Search

Garnet‐type solid‐state electrolytes are among the most reassuring candidates for the development of solid‐state lithium metal batteries (SSLMB) because of their wide electrochemical stability window and chemical feasibility with lithium. However, issues such as poor physical contact with Li metal tend to limit their practical applications. These problems were addressed using β‐SiC as an additive to the Li anode, resulting in improved wettability over Li6.75La3Zr1.75Ta0.25O12 (LLZTO) and establishing an improved interfacial contact. At the Li–SiC|LLZTO interface, intimacy was induced by a lithiophilic Li4SiO4 phase, whereas robustness was attained through the hard SiC phase. The optimized Li–SiC|LLZTO|Li–SiC symmetric cell displayed a low interfacial impedance of 10 Ω cm2 and superior cycling stability at varying current densities up to 5800 h. Moreover, the modified interface could achieve a high critical current density of 4.6 mA cm−2 at room temperature and cycling stability of 1000 h at 3.5 mA cm−2. The use of mechanically superior materials such as SiC as additives for the preparation of a composite anode may serve as a new strategy for robust garnet‐based SSLMB. [ABSTRACT FROM AUTHOR]

All‐solid‐state batteries with solid ionic conductors packed between solid electrode films can release the dead space between them, enabling a greater number of cells to stack, generating higher voltage to the pack. This Review is focused on using high‐voltage cathode materials, in which the redox peak of the components is extended beyond 4.7 V. Li−Ni−Mn−O systems are currently under investigation for use as the cathode in high‐voltage cells. Solid electrolytes compatible with the cathode, including halide‐ and sulfide‐based electrolytes, are also reviewed. Discussion extends to the compatibility between electrodes and electrolytes at such extended potentials. Moreover, control over the thickness of the anode is essential to reduce solid‐electrolyte interphase formation and growth of dendrites. The Review discusses routes toward optimization of the cell components to minimize electrode‐electrolyte impedance and facilitate ion transportation during the battery cycle. [ABSTRACT FROM AUTHOR]

The development of air cathodes for Li–O2 batteries is extensively studied, but focus on recycling Li–O2 batteries is still limited. Usually, the final death of Li–O2 batteries is caused by the accumulation of discharge products (Li2O2) on air cathodes which cannot be decomposed. Herein, we report an H2O-wash method that could regenerate air cathodes and pretreat them for air-cathode characterization. We successfully regenerated two kinds of air cathodes for at least five rounds without capacity fading. The structural and chemical/electrochemical changes of air cathodes could be easily observed owing to the removal of discharge products. Volume expansion and functionalized carbon were observed after regeneration. Finally, the used air cathodes could be utilized for CO2 capture, thereby reducing the impact of CO2 emission. This study aims to show that Li–O2 batteries can not only serve as a device of high energy density but also as a solution to a greener future. [ABSTRACT FROM AUTHOR]

