Search results for "electronics"
showing 10 items of 4340 documents
Epitaxial Thin-Film vs Single Crystal Growth of 2D Hofmann-Type Iron(II) Materials: A Comparative Assessment of their Bi-Stable Spin Crossover Proper…
2020
Integration of the ON-OFF cooperative spin crossover (SCO) properties of FeII coordination polymers as components of electronic and/or spintronic devices is currently an area of great interest for potential applications. This requires the selection and growth of thin films of the appropriate material onto selected substrates. In this context, two new series of cooperative SCO two-dimensional FeII coordination polymers of the Hofmann-type formulated {FeII(Pym)2[MII(CN)4]·xH2O}n and {FeII(Isoq)2[MII(CN)4]}n (Pym = pyrimidine, Isoq = isoquinoline; MII = Ni, Pd, Pt) have been synthesized, characterized, and the corresponding Pt derivatives selected for fabrication of thin films by liquid-phase …
Raman-assisted parametric frequency conversion in a normally dispersive single-mode fiber
1999
International audience; We demonstrate efficient frequency conversion with large frequency shifts of an anti-Stokes signal into a parametrically seeded Stokes idler, which is generated by a highly mismatched three-wave mixing interaction and subsequent Raman amplification in a normally dispersive single-mode fiber. The use of non-phase-matched waves in Raman-assisted three-wave mixing interactions overcomes the strict spectral limitations imposed by phase-matching conditions in parametric frequency-conversion processes.
Electrochemical Tantalum Oxide for Resistive Switching Memories
2017
Redox-based resistive switching memories (ReRAMs) are strongest candidates for the next-generation nonvolatile memories fulfilling the criteria for fast, energy efficient, and scalable green IT. These types of devices can also be used for selector elements, alternative logic circuits and computing, and memristive and neuromorphic operations. ReRAMs are composed of metal/solid electrolyte/metal junctions in which the solid electrolyte is typically a metal oxide or multilayer oxides structures. Here, this study offers an effective and cheap electrochemical approach to fabricate Ta/Ta2O5-based devices by anodizing. This method allows to grow high-quality and dense oxide thin films onto a metal…
Luminescence of phosphorus doped silica glass
2017
This work is supported by Material Science program IMIS2 of Latvia.
Energy scales and dynamics of electronic excitations in functionalized gold nanoparticles measured at the single particle level.
2019
The knowledge of the electronic structure and dynamics of nanoparticles is a prerequisite to develop miniaturized single-electron devices based on nanoparticles. Low-temperature transport measurements of individual stable metallic nanoparticles enable unravelling the system specific electronic structure while ultrafast optical spectroscopy gives access to the electron dynamics. In this work, we investigate bare and thiol-functionalized gold nanoparticles. For the latter, we employ a fast and low-cost fabrication technique which yields nanoparticles with narrow size distribution. Using relatively long thiol-ended alkane chains for the functionalization modifies the electronic density of stat…
Pyranylidene indene-1,3-dione derivatives as an amorphous red electroluminescence material
2011
The organic light-emitting diode (OLED) has promising applications in flat-panel displays and novel light sources. Thus far, OLED structures have mostly been made by thermal evaporation in vacuum. An alternative approach is to use small molecules that form amorphous (glassy) structures from solutions. Such compounds can be used in ink-jet printing technologies and result in reduced OLED prices. We present an original red fluorescent organic compo- und 2-(2-(4-(bis(2-(trityloxy)ethyl)amino)styryl)-6-methyl-4H-pyran-4-ylidene)-1H-indene-1, 3(2H)-dione (ZWK1), and its derivative 2-(2,6-bis(4-(bis(2-(trityloxy)ethyl) amino)styryl)-4H- pyran-4-ylidene)-1H-indene-1,3(2H)-dione (ZWK2), where the m…
Low Current Density Driving Leads to Efficient, Bright and Stable Green Electroluminescence
2013
Electroluminescent devices have the potential to reshape lighting and display technologies by providing low-energy consuming solutions with great aesthetic features, such as flexibility and transparency. In particular, light-emitting electrochemical cells (LECs) are among the simplest electro-luminescent devices. The device operates with air-stable materials and the active layer can be resumed to an ionic phosphorescent emitter. As a consequence, LECs can be assembled using solution-process technologies, which could allow for low-cost and large-area lighting applications in the future. High efficiencies have been reported at rather low luminances (<50 cd m(-2)) and at very low current densi…
Vacuum-Deposited 2D/3D Perovskite Heterojunctions
2019
Low-dimensional (quasi-) 2D perovskites are being extensively studied in order to enhance the stability and the open-circuit voltage of perovskite solar cells. Up to now, thin 2D perovskite layers on the surface and/or at the grain boundaries of 3D perovskites have been deposited solely by solution processing, leading to unavoidable intermixing between the two phases. In this work, we report the fabrication of 2D/3D/2D perovskite heterostructures by dual-source vacuum deposition, with the aim of studying the interaction between the 3D and 2D phases as well as the charge transport properties of 2D perovskites in neat 2D/3D interfaces. Unlike what is normally observed in solution-processed 3D…
High efficiency single-junction semitransparent perovskite solar cells
2014
Semitransparent perovskite solar cells with a high power conversion efficiency (PCE) above 6% and 30% full device transparency have been achieved by implementing a thin perovskite layer and a simple foil compatible layout.
Memory effects in MOS capacitors with silicon quantum dots
2001
To form crystalline Si dots embedded in SiO2, we have deposited thin films of silicon-rich oxide (SRO) by plasma-enhanced chemical vapor deposition of SiH4 and O2. Then the materials have been annealed in N2 ambient at temperatures between 950°C and 1100°C. Under such processing, the supersaturation of Si in the amorphous SRO film produces the formation of crystalline Si dots embedded in SiO2. The narrow dot size distributions, analyzed by transmission electron microscopy, are characterized by average grain radii and standard deviations down to about 1 nm. The memory functions of such structures has been investigated in MOS capacitors with a SRO film sandwiched between two thin SiO2 layers …