A visualization of threading dislocations formation and dynamics in mosaic growth of GaN-based light emitting diode epitaxial layers on (0001) sapphire

2012 ◽  
Vol 101 (23) ◽  
pp. 231911 ◽  
Author(s):  
P. Ravadgar ◽  
R. H. Horng ◽  
S. L. Ou
Keyword(s):  
Light Emitting Diode ◽  
Epitaxial Layers ◽  
Threading Dislocations ◽  
Light Emitting

ToF-SIMS, Time-of-Flight Secondary Ion Mass Spectroscopy for Counterfeit Detection of Electrical, Electronic, and Electromechanical (EEE) Parts

2019 ◽  
Author(s):  
M. Simard-Normandin ◽  
C. Banks ◽  
N. Havercroft ◽  
P. Clark ◽  
E. Tallarek
Keyword(s):  
Mass Spectroscopy ◽  
Light Emitting Diode ◽  
Semiconductor Devices ◽  
Time Of Flight ◽  
Epitaxial Layers ◽  
Secondary Ion Mass Spectroscopy ◽  
Light Emitting ◽  
Led Light ◽  
Tof Sims ◽  
Secondary Ion

Abstract This presentation demonstrates how Time-of-Flight Secondary Ion Mass Spectroscopy provides unique information to identify suspect counterfeit semiconductor devices. An example is shown where the epitaxial layers of a light emitting device (LED) do not match those of the exemplar. Keywords: Secondary Ion Mass Spectroscopy, SIMS, counterfeit detection, LED, Light emitting diode.

Synchronization of Chaotic Quantum Dot Light Emitting Diodes under Optical Feedback Effect

2020 ◽  
pp. 144-148
Keyword(s):  
Quantum Dot ◽  
Delay Time ◽  
Chaos Synchronization ◽  
Optical Feedback ◽  
Light Emitting Diode ◽  
Feedback Effect ◽  
Complete Synchronization ◽  
Light Emitting ◽  
Coupling Methods ◽  
Coupling Parameters

Chaos synchronization of delayed quantum dot light emitting diode has been studied theortetically which are coupled via the unidirectional and bidirectional. at synchronization of chaotic, The dynamics is identical with delayed optical feedback for those coupling methods. Depending on the coupling parameters and delay time the system exhibits complete synchronization, . Under proper conditions, the receiver quantum dot light emitting diode can be satisfactorily synchronized with the transmitter quantum dot light emitting diode due to the optical feedback effect.

Effects of Nitridation Time on Top-emission Inverted Organic Light Emitting Diode

PIERS Online ◽  
2007 ◽  
Vol 3 (6) ◽  
pp. 821-824 ◽  
Author(s):  
Chien-Chang Tseng ◽  
Liang-Wen Ji ◽  
Yu Sheng Tsai ◽  
Fuh-Shyang Juang
Keyword(s):  
Light Emitting Diode ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Nitridation Time ◽  
Organic Light

Items Searching in Factory Warehouse Using Arduino Module

2019 ◽  
Vol 1 (1) ◽  
pp. 1-14
Author(s):  
Tan Liong Ching ◽  
Nureize Binti Arbaiy
Keyword(s):  
Inventory Management ◽  
Liquid Crystal Display ◽  
Light Emitting Diode ◽  
Storage System ◽  
Voice Recognition ◽  
Inventory System ◽  
Search Process ◽  
Light Emitting ◽  
Recognition Function ◽  
Light Function

The smart store system (F3 Storage System) provides an inventory system function, and is supported by voice recognition for items searching purpose in the warehouse. This system is aimed to improve effectiveness in item searching process for the warehouse management. An inventory system structures is employed in this system to enable items management. Voice recognition facility helps the worker to search item in an effective way. Worker can use voice recognition function to search the item in the warehouse, and searched information of the item will be displayed in the liquid crystal display (LCD) screen. Meanwhile, the location of the item will be physically indicated by the light emitting diode (LED) light function. The developed system also contains a barcode system to enhance the process of scheduling warehouse activity. Such facilities will enhance the capabilities of existing inventory management systems in warehouses. Prototyping model is used to assist project development. Arduino technology is used to enable integrated hardware and software to read data or input. With Arduino technology, traditional search items by using text and search functionality are enhanced to allow speech functionality. This functionality makes the search process faster and more efficient.

Temperature and Humidity Dependent Reliability Analysis of RGB LED Chips

2006 ◽  
Author(s):  
Jun-Xian Fu ◽  
Shukri Souri ◽  
James S. Harris
Keyword(s):  
Reliability Analysis ◽  
Printed Circuit Board ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Light Emitting ◽  
Printed Circuit ◽  
Root Cause ◽  
Micro Cracks ◽  
Temperature And Humidity

Abstract Temperature and humidity dependent reliability analysis was performed based on a case study involving an indicator printed-circuit board with surface-mounted multiple-die red, green and blue light-emitting diode chips. Reported intermittent failures were investigated and the root cause was attributed to a non-optimized reflow process that resulted in micro-cracks and delaminations within the molding resin of the chips.

Characterization and Elimination of Forward Snapback Defects in GaAs Light Emitting Diodes

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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