Post-Degradation Recovery of CsPbI Quantum Dot Solar Cells.

The stability of perovskite quantum dot solar cells is one of the key challenges of this technology. This study reveals the unique degradation behavior of cesium lead triiodide (CsPbI) quantum dot solar cells. For the first time, it is shown that the oxygen-induced degradation and performance loss of CsPbI quantum dot photovoltaic devices can be reversed by exposing the degraded samples to humidity, allowing the performance to recover and even surpass the initial performance.

Dual Plasmons with Bioinspired 3D Network Structure Enabling Ultrahigh Efficient Solar Steam Generation.

Plasmonic nanomaterials such as Au, Ag, and Cu are widely recognized for their strong light-matter interactions, making them promising photothermal materials for solar steam generation. However, their practical use in water evaporation is significantly limited by the trade-off between high costs and poor stability. In this regard, we introduce a novel, nonmetallic dual plasmonic TiN/MoO composite.

Enhanced photocatalytic performance of coaxially electrospun titania nanofibers comprising yolk-shell particles.

The present paper reports the fabrication of novel types of hybrid fibrous photocatalysts by combining block copolymer (BCP) templating, sol-gel processing, and coaxial electrospinning techniques. Coaxial electrospinning produces core-shell nanofibers (NFs), which are converted into hollow porous TiO NFs using an oxidative calcination step. Hybrid BCP micelles comprising a single plasmonic nanoparticle (NP) in their core and thereof derived silica-coated core-shell particles are utilized as precursors to generate yolk-shell type particulate inclusions in photocatalytically active NFs.

Giant Blue Energy Harvesting in Two-Dimensional Polymer Membranes with Spatially Aligned Charges.

Blue energy between seawater and river water is attracting increasing interest, as one of the sustainable and renewable energy resources that can be harvested from water. Within the reverse electrodialysis applied in blue energy conversion, novel membranes with nanoscale confinement that function as selective ion transport mediums are currently in high demand for realizing higher power density. The primary challenge lies in constructing well-defined nanochannels that allow for low-energy barrier transport.

Development of oxidation-resistant and electrically conductive coating of Ti-Al-C system for the lightweight interconnects of solid oxide fuel cells.

The paper studies oxidation resistance and electrical conductivity of dense coatings produced by vacuum-arc deposition technique on α-titanium thin (0.1 mm) substrate using a hot pressed TiAlC-TiC target. The coatings were deposited at low (7 mA/cm) and high (15 mA/cm) current densities on the substrate and marked LCD and HCD, respectively.

Tunable Crystallinity and Electron Conduction in Wavy 2D Conjugated Metal-Organic Frameworks via Halogen Substitution.

Currently, most reported 2D conjugated metal-organic frameworks (2D c-MOFs) are based on planar polycyclic aromatic hydrocarbons (PAHs) with symmetrical functional groups, limiting the possibility of introducing additional substituents to fine-tune the crystallinity and electrical properties. Herein, a novel class of wavy 2D c-MOFs with highly substituted, core-twisted hexahydroxy-hexa-cata-benzocoronenes (HH-cHBCs) as ligands is reported. By tailoring the substitution of the c-HBC ligands with electron-withdrawing groups (EWGs), such as fluorine, chlorine, and bromine, it is demonstrated that the crystallinity and electrical conductivity at the molecular level can be tuned.

Tailoring the Morphology of a Diketopyrrolopyrrole-based Polymer as Films or Wires for High-Performance OFETs using Solution Shearing.

Conjugated polymers often show efficient charge carrier transport along their backbone which is a primary factor in the electrical behavior of Organic Field Effect Transistor (OFETs) devices fabricated from these materials. Herein, a solution shearing procedure is reported to fabricate micro/nano wires from a diketopyrrolopyrrole (DPP)-based polymer. Millimeter to nanometer long polymer wires orientated in the coating direction are developed after a thorough analysis of the deposition conditions.

Probing magnetic properties at the nanoscale: in-situ Hall measurements in a TEM.

