• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer

Electrical Engineering News and Products

Electronics Engineering Resources, Articles, Forums, Tear Down Videos and Technical Electronics How-To's

  • Products / Components
    • Analog ICs
    • Connectors
    • Microcontrollers
    • Power Electronics
    • Sensors
    • Test and Measurement
    • Wire / Cable
  • Applications
    • Automotive
    • Industrial
    • IoT
    • Medical
    • Telecommunications
    • Wearables
    • Wireless
  • Resources
    • Covid-19
    • DesignFast
    • Ebooks / Tech Tips
    • EE Forums
      • EDABoard.com
      • Electro-Tech-Online.com
    • FAQs
    • 2020 LEAP Awards
    • Oscilloscope Product Finder
    • Podcasts
    • Webinars
    • White Papers
  • Videos
    • Teardown Videos
  • Lee’s Teardowns
    • Teardown Videos
  • Learning Center
  • 5G
  • Women in Engineering

Better Materials Promise LED’s At A Fraction Of The Cost

December 11, 2015 By Aalto University

For the reactors used in the manufacture of LED’s there are more promising materials than the ones currently in use, the researchers point out.

There are many new possibilities for the development of gallium nitride (GaN) used in the production LEDs. One of the most promising production methods of gallium nitride is the ammonothermal method which uses a reactor filled up with liquid ammonia. The method is identical with the hydrothermal method utilised in the production of quartz, in which water is used instead of ammonia.

However, the high temperature inside the ammonothermal reactor combined with a pressure 2,500 times the atmospheric pressure and the corrosive effects of the so-called supercritical fluid pose a challenge to the reactor chamber and thus to the manufacture of LED materials. To find a solution to the problem, Aalto University Post-Doctoral Researcher Sami Suihkonen and a research group from the University of California, Santa Barbara led by Nobelist in Physics Shuji Nakamura and Post-Doctoral Researcher Siddha Pimputkar systematically analysed the behaviours of 35 metals, 2 metalloids and 17 different ceramic materials with 3 different supercritical fluid chemistries heated to a temperature of 572 degrees Celsius.

“In the ammonothermal method, the energy contained in the reactor corresponds roughly to a stick of dynamite, making the conditions fairly hostile,” saysSami Suihkonen.

“A nickel-chromium alloy commonly used in the reactors tolerates ordinary supercritical ammonia quite well but poorly withstands the effects of the mixtures used in the production of GaN which include the addition of ammonium chloride or sodium. Our research indicated that vanadium, niobium and tungsten carbide are stable in all three supercritical fluids. For practical applications, however, it is more important to find a material best suited for a certain type of chemistry. For ammonium-sodium this was silver; with ammonium-chloride, silicon nitride and noble metals appear the most promising.”

Higher quality materials with applications in power electronics

To replace the reactor’s nickel-chromium alloy with other structural materials would require the reshaping of the manufacturing process according to Suihkonen. More robust reactors would nevertheless enable the production of higher quality GaN containing fewer crystal defects which in turn leads to higher quality LEDs. Better LED quality translates to cheaper price.

“From a high-quality LED more light can be obtained per surface-area unit. As the price of an LED is governed by its surface area, better materials could reduce the price of LEDs to even a fraction of the current price Suihkonen calculates. Moreover, higher quality LED’s generate less heat and thus require smaller cooling elements, which could further reduce the price and enable LED lighting fixtures that are more compact than the current ones.”

Apart from their use in more economical and efficient illumination, these better materials could be useful also in power electronics, which is needed among other things, in power control of electric vehicles, in power supplies and converters.

The Stability of Materials in Supercritical Ammonia Solutions study was recently published in the Journal of Supercritical Fluids.

Filed Under: Displays

Primary Sidebar

EE Training Center Classrooms

“ee

“ee

“ee

“ee

Featured Resources

  • NEW! EE World Online Learning Center
  • CUI Devices – CUI Insights Blog
  • EE Classroom: Power Delivery
  • EE Classroom: Building Automation
  • EE Classroom: Aerospace & Defense
  • EE Classroom: Grid Infrastructure

Autonomous & Connected Vehicles 2019


RSS Current EDABoard.com discussions

  • Advantages of not instantiating DPRAM but to realize by registers
  • How to compare Matlab/Theory <=> Cadence: Switched-cap. Integrator: Mag & Phase
  • SI and SE of double stage synchoronizer
  • Can i use pic mcu as switch on dc-dc step up?
  • smps

RSS Current Electro-Tech-Online.com Discussions

  • NE555p circuit help
  • new to Ardunio but trying to compile
  • Primary FET heatsink connected to earth in offline flyback?
  • Accumulator?
  • Creepage distances for offline SMPS

Oscilloscopes Product Finder

Follow EE World on Twitter

Tweets by @EEWorldOnline

Footer

EE World Online

EE WORLD ONLINE NETWORK

  • DesignFast
  • EDABoard Forums
  • Electro-Tech-Online Forums
  • Microcontroller Tips
  • Analog IC Tips
  • Connector Tips
  • Engineer's Garage
  • Power Electronic Tips
  • Sensor Tips
  • Test and Measurement Tips
  • Wire & Cable Tips
  • 5G Technology World

EE WORLD ONLINE

  • Subscribe to our newsletter
  • Lee's teardown videos
  • Advertise with us
  • Contact us
  • About Us
Follow us on TwitterAdd us on FacebookFollow us on YouTube Add us on Instagram

Copyright © 2021 · WTWH Media LLC and its licensors. All rights reserved.
The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media.

Privacy Policy