Search results for "chalcogenide"
showing 10 items of 141 documents
Elaboration of multimaterial optical fibers with electro-optical functionalities
2022
The emergence of multimaterials optical fibers is of tremendous technological interest in photonics to combine the remarkable properties of glasses with those of other materials such as metals or polymers in order to form a fully integrated fiber optical system with multiple functionalities. Among these hybrid fibers, the development of fibers combining both optical signal and simultaneous electrical transport function could bring alternative interesting solution in many fields such as telecommunications, medicine or sensing. The drawing of architectures merging electrical and optical features in a unique elongated wave-guiding structure will enable to develop electro-optical functionalitie…
Strong absorption and ultrafast localisation in NaBiS2 nanocrystals with slow charge-carrier recombination.
2022
Funder: AiF Project, no: ZIM-KK5085302DF0
Application of 2D Non-Graphene Materials and 2D Oxide Nanostructures for Biosensing Technology
2016
The discovery of graphene and its unique properties has inspired researchers to try to invent other two-dimensional (2D) materials. After considerable research effort, a distinct "beyond graphene" domain has been established, comprising the library of non-graphene 2D materials. It is significant that some 2D non-graphene materials possess solid advantages over their predecessor, such as having a direct band gap, and therefore are highly promising for a number of applications. These applications are not limited to nano- and opto-electronics, but have a strong potential in biosensing technologies, as one example. However, since most of the 2D non-graphene materials have been newly discovered,…
Selenium Nanoparticles Synthesized via a Facile Hydrothermal Method
2012
Crystalline selenium nanostructures were synthesized from the reaction of a GeSe3 glass with water at 85°C for 144 hours. The hydrolysis of the Ge-Se bonds releases Se fragments in the solution where they form a colloidal suspension of amorphous nanospheres. The later evolve toward a more stable hexagonal phase (trigonal) leading to the anisotropic growth of one-dimensional monocrystalline structures. Filaments, bars and tubes of monocrystalline trigonal selenium were obtained with diameters ranging from 10 nm to 1 µm and aspect ratio up to 180. This simple process in aqueous solution opens new perspectives for the synthesis of 1D nanoparticles of trigonal selenium at large scale.
Catalyst-free vapour-solid technique for deposition of Bi2Te3 and Bi2Se3 nanowires/nanobelts with topological insulator properties.
2015
We present a simple two-stage vapour–solid synthesis method for the growth of bismuth chalcogenide (Bi2Te3, Bi2Se3) topological insulator nanowires/nanobelts by using Bi2Se3 or Bi2Te3 powders as source materials. During the first stage of the synthesis process nanoplateteles, serving as “catalysts” for further nanowire/nanobelt growth, are formed. At a second stage of the synthesis, the introduction of a N2 flow at 35 Torr pressure in the chamber induces the formation of free standing nanowires/nanobelts. The synthesised nanostructures demonstrate a layered single-crystalline structure and Bi : Se and Bi : Te ratios 40 : 60 at% for both Bi2Se3 and Bi2Te3 nanowires/nanobelts. The presence of…
Molecular Camouflage: Making Use of Protecting Groups To Control the Self-Assembly of Inorganic Janus Particles onto Metal-Chalcogenide Nanotubes by …
2011
Hard and soft: Binding of inorganic Pt@Fe3O4 Janus particles to WS2 nanotubes through their Pt or Fe3O4 domains is governed by the difference in Pearson hardness: the soft Pt block has a higher sulfur affinity than the harder magnetite face; thus the binding proceeds preferentially through the Pt face. This binding preference can be reversed by masking the Pt face with an organic protecting group.
Effect of ion irradiation on the stability of amorphous Ge2Sb2Te5 thin films
2008
The archival life of phase-change memories (PCM) is determined by the thermal stability of amorphous phase in a crystalline matrix. In this paper, we report the effect of ion beam irradiation on the crystallization kinetics of amorphous Ge2Sb2Te5 alloy (GST). The transition rate of amorphous GST films was measured by in situ time resolved reflectivity (TRR). The amorphous to crystal transformation time decreases considerably in irradiated amorphous GST samples when ion fluence increases. The stability of amorphous Ge2Sb2Te5 thin films subjected to ion irradiation is discussed in terms of the free energy variation of the amorphous state because of damage accumulation. © 2008 Elsevier B.V. Al…
Design of Er3+-doped chalcogenide glass laser for MID-IR application
2009
Abstract The feasibility of a photonic crystal fiber laser (PCF laser), made of a novel Er 3+ -doped chalcogenide glass and operating at the wavelength λ s = 4.5 μm is investigated. The design is performed on the basis of spectroscopic and optical parameters measured on a fabricated Er 3+ -doped Ga 5 Ge 20 Sb 10 S 65 chalcogenide bulk sample. The simulations have been performed by employing a home made numerical code that solves the multilevel rate equations and the power propagation equations via a Runge-Kutta iterative method. The numerical results indicate that a laser exhibiting slope efficiency close to the maximum theoretical one and a wide tunability in the wavelengths range where t…
Small-core chalcogenide microstructured fibers for the infrared.
2008
International audience; We report several small-core chalcogenide microstructured fibers fabricated by the "Stack & Draw" technique from Ge(15)Sb(20)S(65) glass with regular profiles. Mode field diameters and losses have been measured at 1.55 microm. For one of the presented fibers, the pitch is 2.5 microm, three times smaller than that already obtained in our previous work, and the corresponding mode field diameter is now as small as 3.5 microm. This fiber, obtained using a two step "Stack & Draw" technique, is single-mode at 1.55 microm from a practical point of view. We also report the first measurement of the attenuation between 1 and 3.5 microm of a chalcogenide microstructured fiber. …
Chalcogenide Photonic Crystal Fibers for Near and Middle Infrared Applications
2007
Chalcogenide glasses are based on sulphur, selenium, tellurium and the addition of other elements such as arsenic, germanium, antimony, gallium, etc. Chalcogenide fibers present numerous applications in the IR field, such as telecommunication at 1.55 mum, spectroscopy and military systems in the two atmospherics windows (3-5 mum and 8-12 mum). One of the interests of chalcogenide glasses is to associate high non linear properties with their Infrared transmission from 0.51 mum to 12-18 mum depending on the composition. Indeed, chalcogenide glasses present high third order optical properties, 100 - 1000 times as high as the non linearity of silica glass at 1.55 mum. For many applications, sin…