Simple Summary: Measurable residual disease (MRD) monitoring is crucial in managing AML to predict the risk of relapse. A better understanding of which MRD technique and molecular target will have an effective clinical impact on AML is still required. Locked nucleic acid quantitative Real-Time PCR assay (LNA-qPCR) is sensitive and specific for quantifying oncogenetic single-nucleotide variation. We assessed the role of LNA-qPCR in the monitoring of IDH1/2 mutations MRD in eighty-eight AML patients from multiple centers. We found that IDH1/2 LNA-qPCR MRD correlates well with NPM1 qPCR MRD, predicts relapse-free survival and cumulative incidence of relapse, and is a potential MRD technique for IDH1/2-mutated AML patients with reduced IDH1/2 mutant levels after complete remission. Locked nucleic acid quantitative Real-Time PCR (LNA-qPCR) for IDH1/2 mutations in AML measurable residual disease (MRD) detection is rarely reported. LNA-qPCR was applied to quantify IDH1/2 mutants MRD kinetics in bone marrow from 88 IDH1/2-mutated AML patients, and correlated with NPM1-MRD, clinical characteristics, and outcomes. The median normalized copy number (NCN) of IDH1/2 mutants decreased significantly from 53,228 (range 87–980,686)/ALB × 106 at diagnosis to 773 (range 1.5–103,600)/ALB × 106 at first complete remission (CR). IDH1/2 LNA-qPCR MRD was concordant with remission status or NPM1-MRD in 79.5% (70/88) of patients. Younger patients and patients with FLT3 mutations had higher concordance. The Spearman correlation coefficient (rs) and concordance rate between the log reduction of IDH1/2 LNA-qPCR and NPM1-MRD were 0.68 and 81% (K = 0.63, 95% CI 0.50–0.74), respectively. IDH1/2-MRD > 2 log reduction at first CR predicted significantly better relapse-free survival (3-year RFS rates 52.9% vs. 31.9%, p = 0.007) and cumulative incidence of relapse (3-year CIR rates 44.5% vs. 64.5%, p = 0.012) compared to IDH1/2-MRD ≤ 2 log reduction. IDH1/2-MRD > 2 log reduction during consolidation is also associated with a significantly lower CIR rate than IDH1/2-MRD ≤ 2 log reduction (3-year CIR rates 42.3% vs. 68.8%, p = 0.019). LNA-qPCR for IDH1/2 mutation is a potential MRD technique to predict relapse in IDH1/2-mutated AML patients, especially for those with IDH1/2 MRD > 2 log reduction at first CR or a concurrent FLT3 mutation. [ABSTRACT FROM AUTHOR]

The design of high‐energy‐density batteries is the future goal of research on Li‐ion batteries. Halide‐type solid‐state electrolytes (SSEs) exceed their counterparts in terms of their stability at high potential. In this minireview, we discuss the developments in the work on halide‐type SSEs for all‐solid‐state Li batteries. In particular, we focus on the Li3InCl6 structure. The effect of synthesis routes on this structure, as well as the convertible products resulting from its phase changes, is discussed. Conductivity can be increased and the electrochemical window can be improved through doping with different materials. Our review aims to provide readers with an overview of the stability and degradation of Li3InCl6 SSE and the structure of halide‐type SSEs (Li–M–X, where M is a metal and X is a halogen). [ABSTRACT FROM AUTHOR]

While attention is focused on Li–CO2 batteries due to their high energy density and ability to utilize carbon, their detailed cathodic reaction mechanism remains unclear. Thus far, the recognized reaction formula involves CO2 reduction with carbon as the reduced product (3CO2 + 4Li+ + 4e− → 2Li2CO3 + C, E° = 2.8 V vs. Li+/Li). However, evidence of carbon formation is seldom provided in previous studies. The potential of the potential-determining step (CO2 + e− → CO2−, E° = 1.1 V vs. Li+/Li) in the reaction is much lower than the common working potential (2.6 V). Furthermore, the calculated redox potential at 2.8 V itself is incorrect since the calculation includes chemical reaction(s) that does not involve electron transfer. These findings do not suggest that the proposed cell reaction is correct. Herein, we propose that the previously observed reaction is caused by O2 and H2O participating in the electrochemical reaction to give such a high working potential. The formation of Li2CO3 as the only discharge product can support our statement through examination by soft X-ray absorption spectroscopy. Moreover, we find that the reaction of sole CO2 reduction can only happen at a low potential of 1.1 V with a current density of 100 mA g−1. CO, rather than C, is found to be the discharge product. Thus, both O2 and H2O contamination should be considered when studying Li–CO2 batteries, and the discharge product should be characterized carefully to claim the reaction formula. [ABSTRACT FROM AUTHOR]

