Search results for "Optoelectronics"
showing 10 items of 2306 documents
Planar Array Technology for the Fabrication of Germanium X-Ray Microcalorimeters
2008
Several technologies are presently competing for measuring the temperature increase in cryogenic micro-calorimeters used as high resolution energy-dispersive X-ray detectors. Doped germanium, whose resistivity depends on temperature, is a promising material for this purpose, because of its comparatively low specific heat and the possibility of making wafers with high doping uniformity by neutron transmutation. Presently, Ge-based microcalorimeters are still micro-machined and manually assembled. Here we present a planar approach to the fabrication of 2-D arrays of microcalorimeters and show the preliminary technological results.
Self-assembled three-dimensional inverted photonic crystals on a photonic chip
2017
Three dimensional photonic crystals (PhCs) exhibiting a full photonic band gap have high potential in optical signal processing and detector applications. However, the challenges in the integration of the 3D PhCs into photonic circuits have so far hindered their exploitation in real devices. This article demonstrates the fabrication of 3D PhCs exploiting the capillary directed self-assembly (CDSA) of monodisperse colloidal silica spheres, their inversion to silicon shells, and integration with silicon waveguides. The measured transmission characteristics agree with numerical predictions and provide strong indication of a full photonic band gap in the inverted 3D photonic crystals at wavelen…
Crystallization of silica opals onto patterned silicon wafer
2006
We report on fabrication of high quality opaline photonic crystals from large silica spheres, self-assembled in hydrophilic trenches of silicon wafers by using a drawing apparatus with a combination of stirring. The achievements here reported comprise a spatial selectivity of opal crystallization without special treatment of the wafer surface, a filling of the trenches up to the top, leading to a spatially uniform film thickness, particularly an absence of cracks within the size of the trenches, and finally a good three-dimensional order of the opal lattice even in trenches with a complex confined geometry, verified using optical measurements. The opal lattice was found to match the pattern…
Flexible MgO-Based Magnetic Tunnel Junctions on Silicon Substrate
2018
Flexible electronic devices are emerging in many areas, providing novel features and creating new applications [1]. Due to their ubiquitous utilization, flexible magnetic sensors [2] play a critical part in this development. In particular, magnetic tunnel junctions (MTJs) are of great interest, because of advantages like low power consumption or high sensitivity. We report the development of flexible MTJs on a silicon substrate fabricated by a low-cost batch process [3]. Thereby, conventionally fabricated MTJ devices are transformed into flexible ones by thinning down the silicon wafer from 500 μm to 5 μm. This process leads to thin, bendable silicon devices, while maintaining their origina…
Planar Technology for NDT-Ge X-Ray Microcalorimeters: Absorber Fabrication
2009
We have investigated the electroplating process to deposit thick uniform films of tin on a Ge wafer coated with Spin‐On Glass, in order to fabricate the absorbers for Ge microcalorimeter arrays. Here we discuss some technological details and propose two alternative metal bilayer to be used as seed for the electroplating.
Light-Induced Sublimation of Cadmium Sulphide
1984
It has recently been shown that single crystal CdS, illuminated by light whose photon energy exceeds the bandgap, can eject particles from its surface while the temperature is well below the value required for vacuum sublimation. This phenomenon has obvious applications to the fabrication of surface structures as well as to the production of thin films that can show good CdS stoichiometry. This work will present several data on the morphology of the etched surface and its dependance on crystal orientation; results of an analysis of the recondensed thin film phase from the ejected material will also be shown. Emphasis will be devoted to examples of high resolution surface structures fabricat…
Technologies for the fabrication of cylindrical fine line devices
1997
Abstract A microlithographic process suited for metal patterning on cylindrical substrates has been developed. This includes all steps from metal coating to final etching, with resolution in the 5 μm range.
TiO2 in memristors and resistive random access memory devices
2021
Abstract One of the most recent applications of TiO2 thin films is as an oxide layer in memristors, electronic devices considered as one of the most promising nonvolatile memories and as possible building units for neuromorphic computing. This chapter aims to describe several fabrication ways, either (electro)chemical or physical methods, of TiO2 thin films and to highlight the relationship between method and layer properties. Some fundamentals on the mechanism of memristors’ operation, that is, resistive switching in oxide thin films, will be given, classifying the different types of devices based on the used electrode materials and underlying physicochemical processes. Finally, it will be…
Thin Film Metal Oxides for Displays and Other Optoelectronic Applications
2020
Thin films of metal oxides have been extensively studied for various applications because of their durability, lower cost and lower toxicity, excellent chemical, magnetic, electrical and optical properties. A fusion of electrical and optical properties led to the growth of optoelectronic devices for a variety of applications including displays, light-emitting diodes, photovoltaic cells, photodetectors, optical storage, medicine, and so on. Optoelectronic devices have revolutionized our daily lives with their potentials in various aspects. An extensive research on materials for these devices has to be credited for the improvement in their performance over the years. Several metal oxide thin …
Single Photon Emission from Site-Controlled InAs Quantum Dots Grown on GaAs(001) Patterned Substrates
2009
5 páginas, 5 figuras.