Spray-Printed Flexible LiS Cathode with Inorganic Ion-Conductive Binder Nano-LiPS.

Flexible solid-state batteries fabricated by printing techniques are promising integrated power supplies for miniaturized and customized electronic devices. While typically these batteries use polymer solid electrolytes, a flexible LiS cathode with sulfide solid electrolyte is spray-printed in this work, by using solvated LiPS nanoparticles as inorganic ion-conductive binder. This benefits from a novel low-temperature-sintering property of these nanoparticles, which can be pressure-free densified, along with the desolvation process, and thus bind the cathode at 250 °C.

Ionic Conductivity and Structure of Glasses Synthesized by Mechanical-Milling Methods in the [NaS]-(100 - ) [0.5GeS-0.5GaS] System.

Chalcogenide glasses in the NaS-GeS-GaS pseudoternary system were synthesized using a combination route of melt-quenching and mechanical-milling methods. First, a glass rich in germanium (90GeS-10GaS) is synthesized by melt-quenching synthesis in a silica tube sealed under vacuum. This glass is used as a precursor for the second step of mechanochemistry to explore the NaS-GeS-GaS pseudoternary system.

Mechanochemical Synthesis and Study of the Local Structure of NaGaS Glass and Glass-Ceramics.

NaGaS is a newly discovered compound that has already shown great promise for a variety of applications because of its layered structure and ion exchange properties. In this work, crystalline NaGaS has been synthesized by an alternative method to what has been previously published, namely, by mechanochemistry, either by a direct one-step process or by a two-step process. In the one-step process, crystalline NaGaS is directly formed by milling sodium sulfide NaS and gallium(III) sulfide GaS.

New Chalcogenide Glass-Ceramics Based on Ge-Zn-Se for IR Applications.

The consumer market requests infrared (IR) optical components, made of relatively abundant and environmentally friendly materials, to be integrated or attached to smartphones. For this purpose, three new chalcogenides samples, namely GeZnSe (d_GZSe-1), GeZnSe (d_GZSe-2) and BaGeZnSeI (d_GZSe-3) were obtained by mechanical alloying and processed by spark plasma sintering into dense bulk disks. Obtaining a completely amorphous and homogeneous material proved to be difficult.

Improving Cycling Stability of the Lithium Anode by a Spin-Coated High-Purity LiPS Artificial SEI Layer.

Controlling the composition and microstructure of the solid electrolyte interphase (SEI) layer is critical to improving the cycling stability of the high-energy-density lithium-metal electrode. It is a quite tricky task to control the properties of the SEI layer which is conventionally formed by the chemical reactions between a Li metal and the additives. Herein, we develop a new route to synthesize a lithium-compatible sol of the sulfide electrolyte LiPS, so that a LiPS artificial SEI layer with a controllable nanoscale thickness and high phase purity can be prepared by spin-coating.

Deformation mechanism of a metal-organic framework glass under indentation.

Revealing the deformation mechanism of brittle materials under sharp contact loading (indentation) is important for their applications since this knowledge is crucial for identifying the origin of flaw and scratch formation on their surfaces. As a newly emerged glass family, metal-organic framework (MOF) glasses have not been studied concerning the mechanism of their indentation-induced deformation. Here, we explore this mechanism for ZIF-62 glass (a typical MOF glass system).

IR GRIN lenses prepared by ionic exchange in chalcohalide glasses.

In order to decrease the number of lenses and the weight of thermal imaging devices, specific optical design are required by using gradient refractive index (GRIN) elements transparent in the infrared waveband. While widely used for making visible GRIN lenses with silicate glasses, the ion exchange process is very limited when applied to chalcogenide glasses due to their low T and relatively weak mechanical properties. In this paper, we develop chalco-halide glasses based on alkali halide (NaI) addition in a highly covalent GeSe-GaSe matrix, efficient for tailoring a significant and permanent change of refractive by ion exchange process between K and Na.

Structural and chemical homogeneity of chalcogenide glass prepared by melt-rocking.

The chemical and structural homogeneity of selenide glasses produced by mechanical homogenization of the melt in a rocking furnace is investigated by Raman and Energy Dispersive Spectroscopy (EDS). Both techniques demonstrate that the glass is macroscopically homogeneous along the entire length of a 6 cm rod. EDS imaging performed over four orders of magnitude in scale further confirms that the glass is homogeneous down to the sub-micron scale.

Broadband blue emission from ZnO amorphous nanodomains in zinc phosphate oxynitride glass.

ZnO amorphous nanostructures in a glass matrix show unique optical properties. However, although a ZnO amorphous nanostructure can be formed in some settled multicomponent silicate glasses, the intensity of its emission is extremely weak. Here, to the best of our knowledge, we report a novel and simple zinc phosphate oxynitride glass that can display strong broadband blue emission with a short decay time due to the ZnO amorphous nanostructure in the glass matrix.

Short and medium range structures of 80GeSe-20GaSe chalcogenide glasses.

The short and medium range structures of 80GeSe-20GaSe (or GeGaSe) chalcogenide glasses have been studied by combining ab initio molecular dynamics (AIMD) simulations and experimental neutron diffraction studies. The structure factor and total correlation function were calculated from glass structures generated from AIMD simulations and compared with neutron diffraction experiments showing reasonable agreement. The atomic structures of ternary chalcogenide glasses were analyzed in detail, and it was found that gallium atoms are four-fold coordinated by selenium (Se) and form [GaSe] tetrahedra.

Ga-Se connectivities and proximities in gallium selenide crystal and glass probed by solid-state NMR.

