Effect of Discharge Gas Composition on SiC Etching in an HFE-347mmy/O/Ar Plasma.

This study explores the impact of varying discharge gas compositions on the etching performance of silicon carbide (SiC) in a heptafluoroisopropyl methyl ether (HFE-347mmy)/O/Ar plasma. SiC is increasingly favored for high-temperature and high-power applications due to its wide bandgap and high dielectric strength, but its chemical stability makes it challenging to etch. This research explores the use of HFE-347mmy as a low-global-warming-potential (GWP) alternative to the conventional high-GWP fluorinated gasses that are typically used in plasma etching.

Control of the Reaction Kinetics of Monodispersed InP/ZnSeSZnS-Based Quantum Dots Using Organophosphorus Compounds for Electroluminescent Devices.

Green emissive InP-based quantum dots (QDs) remain less developed than red QDs because of the difficulty of controlling the reactivity of small InP cores. Herein, we report the synthesis of monodispersed green InP-based QDs using tris(dimethylamino)phosphine, a considerably inexpensive and safer phosphorus source compared to conventional tris(trimethylsilyl)phosphine. An organophosphorus compound, trioctylphosphine, was used to control the reaction kinetics by slowing the progression of the nucleation process, which weakened the aggregation behavior of the clusters and improved the size distribution.

Effect of Secondary Structures on the Adsorption of Peptides onto Hydrophobic Solid Surfaces Revealed by SALDI-TOF and MD Simulations.

The adsorption of peptides and proteins on hydrophobic solid surfaces has received considerable research attention owing to their wide applications to biocompatible nanomaterials and nanodevices, such as biosensors and cell adhesion materials with reduced nanomaterial toxicity. However, fundamental understandings about physicochemical hydrophobic interactions between peptides and hydrophobic solid surfaces are still unknown. In this study, we investigate the effect of secondary structures on adsorption energies between peptides and hydrophobic solid surfaces via experimental and theoretical analyses using surface-assisted laser desorption/ionization-time-of-flight (SALDI-TOF) and molecular dynamics (MD) simulations.

Self-Assembled 4-Aminopyridine Monolayer as a Nucleation-Inducing Layer for Transparent Silver Electrodes.

The role of a self-assembled monolayer obtained by vacuum deposition of 4-aminopyridine (4-AP), a small organic molecule having amine and pyridine groups, as a metal nucleation inducer and adhesion promoter was verified, and the applicability was evaluated. 4-AP deposited to an extremely thin thickness effectively changed the substrate surface properties, increasing the nucleation density of silver (Ag) more than 3 times and eventually forming a more transparent, low-resistance Ag thin film. The optical transmittance of the Ag thin film, which was less than 60% when 4-AP was not applied, could be increased to about 77% by simply applying 4-AP, and the electrical resistance could be lowered from 37 to 14 Ω/square at the same time.

Precise and Prompt Analyte Detection via Ordered Orientation of Receptor in WSe-Based Field Effect Transistor.

Field-effect transistors (FET) composed of transition metal dichalcogenide (TMDC) materials have gained huge importance as biosensors due to their added advantage of high sensitivity and moderate bandgap. However, the true potential of these biosensors highly depends upon the quality of TMDC material, as well as the orientation of receptors on their surfaces. The uncontrolled orientation of receptors and screening issues due to crossing the Debye screening length while functionalizing TMDC materials is a big challenge in this field.

Supramolecular assembly of protein building blocks: from folding to function.

Several phenomena occurring throughout the life of living things start and end with proteins. Various proteins form one complex structure to control detailed reactions. In contrast, one protein forms various structures and implements other biological phenomena depending on the situation.

hBN Flake Embedded AlO Thin Film for Flexible Moisture Barrier.

Due to the vulnerability of organic optoelectronic devices to moisture and oxygen, thin-film moisture barriers have played a critical role in improving the lifetime of the devices. Here, we propose a hexagonal boron nitride (hBN) embedded AlO thin film as a flexible moisture barrier. After layer-by-layer (LBL) staking of polymer and hBN flake composite layer, AlO was deposited on the nano-laminate template by spatial plasma atomic layer deposition (PEALD).

Defect-Free Mechanical Graphene Transfer Using Doping Adhesive Gel Buffer.

The synthesis of uniform low-defect graphene on a catalytic metal substrate is getting closer to the industrial level. However, its practical application is still challenging due to the lack of an appropriate method for its scalable damage-free transfer to a device substrate. Here, an efficient approach for a defect-free, etchant-free, wrinkle-free, and large-area graphene transfer is demonstrated by exploiting a multifunctional viscoelastic polymer gel as a simultaneous shock-free adhesive and dopant layer.