We report on advanced in-situ magneto-transport measurements in a transmission electron microscope. The approach allows for concurrent magnetic imaging and high resolution structural and chemical characterization of the same sample. Proof-of-principle in-situ Hall measurements on presumably undemanding nickel thin films supported by micromagnetic simulations reveal that in samples with non-trivial structures and/or compositions, detailed knowledge of the latter is indispensable for a thorough understanding and reliable interpretation of the magneto-transport data.

Accessing parity-forbidden d-d transitions for photocatalytic CO reduction driven by infrared light.

A general approach to promote IR light-driven CO reduction within ultrathin Cu-based hydrotalcite-like hydroxy salts is presented. Associated band structures and optical properties of the Cu-based materials are first predicted by theory. Subsequently, Cu(SO)(OH) nanosheets were synthesized and are found to undergo cascaded electron transfer processes based on d-d orbital transitions under infrared light irradiation.

Recruiting Unicellular Algae for the Mass Production of Nanostructured Perovskites.

Functional capacities of lead halide perovskites are strongly dependent on their morphology, crystallographic texture, and internal ultrastructure on the nano- and the meso-scale. In the last decade, significant efforts are directed towards the development of novel synthesis routes that would overcome the morphological constraints provided by the physical and crystallographic properties of these materials. In contrast, various living organisms, such as unicellular algae, have the ability to mold biogenic crystals into a vast variety of intricate nano-architectured shapes while keeping their single crystalline nature.

Silver nanoparticle enhanced metal-organic matrix with interface-engineering for efficient photocatalytic hydrogen evolution.

Integrating plasmonic nanoparticles into the photoactive metal-organic matrix is highly desirable due to the plasmonic near field enhancement, complementary light absorption, and accelerated separation of photogenerated charge carriers at the junction interface. The construction of a well-defined, intimate interface is vital for efficient charge carrier separation, however, it remains a challenge in synthesis. Here we synthesize a junction bearing intimate interface, composed of plasmonic Ag nanoparticles and matrix with silver node via a facile one-step approach.

Ruthenium-Alloyed Iron Phosphide Single Crystal with Increased Fermi Level for Efficient Hydrogen Evolution.

Transition metal phosphide alloying is an effective approach for optimizing the electronic structure and improving the intrinsic performance of the hydrogen evolution reaction (HER). However, obtaining 3d transition metal phosphides alloyed with noble metals is still a challenge owing to their difference in electronegativity, and the influence of their electronic structure modulated by noble metals on the HER reaction also remains unclear. In this study, we successfully incorporated Ru into an FeP single crystal via the Bridgeman method and used it as a model catalyst, which effectively promoted HER.

Precise tuning of interlayer electronic coupling in layered conductive metal-organic frameworks.

Two-dimensional conjugated metal-organic frameworks (2D c-MOFs) have attracted increasing interests for (opto)-electronics and spintronics. They generally consist of van der Waals stacked layers and exhibit layer-depended electronic properties. While considerable efforts have been made to regulate the charge transport within a layer, precise control of electronic coupling between layers has not yet been achieved.

Size-Specific Magnetic Configurations in Electrodeposited Epitaxial Iron Nanocuboids: From Landau Pattern to Vortex and Single Domain States.

As the size of magnetic devices continuously decreases, the creation of three-dimensional nanomagnets and the understanding of their magnetic configurations become increasingly important for modern applications. Here, by progressive nucleation during epitaxial nanoelectrodeposition, we synthesize single-crystal iron nanocuboids with sizes ranging 10 to 200 nm on one sample. The size-dependent magnetic configurations of these nanocuboids are studied by quantitative magnetic force microscopy and electron holography.

Identification of Interface Structure for a Topological CoS Single Crystal in Oxygen Evolution Reaction with High Intrinsic Reactivity.

Transition metal chalcogenides such as CoS have been reported as competitive catalysts for oxygen evolution reaction. It has been well confirmed that surface modification is inevitable in such a process, with the formation of different re-constructed oxide layers. However, which oxide species should be responsible for the optimized catalytic efficiencies and the detailed interface structure between the modified layer and precatalyst remain controversial.

Controlled Silicidation of Silicon Nanowires Using Flash Lamp Annealing.