We introduce two-dimensional (2D) Ga-Se through-bond and through-space correlation experiments. Such correlations are achieved using (i) the J-mediated Refocused Insensitive Nuclei Enhanced by Polarization Transfer (J-RINEPT) method with Ga excitation and Se Carr-Purcell-Meiboon-Gill (CPMG) detection, as well as (ii) the J- or dipolar-mediated Hetero-nuclear Multiple-Quantum Correlation (J- or D-HMQC) schemes with Ga excitation and quadrupolar CPMG (QCPMG) detection. These methods are applied to the crystalline β-GaSe and the 0.

'Cold' crystallization in nanostructurized 80GeSe2-20Ga2Se3 glass.

'Cold' crystallization in 80GeSe2-20Ga2Se3 chalcogenide glass nanostructurized due to thermal annealing at 380°C for 10, 25, 50, 80, and 100 h are probed with X-ray diffraction, atomic force, and scanning electron microscopy, as well as positron annihilation spectroscopy performed in positron annihilation lifetime and Doppler broadening of annihilation line modes. It is shown that changes in defect-related component in the fit of experimental positron lifetime spectra for nanocrystallized glasses testify in favor of structural fragmentation of larger free-volume entities into smaller ones. Nanocrystallites of Ga2Se3 and/or GeGa4Se8 phases and prevalent GeSe2 phase extracted mainly at the surface of thermally treated samples with preceding nucleation and void agglomeration in the initial stage of annealing are characteristic features of cold crystallization.

Photonic Bandgap Propagation in All-Solid Chalcogenide Microstructured Optical Fibers.

An original way to obtain fibers with special chromatic dispersion and single-mode behavior is to consider microstructured optical fibers (MOFs). These fibers present unique optical properties thanks to the high degree of freedom in the design of their geometrical structure. In this study, the first all-solid all-chalcogenide MOFs exhibiting photonic bandgap transmission have been achieved and optically characterized.

Halo-tellurite glass fiber with low OH content for 2-5µm mid-infrared nonlinear applications.

We report the fabrication of new dehydrated halo-tellurite glass fibers with low OH content (1ppm in weight) and low OH-induced attenuation of 10dB/m in 3-4 µm region. It shows halo-tellurite glass fibers a promising candidate for nonlinear applications in 2-5µm region.

An innovative approach to develop highly performant chalcogenide glasses and glass-ceramics transparent in the infrared range.

An innovative way to produce chalcogenide glasses and glass-ceramics for infrared devices is reported. This new method of synthesis at low temperature combining ball-milling and sintering by SPS (Spark Plasma Sintering) is a technological breakthrough to produce efficient infrared chalcogenide glasses and glass-ceramics. This technique will offer the possibility to strongly decrease the cost of infrared devices and to produce new chalcogenide glasses.

Free carrier accumulation during direct laser writing in chalcogenide glass by light filamentation.

We present direct laser writing of channels in chalcogenide glass under light filamentation conditions. Because of the intrinsic properties of the filament, the positive refractive index profile of the channels exhibits a cylindrical symmetry of high quality. The role of the repetition rate is also investigated.

Reversible giant photocontraction in chalcogenide glass.

It is shown that chalcogenide glasses with suitably underconstrained network can undergo reversible giant photocontractions up to a micron depth. These effects result from the combination of two attributes particular to these glasses, (i) the high photosensitivity characteristic of low coordination floppy networks and (ii) the wide window of structural configuration characteristic of fragile glass former. Interestingly these effects are reversible and subsequent irradiation with high intensity results in giant photoexpansion in the same glass.

Second-order optical nonlinearity and ionic conductivity of nanocrystalline GeS2-Ga2S3-LiI glass-ceramics with improved thermo-mechanical properties.

IR-transparent chalcogenide glass-ceramics were fabricated through a careful ceramization process of the as-prepared 65 GeS(2) x 25 Ga(2)S(3) x 10 LiI glasses at a temperature of 403 degrees C for various durations. Owing to the precipitation of Li(x)Ga(y)S(z) crystals with a Ga(2)S(3)-like structure, clear second-harmonic generation was observed in the sample crystallized at 403 degrees C for 60 h, which has a greatly improved resistance to environmental impairment. Additionally, it is found that the shorter crystallization process (< or = 60 h) contributed to the enhancement of Li(+) ionic conductivity, whereas a longer heat-treatment (80 h) would impair that of the glass-ceramics.

Structural investigations of glass ceramics in the Ga(2)S(3)-GeS(2)-CsCl system.

Transparent glass ceramics have been prepared in the Ga(2)S(3)-GeS(2)-CsCl pseudoternary system using appropriate heat treatment time and temperature. In situ X-ray diffraction at the heat treatment temperature and (133)Cs and (71)Ga solid-state nuclear magnetic resonance have been performed in function of annealing time to understand the crystallization process. Both techniques have evidenced the nucleating agent role played by gallium with the formation of Ga(2)S(3) nanocrystals.

Planar waveguide obtained by burying a Ge22As(20Se58 fiber in As2S3 glass.

We demonstrate the possibility of fabricating an infrared transmitting waveguide by burying fiber in chalcogenide glasses. Two highly mature chalcogenide glasses are used for these experiments. GASIR glass from Umicore IR Glass, Olen, Belgium, with the composition of Ge(22)As(20)Se(58) is used to draw fibers that are then buried in an As(2)S(3) glass substrate.

Light-induced matrix softening of Ge-As-Se network glasses.

Sub-band-gap irradiation of a series of bulk Ge-As-Se glass samples with a tunable laser source shows that photostructural processes in chalcogenide glasses are strongly dependent on the covalent network connectivity. The photoexcitation process is affected by the bond density as well as the network rigidity. Photostructural changes such as photodarkening and photoexpansion decrease and tend to vanish in overcoordinated glass in accordance with the rigidity percolation threshold.