Lowering the cost and environmental footprint of white LEDs

August 31, 2016, American Chemical Society

Replacing traditional light bulbs with light-emitting diodes (LEDs) could take a significant bite out of global energy consumption. But making white LEDs isn't completely benign or budget friendly. To help reduce the environmental footprint and cost of these lights, researchers have developed the first white LED with a hybrid, metal-organic framework material. Their report appears in the journal ACS Nano.

Widespread use of low-power, long-lasting LEDs in the U.S. could save nearly 348 terawatt-hours by 2027, which equals the annual output of 44 power plants, according to the U.S. Department of Energy. But white LEDs are currently made with rare-earth elements, and mining these minerals can be costly and produce toxic waste. Additionally, existing commercial methods for producing white LEDs involve multiple components and steps that reduce efficiency and quality.

So, Kuang-Lieh Lu, Yang-Fang Chen and colleagues developed more cost-effective and environmentally friendly white LEDs using graphene and a strontium-based, (MOF) that does not include rare-earth elements. MOFs comprise a promising new class of hybrid materials made of metallic ions and organic ligands. Testing showed that the devices' emission spectrum was close to that of natural sunlight.

Explore further: New technology can expand LED lighting, cutting energy use and greenhouse gas emissions

More information: Electrically Driven White Light Emission from Intrinsic Metal-Organic Framework, ACS Nano, pubs.acs.org/doi/abs/10.1021/acsnano.6b03030.

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LED Guy
3.7 / 5 (3) Aug 31, 2016
A "cost effective" LED based on grapheme. Let's think about that statement by itself. LEDs are available in commercial quantities at <$0.07 each that deliver 180 lumens for 1W of electrical power input. That's a little over $0.30 for enough LEDs to deliver 800 lumens of light which is more than a standard 60W incandescent bulb.

MOF materials have a specific area (surface area/weight). It is one of their desirable features. Unfortunately the pore size associated with MOFs means that they are really great at absorbing moisture. Not an issue by itself, until you realize that the silicones used in producing LEDs are in fact permeable to moisture and that LEDs reach temperatures of >85C during operation. All that absorbed water will go somewhere and that isn't good for reliability.
gkam
1 / 5 (7) Aug 31, 2016
" silicones used in producing LEDs"
----------------------------

Silicones?
Uncle Ira
4.2 / 5 (10) Aug 31, 2016
" silicones used in producing LEDs"
----------------------------

Silicones?


Yeah glam-Skippy, silicones. Not being in the semiconductor or plastics business you would not know about the silicones.
gkam
1 / 5 (7) Aug 31, 2016
Show me where the silicones are used in ICs or LEDs.
Uncle Ira
4.2 / 5 (10) Aug 31, 2016
Show me where the silicones are used in ICs or LEDs.


What it is you think is the most common material for coating, sealing and encasing them Cher? You guess him, it's silicones. For an idiot, you are remarkable stupid.
gkam
1.5 / 5 (8) Aug 31, 2016
Silicones are not porous.

And they were not talking about the packaging.

Your need to attack me has its drawbacks, such as demonstrating your silly fixation on the person who bested you.

Uncle Ira
4.6 / 5 (9) Aug 31, 2016
Silicones are not porous.

And they were not talking about the packaging.

Your need to attack me has its drawbacks, such as demonstrating your silly fixation on the person who bested you.



Don't you wish they would do away with the "3-Minute-Take-It-Back-Because-It-Is-Stupid" rule? It is so unfair to you Cher. The words are still up there Cher, and your shift and dodge and steer it this way stuffs is so lame, it only draws more attention to how how much the idiot you are.
Estevan57
5 / 5 (7) Aug 31, 2016
@ Gkam -
https://www.shine...ex.shtml

5 more references here, but they keep disappearing, oh well.

Or in book form: Microelectronic Interconnections and Assembly
edited by G.G. Harman, Pavel Mach

Packaging refers to what it is encased within, Not what it is sold in. In the industry this is the meaning of packaging.

Try Google sometime, idiot.
TheGhostofOtto1923
5 / 5 (5) Aug 31, 2016
Your need to attack me has its drawbacks, such as demonstrating your silly fixation on the person who bested you
This reminds me of this older gentleman I used to work with. He had a corvette and was complaining about being hassled on the road by people trying to pass him. "Everybody wants to pass a corvette" was his explanation.

After a few questions it became apparent that he drove it like an old lady which is why everybody wanted to pass him.

Your egomania is like an old guy who drives a corvette at 30mph in a 50mph zone and thinks he is the center of attention because he is cool.

Nothing to envy about a 70+yo lying cheating psychopath who cant tell the difference between facts and the shit he makes up himself.

Its time for george kamburoff to stop driving.

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