Since the first commercialization of the "rocking chair" battery in the 1990s, the energy density of lithium-ion batteries has increased continuously. To reach higher energy density, the anode-free configuration has been suggested and intensively studied in recent years. In an anode-free battery, the Li deposits on the bare current collector (CC) in the first discharge without any host materials. Therefore, the anode-free configuration could be considered as a special kind of Li-metal battery. Although the anode-free design enhances the battery's energy density by decreasing network weight, the low coulombic efficiency (CE) and Li dendrite restrict the practical application. The interfacial issues, such as nonuniform deposition of lithium and parasitic reactions at the CC‖Li-metal‖electrolyte interfaces, are responsible for the low CE value and dendrite growth. To address these problems, tuning the CC‖Li-metal‖electrolyte interfacial chemistry has been considered as a promising approach. Diverse strategies have been used to modify the CC‖Li-metal‖electrolyte interfaces in the last few years. This review provides readers an overview of interfacial chemistry in anode-free batteries, including the interfacial problems and interfacial engineering strategies. Moreover, the interfacial modification strategies for the solid-state anode-free battery are also discussed. New approaches are expected to be developed to further improve the cycling stability of the anode-free batteries. [ABSTRACT FROM AUTHOR]

Limiting the carbon emission to the atmosphere requires the efficient utilization of carbonaceous gases and their capture via well‐designed platforms. Metal–CO2 batteries are currently being demonstrated as the route to utilize CO2 and produce energy simultaneously. In particular, Na–CO2 batteries are considered an alternative to Li‐batteries because of their abundance and low cost. In the current review, the developments in the field of Na–CO2 batteries are discussed. Carbon dioxide reactions to the decomposition of discharge products have been discussed elaborately. The main discharge products of Na–CO2 batteries are Na2CO3 and C. In the current review, various strategies are discussed to decompose the discharge products and hence improve cycle stability. The fraction of CO2 has a substantial influence on cell cycles. A plausible route of battery reaction can be drawn with the help of an ex situ analysis of the electrodes. The final part of the review focuses on the use of solid‐state Na‐ion conductors in Na–CO2 batteries. [ABSTRACT FROM AUTHOR]

The generation of clean energy is necessary for future technological developments. The utilization of solar illumination to produce H2 from water electrolysis is an alternative route to address the issue. However, the reaction is a thermodynamically uphill task. Furthermore, designing a photocathode, which can use most of the incident radiation for the photoelectrochemical (PEC) reaction, plays an important role. Surface-modified p-Si can be an economically viable option. The sluggish electro-kinetics on the Si surface has been rectified with coatings of cocatalyst materials. In the current review, we have discussed the possible modifications performed on the p-Si surface to reduce the loss due to reflection and coating of the cocatalyst, e.g. MoS2 on p-Si to improve H2 evolution. The facile charge carrier kinetics at the electrode–electrolyte interface has also been discussed. The development of cocatalysts has been focused on our previous experience for two decades. From surface plasmon resonance to heteroatom doping, that is, intentional defect formation and heterostructure design, we have included a comprehensive discussion on cocatalysts. The energetics of single atom replacement and its implications for efficiency has been included. This review gives insights into the currently emerging cocatalyst design for PEC water splitting. In this regard, the review presents insights into the phase transformation in MoS2 during the PEC process using operando techniques. A discussion on the effect of single atom replacement in the inactive basal-MoS2 plane has been included. [ABSTRACT FROM AUTHOR]

Near‐infrared (NIR) phosphors have gained a substantial amount of attention in the past few years simply due to their numerous applications. Recent publications have reported interesting findings regarding the fundamentals of phosphors. However, the unclear application of these phosphors limits their potential. This mini review aims to provide insights for researchers regarding the potential applications of NIR phosphors and their perspectives for further development of NIR phosphor technology. [ABSTRACT FROM AUTHOR]