Among other new device concepts, nickel silicide (NiSi)-based Schottky barrier nanowire transistors are projected to supplement down-scaling of the complementary metal-oxide semiconductor (CMOS) technology as its physical limits are reached. Control over the NiSi phase and its intrusions into the nanowire is essential for superior performance and down-scaling of these devices. Several works have shown control over the phase, but control over the intrusion lengths has remained a challenge.

Chemically Stable Carbazole-Based Imine Covalent Organic Frameworks with Acidochromic Response for Humidity Control Applications.

Isoreticular chemically stable two-dimensional imine covalent organic frameworks (COFs), further denoted as DUT-175 and DUT-176, are obtained in a reaction of 4,4'-bis(9-carbazol-9-yl)biphenyl tetraaldehyde with phenyldiamine and benzidine. The crystal structures, solved and refined from the powder X-ray diffraction data and confirmed by high-resolution transmission electron microscopy, indicate AA-stacked layer structures. Both structures feature distorted hexagonal channel pores, assuring remarkable porosity ( = 1071 m g for DUT-175 and = 1062 m g for DUT-176), as confirmed by adsorption of gases and vapors.

Plasmon-assisted polarization-sensitive photodetection with tunable polarity for integrated silicon photonic communication systems.

To establish high-bandwidth chip-to-chip interconnects in optoelectronic integrated circuits, requires high-performance photon emitters and signal receiving components. Regarding the photodetector, fast device concepts like Schottky junction devices, large carrier mobility materials and shrinking the channel length will enable higher operation speed. However, integrating photodetectors in highly scaled ICs technologies is challenging due to the efficiency-speed trade-off.

Doped Organic Hole Extraction Layers in Efficient PbS and AgBiS Quantum Dot Solar Cells.

The efficiency of PbS quantum dot (QD) solar cells has significantly increased in recent years, strengthening their potential for industrial applications. The vast majority of state-of-the-art devices utilize 1,2-ethanedithiol (EDT)-coated PbS QD hole extraction layers, which lead to high initial performance, but result in poor device stability. While excellent performance has also been demonstrated with organic extraction layers, these devices include a molybdenum trioxide (MoO) layer, which is also known to decrease device stability.

Monolithic Metal-Semiconductor-Metal Heterostructures Enabling Next-Generation Germanium Nanodevices.

Low-dimensional Ge is perceived as a promising building block for emerging optoelectronic devices. Here, we present a wafer-scale platform technology enabling monolithic Al-Ge-Al nanostructures fabricated by a thermally induced Al-Ge exchange reaction. Transmission electron microscopy confirmed the purity and crystallinity of the formed Al segments with an abrupt interface to the remaining Ge segment.

Natural hybrid silica/protein superstructure at atomic resolution.

Formation of highly symmetric skeletal elements in demosponges, called spicules, follows a unique biomineralization mechanism in which polycondensation of an inherently disordered amorphous silica is guided by a highly ordered proteinaceous scaffold, the axial filament. The enzymatically active proteins, silicateins, are assembled into a slender hybrid silica/protein crystalline superstructure that directs the morphogenesis of the spicules. Furthermore, silicateins are known to catalyze the formation of a large variety of other technologically relevant organic and inorganic materials.

Intrinsic Activity of Oxygen Evolution Catalysts Probed at Single CoFeO Nanoparticles.

Identifying the intrinsic electrocatalytic activity of nanomaterials is challenging, as their characterization usually requires additives and binders whose contributions are difficult to dissect. Herein, we use nano impact electrochemistry as an additive-free method to overcome this problem. Due to the efficient mass transport at individual catalyst nanoparticles, high current densities can be realized.

Direct Observation of Plasmon Band Formation and Delocalization in Quasi-Infinite Nanoparticle Chains.

Chains of metallic nanoparticles sustain strongly confined surface plasmons with relatively low dielectric losses. To exploit these properties in applications, such as waveguides, the fabrication of long chains of low disorder and a thorough understanding of the plasmon-mode properties, such as dispersion relations, are indispensable. Here, we use a wrinkled template for directed self-assembly to assemble chains of gold nanoparticles.