Nav: Home

Energy-saving new LED phosphor

April 24, 2019

Light emitting diodes or LEDs are only able to produce light of a certain colour. However, white light can be created using different colour mixing processes. "In a white LED, red and yellow-green phosphors are excited by the light from a blue diode. The particles emit light in the red and green range, and in combination with the blue light they produce white light," describes Hubert Huppertz from the Department of General, Inorganic and Theoretical Chemistry at the University of Innsbruck, Austria. He and his team are working on improving the red and green phosphors. In cooperation with OSRAM Opto Semiconductors, his team has now succeeded in synthesizing a new red phosphor that has excellent luminescence properties and can make LED lighting significantly more energy-efficient.

Color shift improves luminous efficacy

The powerful red phosphor Sr[Li2Al2O2N2]:Eu2+, named SALON by the researchers, meets all the requirements for the optical properties of a phosphor. The development goes back to research carried out by Hubert Huppertz at the University of Bayreuth. As part of his doctoral thesis, he developed nitrides doped with europium that are fluorescent. These were then further optimised by the working group in Munich and are now widely used. These red phosphors are partly responsible for the fact that LEDs no longer only glow cold white, but also warm white. Interestingly, the human eye reacts most sensitively to the colour green. In the blue and red areas, the eye is less sensitive. Although these phosphors emit red light in the visible range, a large part of the energy goes into the infrared range, which the human eye does not perceive. The fluorescent material developed in Innsbruck has now succeeded in slightly shifting the light emission from red towards blue.

"Since initially only a few very small particles were available in a very inhomogeneous sample, it was difficult to optimise the synthesis," said doctoral student Gregor Hoerder. The breakthrough came when the researchers were able to isolate a single-crystal from one of the most promising synthesis products and thus determine the structure of the new material. "The substance is synthesised in such a way that it emits more orange than red," says Hubert Huppertz. "With SALON we have less energy loss, it emits exactly in the red range we can see."

OSRAM Opto Semiconductors, a strong industrial partner, the Fraunhofer Institute for Microstructures of Materials and Systems IMWS in Halle and Dirk Johrendt's research group at the Ludwig Maximilian University in Munich were also involved in further characterizing the new material. The development has already been registered for patent.
-end-


University of Innsbruck

Related Energy Articles:

Mandatory building energy audits alone do not overcome barriers to energy efficiency
A pioneering law may be insufficient to incentivize significant energy use reductions in residential and office buildings, a new study finds.
Scientists: Estonia has the most energy efficient new nearly zero energy buildings
A recent study carried out by an international group of building scientists showed that Estonia is among the countries with the most energy efficient buildings in Europe.
Mapping the energy transport mechanism of chalcogenide perovskite for solar energy use
Researchers from Lehigh University have, for the first time, revealed first-hand knowledge about the fundamental energy carrier properties of chalcogenide perovskite CaZrSe3, important for potential solar energy use.
Harvesting energy from walking human body Lightweight smart materials-based energy harvester develop
A research team led by Professor Wei-Hsin Liao from the Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong (CUHK) has developed a lightweight smart materials-based energy harvester for scavenging energy from human motion, generating inexhaustible and sustainable power supply just from walking.
How much energy do we really need?
Two fundamental goals of humanity are to eradicate poverty and reduce climate change, and it is critical that the world knows whether achieving these goals will involve trade-offs.
New discipline proposed: Macro-energy systems -- the science of the energy transition
In a perspective published in Joule on Aug. 14, a group of researchers led by Stanford University propose a new academic discipline, 'macro-energy systems,' as the science of the energy transition.
How much energy storage costs must fall to reach renewable energy's full potential
The cost of energy storage will be critical in determining how much renewable energy can contribute to the decarbonization of electricity.
Energy from seawater
A new battery made from affordable and durable materials generates energy from places where salt and fresh waters mingle.
Shifts to renewable energy can drive up energy poverty, PSU study finds
Efforts to shift away from fossil fuels and replace oil and coal with renewable energy sources can help reduce carbon emissions but do so at the expense of increased inequality, according to a new Portland State University study
Putting that free energy around you to good use with minuscule energy harvesters
Scientists at Tokyo Tech developed a micro-electromechanical energy harvester that allows for more flexibility in design, which is crucial for future IoT applications.
More Energy News and Energy Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Teaching For Better Humans 2.0
More than test scores or good grades–what do kids need for the future? This hour, TED speakers explore how to help children grow into better humans, both during and after this time of crisis. Guests include educators Richard Culatta and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Dispatch 3: Shared Immunity
More than a million people have caught Covid-19, and tens of thousands have died. But thousands more have survived and recovered. A week or so ago (aka, what feels like ten years in corona time) producer Molly Webster learned that many of those survivors possess a kind of superpower: antibodies trained to fight the virus. Not only that, they might be able to pass this power on to the people who are sick with corona, and still in the fight. Today we have the story of an experimental treatment that's popping up all over the country: convalescent plasma transfusion, a century-old procedure that some say may become one of our best weapons against this devastating, new disease.   If you have recovered from Covid-19 and want to donate plasma, national and local donation registries are gearing up to collect blood.  To sign up with the American Red Cross, a national organization that works in local communities, head here.  To find out more about the The National COVID-19 Convalescent Plasma Project, which we spoke about in our episode, including information on clinical trials or plasma donation projects in your community, go here.  And if you are in the greater New York City area, and want to donate convalescent plasma, head over to the New York Blood Center to sign up. Or, register with specific NYC hospitals here.   If you are sick with Covid-19, and are interested in participating in a clinical trial, or are looking for a plasma donor match, check in with your local hospital, university, or blood center for more; you can also find more information on trials at The National COVID-19 Convalescent Plasma Project. And lastly, Tatiana Prowell's tweet that tipped us off is here. This episode was reported by Molly Webster and produced by Pat Walters. Special thanks to Drs. Evan Bloch and Tim Byun, as well as the Albert Einstein College of Medicine.  Support Radiolab today at Radiolab.org/donate.