Hydrogen and Solid Carbon Production via Methane Pyrolysis in a Rotating Gliding Arc Plasma Reactor.

Plasma-induced methane pyrolysis is a promising hydrogen production method. However, few studies have focused the decomposition of pure methane as a discharge gas. Herein, a rotating gliding arc reactor was used for the conversion of methane (discharge gas and feedstock) into hydrogen and solid carbon.

Multimodal E-Textile Enabled by One-Step Maskless Patterning of Femtosecond-Laser-Induced Graphene on Nonwoven, Knit, and Woven Textiles.

Personal wearable devices are considered important in advanced healthcare, military, and sports applications. Among them, e-textiles are the best candidates because of their intrinsic conformability without any additional device installation. However, e-textile manufacturing to date has a high process complexity and low design flexibility.

Full-color micro-LED display with photo-patternable and highly ambient-stable perovskite quantum dot/siloxane composite as color conversion layers.

In this paper, we successfully fabricated color conversion layers (CCLs) for full-color-mico-LED display using a perovskite quantum dot (PQD)/siloxane composite by ligand exchanged PQD with silane composite followed by surface activation by an addition of halide-anion containing salt. Due to this surface activation, it was possible to construct the PQD surface with a silane ligand using a non-polar organic solvent that does not damage the PQD. As a result, the ligand-exchanged PQD with a silane compound exhibited high dispersibility in the siloxane matrix and excellent atmospheric stability due to sol-gel condensation.

Hierarchically Porous, Laser-Pyrolyzed Carbon Electrode from Black Photoresist for On-Chip Microsupercapacitors.

We report a laser-pyrolyzed carbon (LPC) electrode prepared from a black photoresist for an on-chip microsupercapacitor (MSC). An interdigitated LPC electrode was fabricated by direct laser writing using a high-power carbon dioxide (CO) laser to simultaneously carbonize and pattern a spin-coated black SU-8 film. Due to the high absorption of carbon blacks in black SU-8, the laser-irradiated SU-8 surface was directly exfoliated and carbonized by a fast photo-thermal reaction.

Highly Efficient and Air-Stable Heterostructured Perovskite Quantum Dot Solar Cells Using a Solid-State Cation-Exchange Reaction.

Perovskite quantum dots (PQDs) have expanded the scalability of perovskite materials by their high crystallinity, band-gap tunability, and surface ligand-driven functionalities in the colloidal state across optoelectronics as well as photovoltaics. To improve PQD performance in applications, however, defect control has emerged as a major challenge given the increased PQD surface area. Herein, we have developed a heterostructured PQD solar cell by combining CsPbI and FAPbI (FA, formamidinium) PQD layers to introduce a multinary PQD layer based on a solid-state A-site cation-exchange strategy.

Angle-Insensitive Transmission and Reflection of Nanopatterned Dielectric Multilayer Films for Colorful Solar Cells.

Aesthetically appealing photovoltaic (PV) panels with colorful layers are used in numerous applications involving color matching with the surroundings. To develop a colored film for a PV system, appropriate optical properties such as high transparency and low angle sensitivity are necessary because the colored layers can reduce the efficiency of the PV system by causing variations in the transmittance and angle of incidence. Herein, we propose a facile fabrication method for bioinspired three-dimensional (3D) photonic crystal (PC) films that exhibit broad angle-insensitive transmission and reflection, for application in colorful PV.

Direct-Contact Microelectrical Measurement of the Electrical Resistivity of a Solid Electrolyte Interface.

Because of its effectiveness in blocking electrons, the solid electrolyte interface (SEI) suppresses decomposition reactions of the electrolyte and contributes to the stability and reversibility of batteries. Despite the critical role of SEI in determining the properties of batteries, the electrical properties of SEI layers have never been measured directly. In this paper, we present the first experimental results of the electrical resistivity of a LiF-rich SEI layer measured using a direct-contact microelectrical device mounted in an electron microscope.

