Search results for "electronics"

Emission Electron Microscopy of Nanoparticles in Strong fs Laser Fields

2003

Heteroepitaxial growth of Co on W(110) investigated by scanning tunneling microscopy

2003

We investigated the growth of Co submonolayers on bcc W(110) by scanning tunneling microscopy. Due to the strong Co-W bonding, monolayers of Co grow in equilibrium pseudomorphically on W(110) until the monolayer is almost completed. When excess atoms are deposited atop the pseudomorphic monolayer, it transforms to a close-packed (cp) monolayer with misfit dislocation lines parallel to $[11\ifmmode\bar\else\textasciimacron\fi{}0]$ (Nishiyama-Wassermann orientation). The structure of the cp monolayer, as concluded from atomically resolved STM images, deviates from the rigid hard-sphere model of a cp (111) layer. Details of the structure are compared to a structure model previously proposed by…

Vacuum-Deposited Microcavity Perovskite Photovoltaic Devices

2021

The interaction between semiconductor materials and electromagnetic fields resonating in microcavities or the light-matter coupling is of both fundamental and practical significance for improving the performance of various photonic technologies. The demonstration of light-matter coupling effects in the emerging perovskite-based optoelectronic devices via optical pumping and electrical readout (e.g., photovoltaics) and vice versa (e.g., light-emitting diodes), however, is still scarce. Here, we demonstrate the microcavity formation in vacuum-deposited methylammonium lead iodide (CH3NH3PbI3, MAPI) p-i-n photovoltaic devices fabricated between two reflecting silver electrodes. We tune the posi…

Phase defect inspection of multilayer masks for 13.5 nm optical lithography using PEEM in a standing wave mode

2007

We report on recent developments of an "at wavelength" full-field imaging technique for defect inspection of multilayer mask blanks for extreme ultraviolet lithography (EUVL). Our approach uses photoemission electron microscopy (PEEM) in a near normal incidence mode at 13.5 nut wavelength to image the photoemission induced by the EUV wave field on the multilayer blank surface. We analyze buried defects on Mo/Si multilayer samples down to a lateral size of 50 nm and report on first, results obtained from a six inches mask blank prototype as prerequisite for industrial usage. (c) 2007 Elsevier B.V. All rights reserved.

Optimizing geometry of low-Q all-metal Fabry-Pérot microcavity for fluorescence spectroscopy

2021

Abstract Fluorescence spectroscopy is commonly employed to study the excited-state photophysics of organic molecules. Planar Fabry-Pérot microcavities play an essential role in such studies and a strategic cavity design is necessary to attain an enhanced light-matter interaction. In this work, we computationally study different geometries for a planar metallic Fabry-Pérot microcavity tuned for the absorption of Sulforhodamine 101, a typical dye for fluorescence spectroscopy. The cavity consists of a polymer layer enclosed between two silver mirrors, where the thicknesses of all the three layers are varied to optimize the cavity. Our transfer-matrix and finite-difference time-domain simulati…

Whispering gallery mode resonators coated with Au nanoparticles

2019

Whispering gallery mode resonators (WGMRs) are very interesting for sensing because a resonance shift could be caused by any perturbation of the surrounding environment. Additionally such a resonator is coated with nanomaterials to tailor and enhance the sensitivity for a specific purpose. WGMR were fabricated using standard telecommunication fiber and a hydrogen flame, characterized using the scan method to obtain the quality factors and then coated with gold nanoparticles (Au NPs) using dip coating method and characterized again for comparison. Au NPs were chosen because their positive impact on microresonator sensitivity has been mentioned before and the surface can later be functionaliz…

The structure of PLZT ceramics and holographic recording

1992

Abstract The influence of the specific structure of transparent PLZT X/65/35 [Pb1-xLax (Zr.65Ti.35)1-x/4O3] ceramics with x = 8.5% and IO% on photorefraction and peculiarities of holographic recording have been studied.

Modulation of coaxial modal interferometers based on long period gratings in double cladding fibers

2009

This paper reports on the dynamic modulation of coaxial interferometers based on two cascaded long period gratings written in double cladding fibers. The interferometer is modulated by a piezoelectric ceramic which stretches one the gratings at tens of kHz, the output light is intensity modulated with an efficiency of 97 %. The device operates at 1530nm, has more than 50nm bandwidth, insertion loss of 0.4 dB and a temperature drift of 0.11 nm/ degrees C.

Digital video-electrochemistry (DVEC) to assess electrochromic materials in the frequency domain: RGB colorimetry impedance spectroscopy

2021

Abstract This work is the first one allowing the characterization of electrochromic devices simultaneously at various parts on their surface and different rates of color change. We describe a new proficient and affordable methodology for reporting electrochromic parameters such as coloration efficiency, optical contrast, and switching time based on the use of digital video-electrochemistry (DVEC) in the ac regime, namely RGB colorimetry impedance spectroscopy. Simultaneously with the electrochemical impedance spectroscopy, the RGB color changes of an electrochromic electrode were recorded by a CCD digital camera at 120 digital images per second. In such conditions, RGB electrochromic change…

Micro-photoluminescence of Carbon Dots Deposited on Twisted Double-Layer Graphene Grown by Chemical Vapor Deposition

2021

Carbon-based nanomaterials, such as carbon dots (CDs) and graphene (Gr), feature outstanding optical and electronic properties. Hence, their integration in optoelectronic and photonic devices is easier thanks to their low dimensionality and offers the possibility to reach high-quality performances. In this context, the combination of CDs and Gr into new nanocomposite materials CDs/Gr can further improve their optoelectronic properties and eventually create new ones, paving the way for the development of advanced carbon nanotechnology. In this work, we have thoroughly investigated the structural and emission properties of CDs deposited on single-layer and bilayer graphene lying on a SiO2/Si …