Group III-Nitride Based Electronic and Optoelectronic Integrated Circuits for Smart Lighting Applications

2013 ◽  
Vol 1492 ◽  
pp. 123-128 ◽  
Author(s):  
J. Justice ◽  
A. Kadiyala ◽  
J. Dawson ◽  
D. Korakakis

ABSTRACTWith general lighting applications being responsible for over 20% of the energy consumption in the United States, advances in solid-state lighting have the potential for considerable energy and cost savings. The United States Department of Energy predicts that the increased use of solid state lighting will result in a 46% lighting consumption energy savings by the year 2030. Smart lighting systems have the potential for reducing energy costs while also providing a means for short distance data transmission via free space optics. The group III-nitride (III-N) family of materials, including aluminum nitride (AlN), gallium nitride (GaN), indium nitride (InN), their binary and ternary alloys, are uniquely situated to provide light emitting diodes (LEDs) across the full visible spectrum, photodetectors (PDs) and high power, high speed transistors. In this work, aluminum gallium nitride (AlGaN) / GaN high electron mobility transistors (HEMTs) and indium gallium nitride (InGaN) photodiodes (PDs) are fabricated and characterized. HEMTs and LEDs (or PDs) are grown on the same substrate for the purpose of creating electronic and optoelectronic integrated circuits.

2006 ◽  
Author(s):  
George T Wang ◽  
James Randall Creighton ◽  
Albert Alec Talin

Subject China's options for retaliating against US firms during trade tensions. Significance US President Donald Trump tweeted yesterday that he is working with China's President Xi Jinping to get China's telecoms giant, ZTE, "back in business, fast" -- even though it was penal US sanctions that forced the company to announce last week that it was stopping operations. The Trump administration is divided on whether its objective in threatening imports tariffs on Chinese goods worth 50 billion dollars, effective May 22, is to strike a deal to cut China's trade surplus with the United States or to change China's industrial practices. Impacts Compliance costs will rise even if trade tensions subside. Investors in industries that China sees as strategic (eg, semiconductors and integrated circuits) may face unwritten screening rules. Investors in automobile, aircraft and shipping manufacturing and finance may find new opportunities to enter the market.


2019 ◽  
Vol 9 (1) ◽  
pp. 015011 ◽  
Author(s):  
Ravinder Kour ◽  
Sandeep Arya ◽  
Sonali Verma ◽  
Anoop Singh ◽  
Prerna Mahajan ◽  
...  

Author(s):  
Zonghui Su ◽  
Jonathan A. Malen ◽  
Jacob H. Melby ◽  
Robert F. Davis

Over 20% of electricity in US is used by lighting. Solid state lighting (SSL) efficiency can theoretically surpass that of incandescent and fluorescent lighting techniques. Nonetheless SSL efficiency is greatly reduced at high temperatures that result from inadequate heat dissipation. SSL requires blue and green light emitting diodes (LEDs) made from Gallium Nitride (GaN) and Indium Gallium Nitride (InGaN) to eventually generate white light. Using an infrared thermal imaging camera, temperatures of working blue and green LEDs with different efficiencies were measured. The results show that higher efficiency LEDs have lower active region temperatures when driven with the same power. Further, they motivate our study of thermal properties of the individual thin films that compose the LEDs, since earlier studies show that conduction is the primary dissipative mechanism for heat in LEDs. Bulk thermal properties are poor estimates of thin film properties due to increased boundary and defect scattering of phonons in the films. By examining real LED structures with the 3-omega technique, thin film thermal conductivities can be measured. For this technique, a thin metal line was fabricated onto a smooth dielectric sample surface. This thin metal line works as both a heater and a thermometer. Benchmark studies on Pyrex 7740 were used to validate our 3-omega setup. Data from real GaN/InGaN LED structures show that the effective thermal conductivities of the AlN buffer layer and multi-quantum-well active region are substantially suppressed relative to their anticipated values based on bulk properties.


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