Comparative toxicity of potential leachates from perovskite and silicon solar cells in aquatic ecosystems.

Globally, perovskite solar cells (PSCs) represent a third-generation photovoltaic technology that is being increasingly implemented and commercialized. However, the biological impacts of leachates from PSCs are poorly understood. Therefore, the aim of this study was to investigate the ecotoxicity of PSC leachates compared with that of commercial Si-based solar cell (SBSC) leachates.

Ion-Enhanced Etching Characteristics of sp-Rich Hydrogenated Amorphous Carbons in CF Plasmas and O Plasmas.

The sp-rich hydrogenated amorphous carbon (a-C:H) is widely adopted as hard masks in semiconductor-device fabrication processes. The ion-enhanced etch characteristics of sp-rich a-C:H films on ion density and ion energy were investigated in CF plasmas and O plasmas in this work. The etch rate of sp-rich a-C:H films in O plasmas increased linearly with ion density when no bias power was applied, while the fluorocarbon deposition was observed in CF plasmas instead of etching without bias power.

Enhancing the efficiency of solution-processed inverted quantum dot light-emitting diodes via ligand modification with 6-mercaptohexanol.

In this Letter, the surface hydrophilicity of the quantum dot (QD) emitting layer (EML) was modified via a ligand exchange to prevent QD EML damage upon hole transport layer (HTL) deposition for all-solution-processed inverted QD-light-emitting diodes (QLEDs). The conventional hydrophobic oleic acid ligand (OA-QDs) was partially replaced with a hydrophilic 6-mercaptohexanol (OH-QDs) through a one-pot ligand exchange. Owing to this replacement, the contact angle of a water droplet on the OH-QD films was reduced to 71.

Polyethylenimine-ethoxylated dual interfacial layers for highly efficient and all-solution-processed inverted quantum dot light-emitting diodes.

Inverted quantum dot light-emitting diodes (QLEDs) were fabricated through all-solution processing by sandwiching quantum dot (QD) emitting layers (EMLs) between dual polyethylenimine-ethoxylated (PEIE) layers. First, a PEIE layer as EML protecting layer (EPL) was formed on a QD EML to protect the EML from the hole transport layer (HTL) solvents and to facilitate the formation of a well-organized structure in the all-solution-processed inverted QLEDs. Second, another PEIE layer was introduced as an electron-blocking layer (EBL) on the zinc oxide (ZnO) electron transport layer (ETL) and effectively suppressed the excessive electron injection to the QD EML, thereby enhancing device efficiency.

Synthesis of Blue-Emissive InP/GaP/ZnS Quantum Dots via Controlling the Reaction Kinetics of Shell Growth and Length of Capping Ligands.

The development of blue-emissive InP quantum dots (QDs) still lags behind that of the red and green QDs because of the difficulty in controlling the reactivity of the small InP core. In this study, the reaction kinetics of the ZnS shell was controlled by varying the length of the hydrocarbon chain in alkanethiols for the synthesis of the small InP core. The reactive alkanethiol with a short hydrocarbon chain forms the ZnS shell rapidly and prevents the growth of the InP core, thus reducing the emission wavelength.

Phenethylamine ligand engineering of red InP quantum dots for improving the efficiency of quantum dot light-emitting diodes.

In this Letter, red-emitting multi-shelled indium phosphide (InP) quantum dots (QDs) were synthesized using the safe phosphorus precursor tris(dimethylamino)phosphine (()). The long-chain ligands of oleylamine (OAm) in the () phosphide source-based InP QDs were partially exchanged with short-chain ligands of phenethylamine (PEA) in the core formation process, and the resulting InP QDs were applied to quantum dot light-emitting diodes (QLEDs). The short-chain ligands of PEA with the -conjugated benzene ring improved the charge transport and electrical conduction of the QLEDs with () phosphide source-based InP QDs.

Composition-tailored ZnMgO nanoparticles for electron transport layers of highly efficient and bright InP-based quantum dot light emitting diodes.

Tailored-ZnMgO layers result in green-emitting InP based quantum dot light emitting diodes (QLEDs) with a maximum luminance of 13 900 cd m-2 and an external quantum efficiency (EQE) of 13.6%. This is the first report of green-emitting InP based QLEDs that exceed an EQE of 10% and a luminance of 13 000 cd m-2.