Rechargeable Na–CO2 batteries are promising energy storage devices as they not only provide high energy density but also utilize earth-abundant Na and the greenhouse gas CO2. However, Na–CO2 battery development is deterred due to the sluggish electrochemical reactions at the cathode. The cathode catalyst is unable to decompose the insulating discharge product Na2CO3, thereby leading to increasing charge overpotential and poor cycle performance of the Na–CO2 battery. Herein, we report spinel ZnCo2O4 porous nanorods with multiwall carbon nanotubes (ZnCo2O4@CNT) as a cathode composite in the Na–CO2 batteries to effectively decompose Na2CO3 and improve the cycle performance. The battery shows stable discharge–charge for at least 150 cycles with a limited capacity of 500 mA h g−1 at 100 mA g−1. Moreover, the battery with the ZnCo2O4@CNT cathode catalyst exhibits a reversible discharge–charge capacity of 12 475 mA h g−1. Theoretical simulations suggest that the adsorption energies of CO2, Na, and Na2CO3 on the three surfaces of ZnCo2O4 are favorable for the CO2RR and CO2ER during the charge–discharge of the Na–CO2 battery. The surfaces of ZnCo2O4 investigated for catalytic activity include the [001] surface, the [111] surface with only exposed Co atoms, and the [111] surface with exposed Co and Zn atoms. The density of states calculation results further reveal that Co atoms on these three surfaces are possibly the catalytic active sites for the CO2RR and CO2ER during the charge–discharge of the Na–CO2 battery. [ABSTRACT FROM AUTHOR]

Phosphor-converted light-emitting diodes (LEDs) have recently become a promising candidate for next-generation devices used in agriculture and horticulture. In principle, they can overcome the limitations of regular daily sunshine. Here, the principle of LED-promoted plant growth was demonstrated by using the Ga2O3:Cr3+ phosphor with an extremely high quantum yield of 92.4%. The detailed structural and luminescent properties were characterized using X-ray diffraction, temperature-dependent photoluminescence, and pressure-dependent photoluminescence. The results reveal the unique two electronic spin-forbidden transition emissions (R1 and R2) of the Ga2O3:Cr3+ phosphor. Plant growth experiments were also conducted to evaluate the practical applications of the as-prepared phosphors, showing that they exhibit obvious positive effects on plants. This work reveals the important role of LEDs in agriculture and horticulture, as well as their potential practical applications. [ABSTRACT FROM AUTHOR]

Aims: The arcuate nucleus is a vital brain region for coursing of pain command. G protein-coupled kinase 6 (GRK6) accommodates signaling through G protein-coupled receptors. Studies have demonstrated that GRK6 is involved in inflammatory pain and neuropathic pain. The present study was designed to explore the role and the underlying mechanism of GRK6 in arcuate nucleus of chronic visceral pain. Methods: Chronic visceral pain of rats was induced by neonatal maternal deprivation and evaluated by monitoring the threshold of colorectal distension. Western blotting, immunofluorescence, real-time quantitative polymerase chain reaction techniques, and Nissl staining were employed to determine the expression and mutual effect of GRK6 with nuclear factor κB (NF-κB). Results: Expression of GRK6 in arcuate nucleus was significantly reduced in neonatal maternal deprivation rats when compared with control rats. GRK6 was mainly expressed in arcuate nucleus neurons, but not in astrocytes, and a little in microglial cells. Neonatal maternal deprivation reduced the percentage of GRK6-positive neurons of arcuate nucleus. Overexpression of GRK6 by Lentiviral injection into arcuate nucleus reversed chronic visceral pain in neonatal maternal deprivation rats. Furthermore, the expression of NF-κB in arcuate nucleus was markedly upregulated in neonatal maternal deprivation rats. NF-κB selective inhibitor pyrrolidine dithiocarbamate suppressed chronic visceral pain in neonatal maternal deprivation rats. GRK6 and NF-κB were expressed in the arcuate nucleus neurons. Importantly, overexpression of GRK6 reversed NF-κB expression at the protein level. In contrast, injection of pyrrolidine dithiocarbamate once daily for seven consecutive days did not alter GRK6 expression in arcuate nucleus of neonatal maternal deprivation rats. Conclusions: Present data suggest that GRK6 might be a pivotal molecule participated in the central mechanisms of chronic visceral pain, which might be mediated by inhibiting NF-κB signal pathway. Overexpression of GRK6 possibly represents a potential strategy for therapy of chronic visceral pain. [ABSTRACT FROM AUTHOR]

