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Enhancing Performance of Ce:YAG Luminescent Concentrators for High Power Applications
2019 Edition, June 1, 2019 - IEEE - Institute of Electrical and Electronics Engineers, Inc.

High power scaling of an LED pumped luminescent concentrator (LC) can address significant excitation and illumination applications, including laser pumping and medical light therapy [1-3]. However, heat deposited into the luminescent material is critical and was already...

High power LEDs for solid state lighting
2010 Edition, September 1, 2010 - IEEE - Institute of Electrical and Electronics Engineers, Inc.

For solid stated lighting high light output in combination with high conversion efficacy is essential. High efficiencies are relatively easy to realize at low current densities, but efficiency tends to decline as the current is cranked up. In order to overcome the barriers for...

Tunnel junction devices with monolithic optically pumped and electrically injected InGaN quantum wells for polarized white light emission
2016 Edition, June 1, 2016 - IEEE - Institute of Electrical and Electronics Engineers, Inc.

Summary form only given. We demonstrate polarized white light emission from a semipolar device in which a tunnel junction is used to monolithically integrate a blue electrically injected light-emitting diode (LED) and yellow-emitting InGaN quantum wells (QWs) that are optically pumped...

Towards high reliability GaN LEDs: Understanding the physical origin of gradual and catastrophic failure
2015 Edition, November 1, 2015 - IEEE - Institute of Electrical and Electronics Engineers, Inc.

This paper reviews the most relevant mechanisms responsible for the gradual and catastrophic failure of InGaN-based light emitting diodes, for application in general lighting. Based on recent results obtained on state-of-the-art LEDs and lamps, we discuss the following: (i) the...

High-Efficiency and Crack-Free InGaN-Based LEDs on a 6-inch Si (111) Substrate With a Composite Buffer Layer Structure and Quaternary Superlattices Electron-Blocking Layers
2014 Edition, Volume 50, May 1, 2014 - IEEE - Institute of Electrical and Electronics Engineers, Inc.

In this paper, a composite buffer layer structure (CBLS) with multiple AlGaN layers and grading of Al composition/u-GaN1/(AlN/GaN) superlattices/u-GaN2 and InAlGaN/AlGaN quaternary superlattices electron-blocking layers (QSLs-EBLs) are introduced into the epitaxial growth of InGaN-based...

Advantages of InGaN Light Emitting Diodes With Alternating Quantum Barriers
2015 Edition, Volume 11, May 1, 2015 - IEEE - Institute of Electrical and Electronics Engineers, Inc.

InGaN light-emitting diodes (LEDs) with the alternating quantum barriers (AQB) of AlGaN and InGaN is proposed for LED applications. With this design, simulation results show that the carrier concentration and transport in the multi-quantum well (MQW) active region...

Phase separation in bulk InGaN and quantum wells grown by low pressure MOCVD
1997 Edition, January 1, 1997 - IEEE - Institute of Electrical and Electronics Engineers, Inc.

We have grown high quality InGaN layers and InGaN/GaN multiple quantum wells for blue LED applications. The degree of phase segregation of InGaN in bulk InGaN layers depends on the TMI and TMG flow rates as well as the growth temperature. Even for...

High-temperature nanophosphors for white-light-emitting diodes
2011 Edition, July 1, 2011 - IEEE - Institute of Electrical and Electronics Engineers, Inc.

Single chip white-LEDs are necessary in future optimal lighting applications for daylight quality lighting and energy efficiency. InGaN/GaN-based blue LEDs with nanophosphors encapsulated in silicone can effectively render daylight quality illumination.

Efficiency Droop Reduction in InGaN LEDs by Alternating AlGaN Barriers With GaN Barriers
2015 Edition, Volume 27, April 15, 2015 - IEEE - Institute of Electrical and Electronics Engineers, Inc.

In InGaN-based light-emitting diodes (LEDs), some specific designs on the quantum barrier layers by alternating AlGaN barriers with GaN barriers are proposed. Compared with the original structures with GaN barriers or AlGaN barriers, the proposed structure shows significant...

Process Integration and Interconnection Design of Passive-Matrix LED Micro-Displays with 256 Pixel-Per-Inch Resolution
Volume PP - IEEE - Institute of Electrical and Electronics Engineers, Inc.

A 0.28-inch InGaN-based blue micro-LED display with 256 pixel-per-inch resolution and a pitch of 100 μm was successfully fabricated in this study. A thick Ti/Al/Ti/Au interconnection metal was deposited on the n-type gallium nitride (n-GaN) region to reduce the interconnection...

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