction

Alkaline water electrolysis is a vital technology for sustainable and efficient hydrogen production. However, the oxygen evolution reaction (OER) at the anode suffers from sluggish kinetics, requiring overpotential. Precious metal-based electrocatalysts are commonly used but face limitations in cost and availability. Carbon nanostructures, such as carbon nanotubes (CNTs), offer promising alternatives due to their abundant active sites and efficient charge-transfer properties. Surface modification of CNTs through techniques such as pulsed laser ablation in liquid media (PLAL) can enhance their catalytic performance. In this study, we investigate the role of surface-modified carbon (SMC) as a support to increase the active sites of transition metal-based electrocatalysts and its impact on electrocatalytic performance for the OER. We focus on Co3O4@SMC heterostructures, where an ultrathin layer of Co3O4 is deposited onto SMCs using a combination of PLAL and atomic layer deposition. A comparative analysis with aggregated Co3O4 and Co3O4@pristine CNTs reveals the superior OER performance of Co3O4@SMC. The optimized Co3O4@SMC exhibits a 25.6% reduction in overpotential, a lower Tafel slope, and a significantly higher turnover frequency (TOF) in alkaline water splitting. The experimental results, combined with density functional theory (DFT) calculations, indicate that these improvements can be attributed to the high electrocatalytic activity of Co3O4 as active sites achieved through the homogeneous distribution on SMCs. The experimental methodology, morphology, composition, and their correlation with activity and stability of Co3O4@SMC for the OER in alkaline media are discussed in detail. This study contributes to the understanding of SMC-based heterostructures and their potential for enhancing electrocatalytic performance in alkaline water electrolysis

Vertical and In-Plane Current Devices Using NbS₂/n-MoS₂ van der Waals Schottky Junction and Graphene Contact

A van der Waals (vdW) Schottky junction between two-dimensional (2D) transition metal dichalcogenides (TMDs) is introduced here for both vertical and in-plane current devices: Schottky diodes and metal semiconductor field-effect transistors (MESFETs). The Schottky barrier between conducting NbS₂ and semiconducting n-MoS₂ appeared to be as large as ∼0.5 eV due to their work-function difference. While the Schottky diode shows an ideality factor of 1.8–4.0 with an on-to-off current ratio of 10³−10⁵, Schottky-effect MESFET displays little gate hysteresis and an ideal subthreshold swing of 60–80 mV/dec due to low-density traps at the vdW interface. All MESFETs operate with a low threshold gate voltage of −0.5 ∼ −1 V, exhibiting easy saturation. It was also found that the device mobility is significantly dependent on the condition of source/drain (S/D) contact for n-channel MoS₂. The highest room temperature mobility in MESFET reaches to approximately more than 800 cm²/V s with graphene S/D contact. The NbS₂/n-MoS₂ MESFET with graphene was successfully integrated into an organic piezoelectric touch sensor circuit with green OLED indicator, exploiting its predictable small threshold voltage, while NbS₂/n-MoS₂ Schottky diodes with graphene were applied to extract doping concentrations in MoS₂ channel

Vertical and In-Plane Current Devices Using NbS₂/n-MoS₂ van der Waals Schottky Junction and Graphene Contact

A van der Waals (vdW) Schottky junction between two-dimensional (2D) transition metal dichalcogenides (TMDs) is introduced here for both vertical and in-plane current devices: Schottky diodes and metal semiconductor field-effect transistors (MESFETs). The Schottky barrier between conducting NbS₂ and semiconducting n-MoS₂ appeared to be as large as ∼0.5 eV due to their work-function difference. While the Schottky diode shows an ideality factor of 1.8–4.0 with an on-to-off current ratio of 10³−10⁵, Schottky-effect MESFET displays little gate hysteresis and an ideal subthreshold swing of 60–80 mV/dec due to low-density traps at the vdW interface. All MESFETs operate with a low threshold gate voltage of −0.5 ∼ −1 V, exhibiting easy saturation. It was also found that the device mobility is significantly dependent on the condition of source/drain (S/D) contact for n-channel MoS₂. The highest room temperature mobility in MESFET reaches to approximately more than 800 cm²/V s with graphene S/D contact. The NbS₂/n-MoS₂ MESFET with graphene was successfully integrated into an organic piezoelectric touch sensor circuit with green OLED indicator, exploiting its predictable small threshold voltage, while NbS₂/n-MoS₂ Schottky diodes with graphene were applied to extract doping concentrations in MoS₂ channel

Characterization of Rotational Stacking Layers in Large-Area MoSe₂ Film Grown by Molecular Beam Epitaxy and Interaction with Photon

Transition metal dichalcogenides (TMDCs) are promising next-generation materials for optoelectronic devices because, at subnanometer thicknesses, they have a transparency, flexibility, and band gap in the near-infrared to visible light range. In this study, we examined continuous, large-area MoSe₂ film, grown by molecular beam epitaxy on an amorphous SiO₂/Si substrate, which facilitated direct device fabrication without exfoliation. Spectroscopic measurements were implemented to verify the formation of a homogeneous MoSe₂ film by performing mapping on the micrometer scale and measurements at multiple positions. The crystalline structure of the film showed hexagonal (2H) rotationally stacked layers. The local strain at the grain boundaries was mapped using a geometric phase analysis, which showed a higher strain for a 30° twist angle compared to a 13° angle. Furthermore, the photon–matter interaction for the rotational stacking structures was investigated as a function of the number of layers using spectroscopic ellipsometry. The optical band gap for the grown MoSe₂ was in the near-infrared range, 1.24–1.39 eV. As the film thickness increased, the band gap energy decreased. The atomically controlled thin MoSe₂ showed promise for application to nanoelectronics, photodetectors, light emitting diodes, and valleytronics