Li–air batteries are limited to lab‐scale research owing to the uninterrupted formation of discharge products. In the case of Li–CO2 batteries, the increase in overpotential caused by Li2CO3 formation results in cell death. In this study, Cu2O crystals having three different types of shapes (i.e., cubic, octahedral, and rhombic) were synthesized to compare their catalytic activity toward CO2 reactions. The full‐cycle and long‐term stability test revealed that rhombohedral Cu2O facilitates Li2CO3 decomposition more efficiently than that of cubic and octahedral Cu2O. The cycle was extended to investigate the photocatalytic activity of the rhombic Cu2O by illuminating the cell. The repeated cycles to 1 h showed a maximum overpotential of 1.5 V, which is 0.5 V lower than that of the cell without illumination. A postmortem analysis of the cell after dividing the cycles into segments demonstrated interesting results concerning the role of light and Cu2O during the cell cycle. [ABSTRACT FROM AUTHOR]

Lithium-ion (Li+) batteries suffer from problems caused by the chemical instability of their organic electrolytes. Solid-state electrolytes that exhibit high ionic conductivities and are stable to lithium metal are potential replacements for flammable organic electrolytes. Garnet-type Li7La3Zr2O12 is a promising solid-state electrolyte for next-generation solid-state Li batteries. In this study, we prepared mono-, dual-, and ternary-doped lithium (Li) garnets by doping tantalum (Ta), tantalum–barium (Ta–Ba), and tantalum–barium–gallium (Ta–Ba–Ga) ions, along with an undoped Li7La3Zr2O12 (LLZO) cubic garnet electrolyte, using a conventional solid-state reaction method. The effect of multi-ion doping on the Li+ dynamics in the garnet-type LLZO was studied by combining joint Rietveld refinement against X-ray diffraction and high-resolution neutron powder diffraction analyses with the results of Raman spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and multinuclear magic angle spinning nuclear magnetic resonance. Our results revealed that Li+ occupancy in the tetrahedrally coordinated site (24d) increased with increased multi-ion doping in LLZO, whereas Li+ occupancy in the octahedrally coordinated site (96h) remained constant. Among the investigated compounds, the ternary-doped garnet structure Li6.65Ga0.05La2.95Ba0.05Zr1.75Ta0.25O12 (LGLBZTO) exhibited the highest total ionic conductivity of 0.72 and 1.24 mS cm−1 at room temperature and 60 °C, respectively. Overall, our findings revealed that the dense microstructure and increased Li+ occupancy in the tetrahedral-24dLi1 site played a key role in achieving the maximum room-temperature Li-ion conductivity in the ternary-doped LGLBZTO garnet, and that the prepared ternary-doped LGLBZTO was a potential solid electrolyte for Li-ion batteries without polymer adhesion. [ABSTRACT FROM AUTHOR]

An integrated cobalt disulfide (CoS2) co-catalyst passivation layer on Si microwires (MWs) was used as a photocathode for solar hydrogen evolution. Si MWs were prepared by photolithography and dry etching techniques. The CoS2–Si photocathodes were subsequently prepared by chemical deposition and thermal sulfidation of the Co(OH)2 outer shell. The optimized onset potential and photocurrent of the CoS2–Si electrode were 0.248 V and −3.22 mA cm−2 (at 0 V), respectively. The best photocatalytic activity of the CoS2–Si electrode resulted from lower charge transfer resistances among the photoabsorber, co-catalyst, and redox couples in the electrolyte. X-ray absorption near edge structure was conducted to investigate the unoccupied electronic states of the CoS2 layer. We propose that more vacancies in the S-3p unoccupied states of the CoS2–Si electrode were present with a lower negative charge of S22− to form weaker S–H bond strength, promoting water splitting efficiency. Moreover, the CoS2 co-catalyst that completely covered underlying Si MWs served as a passivation layer to prevent oxidation and reduce degradation during photoelectrochemical measurements. Therefore, the optimal CoS2–Si electrode maintained the photocurrent at about −3 mA cm−2 (at 0 V) for 9 h, and its hydrogen generation rate was approximately 0.833 μmol min−1. [ABSTRACT FROM AUTHOR]