Interlayer doping with p-type dopant for charge balance in indium phosphide (InP)-based quantum dot light-emitting diodes.

A 2,3,4,6-tetrafluoro-7,7,8,8,-tetracyanoquinodimethane (F4-TCNQ) doping interlayer was developed to improve charge imbalance and the efficiency in indium phosphide (InP)-based quantum dot light-emitting diodes (QLEDs). The doping layer was coated between a hole injecting layer (HIL) and a hole transport layer (HTL) and successfully diffused with thermal annealing. This doping reduces the hole injection barrier and improves the charge balance of InP-based QLEDs, resulting in enhancement of an external quantum efficiency (EQE) of 3.

Stability and dispersion improvement of quantum-dot films by hydrosilylation between quantum-dot ligands and a siloxane matrix.

Quantum-dot (QD) ligands were modified and hydrosilylated with a siloxane matrix to improve the quantum efficiency and stability of the QDs. Conventional oleic acid (OA) ligands were exchanged with vinyl ligands without any reduction in the quantum yield. After ligand modification, hydrosilylation was induced between the vinyl ligands on the QDs (vinyl QDs) and a siloxane matrix, resulting in a uniform QD dispersion in the matrix.

High-Performance Transparent Quantum Dot Light-Emitting Diode with Patchable Transparent Electrodes.

Patchable electrodes are attractive for applications in optoelectronic devices because of their easy and reliable processability. However, development of reliable patchable transparent electrodes (TEs) with high optoelectronic performance is challenging; till now, optoelectronic devices fabricated with patchable TEs have been exhibiting limited performance. In this study, Ag nanowire (AgNW)/poly(methyl methacrylate) (PMMA) patchable TEs are developed and the highly efficient transparent quantum dot light-emitting diodes (QLEDs) using the patchable TEs are fabricated.

Hydrosilylation of Reactive Quantum Dots and Siloxanes for Stable Quantum Dot Films.

The reactive acrylate-terminated CdZnSeS/ZnS quantum dots (QDs) were designed and prepared by the effective synthetic route to bond with a siloxane matrix via hydrosilylation. The conventional QD with oleic acid ligands does not have any reactivity, so the QDs were functionalized to assign reactivity for the QDs by the ligand modification of two step reactions. The oleic acid of the QDs was exchanged for hydroxyl-terminated ligands as an intermediate product by one-pot reaction.

Charge balance control of quantum dot light emitting diodes with atomic layer deposited aluminum oxide interlayers.

We developed a 1.0 nm thick aluminum oxide (AlO) interlayer as an electron blocking layer to reduce leakage current and suppress exciton quenching induced by charge imbalance in inverted quantum dot light emitting diodes (QLEDs). The AlO interlayer was deposited by an atomic layer deposition (ALD) process that allows precise thickness control.

Experimental Investigation on Vertically Oriented Graphene Grown in a Plasma-Enhanced Chemical Vapor Deposition Process.

Vertically oriented graphene (VG) with three-dimensional architecture has been proved to exhibit unique properties, and its particular morphology has been realized by researchers to be crucial for its performance in practical applications. In this study, we investigated the morphology evolution of VG films synthesized by the plasma-enhanced chemical vapor deposition process, including porous graphene film, graphene wall, and graphene forest. This study reveals that the morphology of VG is controlled by a combination of the deposition and etching effects and tailored by the growth conditions, such as plasma source power and growth time and temperature.

Stability of Quantum Dots, Quantum Dot Films, and Quantum Dot Light-Emitting Diodes for Display Applications.

Quantum dots (QDs) are being highlighted in display applications for their excellent optical properties, including tunable bandgaps, narrow emission bandwidth, and high efficiency. However, issues with their stability must be overcome to achieve the next level of development. QDs are utilized in display applications for their photoluminescence (PL) and electroluminescence.

Surface Planarization of Low-Temperature Flowable Silicon Oxide for Atomic Layer Deposition Al₂O₃ Thin Film Encapsulation.

In this research, a flowable chemical vapor deposition (FCVD) process was developed to planarize particle-scattered surfaces for thin film encapsulation by atomic layer deposition (ALD). Nanometer-thick ALD layers are known to have good barrier properties owing to the conformal deposition of the films and their high density, but those barrier properties are vulnerable to degradation because of surface particles on the substrates. In this study, FCVD silicon oxide layer was applied to particlescattered surfaces as a planarization interlayer.