Conversion Reaction of Nanoporous ZnO for Stable Electrochemical Cycling of Binderless Si Microparticle Composite Anode.

Binderless, additiveless Si electrode design is developed where a nanoporous ZnO matrix is coated on a Si microparticle electrode to accommodate extreme Si volume expansion and facilitate stable electrochemical cycling. The conversion reaction of nanoporous ZnO forms an ionically and electrically conductive matrix of metallic Zn embedded in LiO that surrounds the Si microparticles. Upon lithiation, the porous LiO/Zn matrix expands with Si, preventing extensive pulverization, while Zn serves as active material to form Li Zn to further enhance capacity.

Highly-Stable Li₄Ti₅O Anodes Obtained by Atomic-Layer-Deposited Al₂O₃.

LTO (Li₄Ti₅O) has been highlighted as anode material for next-generation lithium ion secondary batteries due to advantages such as a high rate capability, excellent cyclic performance, and safety. However, the generation of gases from undesired reactions between the electrode surface and the electrolyte has restricted the application of LTO as a negative electrode in Li-ion batteries in electric vehicles (EVs) and energy storage systems (ESS). As the generation of gases from LTO tends to be accelerated at high temperatures (40⁻60 °C), the thermal stability of LTO should be maintained during battery discharge, especially in EVs.

Carbon Textile Decorated with Pseudocapacitive VC/V O for High-Performance Flexible Supercapacitors.

It is demonstrated that, via V O coating by low temperature atomic layer deposition and subsequent pyrolysis, ubiquitous cotton textile can readily turn into high-surface-area carbon textile fully decorated with pseudocapacitive V O /VC widely usable as electrodes of high-performance supercapacitor. It is found that carbothermic reduction of V O (C + V O → C' + VC + CO/CO (g)) leads to chemical/mechanical activation of carbon textile, thereby producing high-surface-area conductive carbon textile. In addition, sequential phase transformation and carbide formation (V O → V O → VC) occurred by carbothermic reduction trigger decoration of the carbon textile with redox-active V O /VC.

Nanospherical solid electrolyte interface layer formation in binder-free carbon nanotube aerogel/Si nanohybrids to provide lithium-ion battery anodes with a long-cycle life and high capacity.

Silicon anodes for lithium ion batteries (LiBs) have been attracting considerable attention due to a theoretical capacity up to about 10 times higher than that of conventional graphite. However, huge volume expansion during the cycle causes cracks in the silicon, resulting in the degradation of cycling performance and eventual failure. Moreover, low electrical conductivity and an unstable solid electrolyte interface (SEI) layer resulting from repeated changes in volume still block the next step forward for the commercialization of the silicon material.

Observation of partial reduction of manganese in the lithium rich layered oxides, 0.4LiMnO-0.6LiNiCoMnO, during the first charge.

Lithium-rich layered oxides show promise as high-energy harvesting materials due to their large capacities. However, questions remain regarding the large irreversible loss in capacities for the first charge-discharge cycle due to oxygen removal in lattices related to layered LiMnO. Herein we present detailed studies on Li-rich Mn-based layered oxides of 0.

One-Step Deposition of Photovoltaic Layers Using Iodide Terminated PbS Quantum Dots.

We present a one-step layer deposition procedure employing ammonium iodide (NH4I) to achieve photovoltaic quality PbS quantum dot (QD) layers. Ammonium iodide is used to replace the long alkyl organic native ligands binding to the QD surface resulting in iodide terminated QDs that are stabilized in polar solvents such as N,N-dimethylformamide without particle aggregation. We extensively characterized the iodide terminated PbS QD via UV-vis absorption, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), FT-IR transmission spectroscopy, and X-ray photoelectron spectroscopy (XPS).

Thermal Cycling Behavior of Zinc Antimonide Thin Films for High Temperature Thermoelectric Power Generation Applications.

The zinc antimonide compound ZnxSby is one of the most efficient thermoelectric materials known at high temperatures due to its exceptional low thermal conductivity. For this reason, it continues to be the focus of active research, especially regarding its glass-like atomic structure. However, before practical use in actual surroundings, such as near a vehicle manifold, it is imperative to analyze the thermal reliability of these materials.