Development of a solar water splitting device requires design of a low-cost, efficient, and non-noble metal compound as alternative to noble metals. For the first time, we showed that CoSe2 can function as co-catalyst in phototoelectrochemical hydrogen production. We designed a heterostructure of p-Si and marcasite-type CoSe2 for solar-driven hydrogen production. CoSe2 successively coupled with p-Si can act as a superior photocathode in the solar-driven water splitting reaction. Photocurrents up to 9 mA cm−2 were achieved at 0 V vs. reversible hydrogen electrode. Electrochemical impedance spectroscopy showed that the high photocurrents can be attributed to low charge transfer resistance between the Si and CoSe2 interfaces and that between the CoSe2 and electrolyte interfaces. Our results suggest that this CoSe2 is a promising alternative co-catalyst for hydrogen evolution. [ABSTRACT FROM AUTHOR]

Development of a solar water splitting device requires design of a low-cost, efficient, and non-noble metal compound as alternative to noble metals. For the first time, we showed that CoSe2 can function as co-catalyst in phototoelectrochemical hydrogen production. We designed a heterostructure of p-Si and marcasite-type CoSe2 for solar-driven hydrogen production. CoSe2 successively coupled with p-Si can act as a superior photocathode in the solar-driven water splitting reaction. Photocurrents up to 9 mA cm−2 were achieved at 0 V vs. reversible hydrogen electrode. Electrochemical impedance spectroscopy showed that the high photocurrents can be attributed to low charge transfer resistance between the Si and CoSe2 interfaces and that between the CoSe2 and electrolyte interfaces. Our results suggest that this CoSe2 is a promising alternative co-catalyst for hydrogen evolution. [ABSTRACT FROM AUTHOR]

A new class of Mn4+ activated alkali-metal hexafluoride red phosphors are emerging for white light-emitting diodes because of their sharp red line 2Eg→4A2g emissions (600–650 nm) excited by irradiation of 4A2g→4T1g (320–380 nm) and 4A2g→4T2g (380–500 nm) transitions. However, these phosphors have the drawbacks of difficult control of the Mn valence state during synthesis and lack of underlying mechanisms for structure–photoluminescence relationships. In this study, we explore a novel, highly productive route to the quantifiable synthesis of K2GeF6:Mn4+ by the chemical co-precipitation method at room temperature. The prepared yellowish K2GeF6:Mn4+ powders exhibit a hexagonal shape and high crystallinity without significant defects. The photoluminescence thermal stability and white light-emitting diodes applicability of K2GeF6:Mn4+ suggest that it is a promising commercial red phosphor because of its efficient emission intensity, high color purity and excellent thermal stability. Structural analyses and theoretical calculations reveal that the red shift of the K2GeF6:Mn4+ red phosphor compared with K2SiF6:Mn4+ is due to the longer Ge–F distance and lower effective Mulliken charge of F ions in coordination environments of the MnF62− octahedron. The split feature in K2GeF6:Mn4+ is due to the hexagonal distortion in the host. The structure–photoluminescence mechanism is predicted to be general in hexafluoride red phosphors to tune the optical properties through cationic substitutions and crystal structure adjustments. [ABSTRACT FROM AUTHOR]

Nanophosphor GaZnON was synthesized by combustion using a unimolar mixture of metal oxides and urea as a flux/combustible agent at varying temperature and time; the resulting products crystallized in a single monoclinic phase and had broad PLE spectra (300–550 nm at λex = 350 nm) with the characteristic blue emission that can be utilised in white light-emitting diodes by adding them with red and green light-emitting phosphors and by using a UV LED (λex = 300 nm). Phosphors were examined according to respective package parameters. The blue light-emitting phosphor GaZnON was found to have excellent potential in white light-emitting diode devices by assimilating them with already viable red and green light-emitting phosphors and by stimulating them using a near-UV LED chip with wavelength λex = 300 nm. The possible electron transition mechanism responsible for the luminescence process is also discussed based on the experimental data. [ABSTRACT FROM AUTHOR]

