Characterization of a mortar made with cement and sludge from the light-emitting diode manufacturing process

1996 ◽

Author(s):

J. Zimmer ◽

D. Nielsen ◽

T.A. Anderson ◽

M. Schade ◽

N. Saha ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Light Emitting Diode ◽

Elevated Concentration ◽

Forward Voltage ◽

Light Emitting ◽

Intermittent Yield ◽

Si Doped ◽

Secondary Ion ◽

Furnace Pressure

Abstract The p-n junction of a GaAs light emitting diode is fabricated using liquid phase epitaxy (LPE). The junction is grown on a Si doped (~1018/cm3) GaAs substrate. Intermittent yield loss due to forward voltage snapback was observed. Historically, out of specification forward voltage (Vf) parameters have been correlated to abnormalities in the junction formation. Scanning electron (SEM) and optical microscopy of cleaved and stained samples revealed a continuous layer of material approximately 2.5 to 3.0 urn thick at the n-epi/substrate interface. Characterization of a defective wafer via secondary ion mass spectroscopy (SIMS) revealed an elevated concentration of O throughout the region containing the defect. X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES) data taken from a wafer prior to growth of the epi layers did not reveal any unusual oxidation or contamination. Extensive review of the processing data suggested LPE furnace pressure was the obvious source of variability. Processing wafers through the LPE furnace with a slight positive H2 gas pressure has greatly reduced the occurrence of this defect.

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Implantable Optrode Array for Optogenetic Modulation and Electrical Neural Recording

Micromachines ◽

10.3390/mi12060725 ◽

2021 ◽

Vol 12 (6) ◽

pp. 725

Author(s):

Saeyeong Jeon ◽

Youjin Lee ◽

Daeho Ryu ◽

Yoon Kyung Cho ◽

Yena Lee ◽

...

Keyword(s):

Light Emitting Diode ◽

Neural Recording ◽

Electrophysiological Recording ◽

Light Emitting ◽

Technological Advances ◽

Neuroscience Research ◽

Cell Type Specific ◽

Novel Design

During the last decade, optogenetics has become an essential tool for neuroscience research due to its unrivaled feature of cell-type-specific neuromodulation. There have been several technological advances in light delivery devices. Among them, the combination of optogenetics and electrophysiology provides an opportunity for facilitating optogenetic approaches. In this study, a novel design of an optrode array was proposed for realizing optical modulation and electrophysiological recording. A 4 × 4 optrode array and five-channel recording electrodes were assembled as a disposable part, while a reusable part comprised an LED (light-emitting diode) source and a power line. After the characterization of the intensity of the light delivered at the fiber tips, in vivo animal experiment was performed with transgenic mice expressing channelrhodopsin, showing the effectiveness of optical activation and neural recording.

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In-situ characterization of polymer crystallization using a low-cost light emitting diode array as optical receiver with photogain

Proceedings of the 21st IEEE Instrumentation and Measurement Technology Conference (IEEE Cat. No.04CH37510) ◽

10.1109/imtc.2004.1351544 ◽

2004 ◽

Author(s):

F. De Santis ◽

H.C. Neitzert

Keyword(s):

Light Emitting Diode ◽

Low Cost ◽

Polymer Crystallization ◽

Optical Receiver ◽

Diode Array ◽

In Situ Characterization ◽

Light Emitting

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Design, Measurements and Characterization of Smart Electronic Board for PV Streetlight based on LED and High Intensity Discharge Lamps

Advanced Instrument Engineering ◽

10.4018/978-1-4666-4165-5.ch012 ◽

2013 ◽

pp. 153-165

Author(s):

Paolo Visconti ◽

Daniele Romanello ◽

Giovanni Zizzari ◽

Vito Ventura ◽

Giorgio Cavalera

Keyword(s):

Rural Areas ◽

High Intensity ◽

Light Emitting Diode ◽

Light Emitting ◽

Electronic Board ◽

Lighting Systems ◽

And Control ◽

Near Future ◽

Hid Lamps

This work presents an electronic board for driving and control of High Intensity Discharge (HID) lamps and Light Emitting Diode (LED) lamps. The proposed electronic board is able to drive HID or LED lamps by means of a reconfigurable output. This feature allows using the ballast in lighting systems that currently use traditional discharge lamps, as well as keeping the same ballast when discharge lamps are replaced by LED modules in the near future, when LED street lighting systems will be more affordable. Additionally, since the lighting system is designed to be used in rural areas where there is no public electricity, each lighting point incorporates a system to convert solar energy into continuous voltage by means of photovoltaic panels. In this work, energy saving issues are taken into account.

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