All-solution-processed PbS quantum dot solar modules.

A rapid increase in power conversion efficiencies in colloidal quantum dot (QD) solar cells has been achieved recently with lead sulphide (PbS) QDs by adapting a heterojunction architecture, which consists of small-area devices associated with a vacuum-deposited buffer layer with metal electrodes. The preparation of QD solar modules by low-cost solution processes is required to further increase the power-to-cost ratio. Herein we demonstrate all-solution-processed flexible PbS QD solar modules with a layer-by-layer architecture comprising polyethylene terephthalate (PET) substrate/indium tin oxide (ITO)/titanium oxide (TiO2)/PbS QD/poly(3-hexylthiophene) (P3HT)/poly(3,4-ethylenedioxythiophene) : poly(styrene sulfonate) (PEDOT : PSS)/Ag, with an active area of up to 30 cm(2), exhibiting a power conversion efficiency (PCE) of 1.

Controlled assembly of CdSe/MWNT hybrid material and its fast photoresponse with wavelength selectivity.

We report the novel assembly method of CdSe quantum dot (QD)/pyridine/multi-walled carbon nanotube (CdSe-py-MWNT) hybrid material between electrodes using two-step dielectrophoresis (DEP). At the first step, we assembled the individual MWNT between electrodes by the DEP method. At the second step, the CdSe-py materials were assembled onto the MWNT by DEP method again, which enables site specific and density controlled assembly of QDs.

Efficient fabrication of wafer scale thin film of individualized single-walled carbon nanotubes by dual-nozzle spin casting.

In this paper, a dual-nozzle spin casting method was proposed to form a thin film of individualized single-walled carbon nanotubes (SWNTs) at the wafer scale. Each nozzle simultaneously ejected the SWNT solution and methanol, respectively. During the ejection process, two solutions were mixed at the contacting end of the nozzles and then dropped onto the substrate.

Efficient electron transfer in functional assemblies of pyridine-modified NQDs on SWNTs.

Nanocrystal quantum dot (NQD)/single-walled carbon nanotube (SWNT) hybrid nanomaterials were synthesized, assembled into field effect transistors (FETs) via dielectrophoresis (DEP), and characterized optically and electronically. The pyridine moiety functioned as a short, noncovalent linker between the NQDs and SWNTs and allowed more efficient carrier transfer through the assemblies without deleteriously altering electronic structures. Photoluminescence studies of the resulting assemblies support an efficient carrier transfer process in CdSe-py-SWNTs unlike that of CdSe/ZnS-py-SWNTs.

Deterministic fabrication of carbon nanotube probes using the dielectrophoretic assembly and electrical detection.

We report the controlled dielectrophoretic assembly for the deterministic fabrication of carbon nanotube (CNT) probes. Electrical detection was applied to the dielectrophoretic assembly of CNT probes. Dielectrophoretic manipulation with an ac electric field of 5 MHz was used to form the CNT bridge across oppositely aligned tungsten tips (W-tips).

Preferential elimination of metallic single-walled carbon nanotubes using microwave irradiation.

This study presents a simple, easy and rapid technique for the preferential destruction of metallic single-walled carbon nanotubes (m-SWNTs) using microwave irradiation. The proportion of m-SWNTs in a randomly networked film that were made of pristine SWNTs was gradually reduced with microwave irradiation of 1000 W at 2.45 GHz ranging from 0 to 20 min.

Continuous extraction of highly pure metallic single-walled carbon nanotubes in a microfluidic channel.

Highly pure metallic single-walled carbon nanotubes were continuously extracted from a mixture of semiconducting and metallic species using a nondestructive, scalable method. Two laminar streams were generated in an H-shaped microfluidic channel with two inlets and two outlets. The flow conditions were carefully controlled to minimize diffusive and convective transport across the boundary between the two flows.