Blue, green, and yellow phosphors are obtained in the Sr1−xY0.98+xCe0.02Si4N7−xCx system (x=0→1). Decreases in thermal quenching barrier height with x result from a dominant neighboring‐cation effect, through which the replacement of Sr2+ by Y3+ reduces the covalency of CeN bonding. Green emission is observed from a cation‐segregated nanostructure of SrYSi4N7 and Y2Si4N6C domains in x=0.2–0.6 samples. [ABSTRACT FROM AUTHOR]

Blaue, grüne und gelbe Leuchtmaterialien werden vom Sr1−xY0.98+xCe0.02Si4N7−xCx ‐ System (x=0→1) gebildet. Die Schwelle für die thermische Lumineszenzlöschung sinkt mit zunehmendem x. Ursache ist ein dominanter Nachbarkationeneffekt, der dazu führt, dass beim Ersatz von Sr2+ durch Y3+ die Kovalenz der Ce ‐ N ‐ Bindung gemindert wird. Die grüne Emission tritt bei einer kationensegregierten Nanostruktur von SrYSi4N7 ‐ und Y2Si4N6C ‐ Domänen in Proben mit x=0.2 – 0.6 auf. [ABSTRACT FROM AUTHOR]

The efficiency of hydrogen generation through photocatalytic water cleavage was elucidated for calcinated Cd-ZnGeON host systems. The electronic structures of the Cd-ZnGeON solid solution were explored via synchronized X-ray diffraction, X-ray absorption spectroscopy at the K-edge for elements O, N, Zn and Ge, X-ray photoelectron spectroscopy, diffuse reflection spectroscopy, and high-resolution transmission electron microscopy, etc., which were used as sensitive analytical probes. A good correlation was observed between the ability of Cd-ZnGeON for photocatalytic water splitting and the local atomic arrangement in its lattice. Based on advanced structural information about the solid solution, a concise lattice-model was proposed for hydrogen generation through water splitting. The electron-transfer route for hydrogen generation via photocatalytic water cleavage was also traced. The results reveal that the wurtzite Cd-ZnGeON calcinated at 600 °C generates a large amount of hydrogen (3647.25 μmol H2 h−1 g−1). [ABSTRACT FROM AUTHOR]

In this study, lithium phosphorus oxynitride (LiPON) thin films were deposited by radio frequency (r.f.) magnetron sputtering of a lithium phosphate (Li3PO4) target with various powers. The crystal structure, morphology, chemical environment, ionic conductivity, electronic state and coordination type were sequentially characterized by X-ray diffraction, scanning electron microscope, X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy and X-ray absorption spectroscopy, respectively. As the results, the optimal ionic conductivity was achieved by the r.f. power of 75 W. Furthermore, the P-N valence states of hybrid orbitals were increased with increasing the nitrogen amounts. [ABSTRACT FROM AUTHOR]

ABSTRACT A significant advance made in combinatorial approach research was that the emphasis shifted from simple mixing to intelligent screening, so as to improve the efficiency and accuracy of discovering new materials from a larger number of diverse compositions. In this study, the long-lasting luminescence of SrAl2O4, which is co-doped with Eu2+, Ce3+, Dy3+, Li+ and H3BO3, was investigated based on a combinatorial approach in conjunction with the Taguchi method. The minimal number of 16 samples to be tested (five dopants and four levels of concentration) were designed using the Taguchi method. The samples to be screened were synthesized using a parallel combinatorial strategy based on ink-jetting of precursors into an array of micro-reactor wells. The relative brightness of luminescence of the different phosphors over a particular period was assessed. Ce3+ was identified as the constituent that detrimentally affected long-lasting luminescence. Its concentration was optimized to zero. Li+ had a minor effect on long-lasting luminescence but the main factors that contributed to the objective property (long-lasting luminescence) were Eu2+, Dy3+ and H3BO3, and the concentrations of these dopants were optimized to 0.020, 0.030 and 0.300, respectively, for co-doping into SrAl2O4. This study demonstrates that the utility of the combinatorial approach for evaluating the effect of components on an objective property (e.g. phosphorescence) and estimating the expected performance under the optimal conditions can be improved by the Taguchi method. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Arrays of ZnO nanorods (NRs) were successfully converted into nanotubes (NTs), used as photoelectrodes in photoelectrochemical (PEC) cells after their sensitization with CdSe quantum dots (QDs) and a strong correlation between the PEC performance and geometrical structure of ZnO NTs@CdSe(QDs) and ZnO NRs@CdSe(QDs) was established under the same conditions. [ABSTRACT FROM AUTHOR]

The authors demonstrate a potential application of quantum dots for the detection of photons, showing that the Coulomb interaction resulting from the capture of photoexcited carriers by quantum dots produces a detectable change in the source-drain resistance of the transistor. This quantum effect is more pronounced with higher illumination, displaying staircase quantum steps with ΔV=4 mV on the I-V characteristics at room temperature, implying that the photocurrent is increased as the light intensity is increased. The responsitivity of device is R∼3.98×106 A/W for Vd=0.18 V, and external quantum efficiency is more than 8.6%. [ABSTRACT FROM AUTHOR]

The authors report here the enhanced luminescence properties of SrSi2O2N2 doped with Eu and M (M=Ce, Dy, and Mn). The Eu and Eu, Mn-codoped powders were prepared by a solid state reaction at temperatures between 1400 and 1600 °C under H2 (25%)–N2 (75%) atmosphere. The Eu, M-codoped Sr1-x-ySi2N2O2 phosphors have the monoclinic structure with lattice parameters a∼15.6 Å, b∼16.2 Å, c∼9.4 Å, and β∼91°. The phosphors can be efficiently excited in the UV to visible region, making them attractive as conversion phosphors for a light emitting diode application. A green-yellow emission was observed for Eu,M-codoped Sr1-x-ySi2N2O2. The addition of M in the Eu site in SrSi2O2N2 remarkably enhances the luminescent intensity by the factor of 144%, 148%, and 168% for Ce, Dy, and Mn, respectively. [ABSTRACT FROM AUTHOR]

A novel blue phosphor based on phosphate host matrix, KSrPO4 doped with Eu2+, was prepared by solid state reaction. The phosphor invariably emits blue luminescence with a peak wavelength at 424 nm under ultraviolet excitation at 360 nm. Eu2+-doped KSrPO4 phosphors show higher thermally stable luminescence which was found to be better than commercially available Y3Al5O12:Ce3+ phosphor at temperature higher than 225 °C. [ABSTRACT FROM AUTHOR]

A three-band white light-emitting diode (LED) was fabricated using an InGaN-based blue LED chip that emits 455 nm blue light, and green phosphor SrSi2O2N2:Eu and red phosphor CaSiN2:Ce that emit 538 nm green and 642 nm red emissions, respectively, when excited by the 455 nm blue light. The luminous efficacy of this white LED is about 30 lm/W at a dc of 20 mA. With increasing dc from 5.0 to 60 mA, both the coordinates x and y of the white LED tend to be the same, and consequently the Tc is the same and the Ra increases to 92.2. [ABSTRACT FROM AUTHOR]

In this letter, we shall describe a method, utilizing the proximity effect in electron beam lithography, suitable for fabricating silicon dots and devices, and demonstrate the electronic characteristics of the Si single-electron transistor. The drain current (Id) of the device oscillates against gate voltage. The electrical characteristics of the single-electron transistor were observed to be consistent with the expected behavior of electron transport through gated quantum dots, at up to 150 K. The dependence of the electrical characteristics on the dot size reveals that the Id oscillation follows from the Coulomb blockade by poly-Si grains in the poly-Si dot. The method of fabrication of this device is completely compatible with complementary metal–oxide–semiconductor technology, raising the possibility of manufacturing large-scale integrated nanoelectronic systems. [ABSTRACT FROM AUTHOR]