Blue LEDs and the 2014 Nobel Prize in Physics - Sixty Symbols
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- Опубліковано 7 жов 2014
- The 2014 Nobel Prize in Physics goes to Isamu Akasaki, Hiroshi Amano and Shuji Nakamura for work on blue light emitting diodes (LEDs).
More physics Nobel Prize videos: bit.ly/SSNobel
Discussed by Tom Foxon and Laurence Eaves.
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When I studied electronics in the 1980's there was a fairly common consent that blue LED's would never be possible.
But... There are blue led everywhere!
People don't get the significance today.
I remember that! My father (I was still a teen in the 1980s, but Dad's an electrical engineer) was adamant that blue leds where physically impossible.
Nakamura also made the solid-state blue and violet laser diodes, which is also kind of a big deal.
When I was a kid, I tinkered a lot with electronics. I messed around with LEDs a LOT. Back then (in the early 80's), only Red, Orange, Yellow and Green were available, and the green ones were not really a pure green - they were a kind of washed-out yellow in green casing. I really, really wanted blue LEDs to be a thing. Electronics magazines occasionally predicted that they would soon be available, but it took over a decade of waiting before i saw my first Blue LED. It was very exciting. The early Blue LEDs were very dim - they were made with SiC instead of the GaInN ones they have now.
For me, Blue LEDs (and violet and UV) were a massive achievement, and I consider it to be an achievement worthy of a Nobel prize.
I miss radio shack
Yep, I saw those claims about blue leds, but my father who was an electrical engineer was adamant blue leds where impossible (And he was unconvinced by claims about white leds too), Guess the electronics mags and kits where right after all.
Watching this in 2024, realizing this channel had this video 9 years ago, just when he won the noble prize. Amazing work.
It certainly would have been nice for the video to inform viewers that the work described here happened 25 years ago. Not to mention giving an explanation of the significance of the work. As it is it is nothing more than a technical talk without context.
"As it is it is nothing more than a technical talk without context."
They are acting like engineers.
"It has gradually over the last 20 years been developed as a technology and it is now being used for lighting [..]"
People don't seem to understand that the Nobel price isn't usually given out within a short amount of time after a discovery but instead it usually takes several years for someone's discovery to get rewarded with the Nobel price which is the case of this award. The discovery is old but the people choosing who gets the award gave them the award at this time.
Sure, unless they're giving it to a president for simply having brown skin.
Yellow King The Nobel Peace Prize is a completely unrelated prize, awarded by a completely unrelated group
what's the cost of a nobel price?
***** Yeah. Different organizations. That are unrelated. Which is what I friggin' said, dude. How am I wrong if you proved me right?
***** Yeah, sure, I'll admit it: they're related. They're related the same way McDonalds is related to the Scottish. In name only. Please, let's continue this utterly pointless argument over details that don't matter, just you so you undermine my counter to a troll trying to dismiss the Nobel Prize in physics entirely because they disagree with the Nobel Peace Prize's politics. That's super productive.
One of my favorite channels of all time! Thank you for making these videos!
The fellow with the beard is my new favorite professor. He will of course loose this status as soon as a new video comes out with any of my other favorite professors but for now I am delighted with his explanation, his presentation, his presence and his manner.
I was hoping you'd upload this today. Thanks! :)
I really enjoyed Tom Foxon's explanation and would like to see him in more videos.
I had my ad-block disabled for a moment and got an advertisement for LEDs -_-
The fact that one of these guys was working in industry sounds very hopeful, showing that the pursuit of knowledge need not only occur in the university.
The figure describing the band gap was pretty poor..... It seems to imply that there is a physical gap between two materials, when the professor is actually talking about a gap in electron energy states within the atoms of a single material.
Holonyak created the first LED in 1962. Where is his prize?
shomolya So glad we got that opinion. That matters so much to us. It's not as if we're experts in the field who have been studying it minutely for the better part of our lives now, is it?
Regards,
The Nobel Committee.
shomolya Sure. Prove that your contribution to the world of science has opened avenues that have hitherto been closed, and take it.
keithcessna1 Blue/UV LED's were the 'Holy Grail' advancement for many reasons not so apparent.
The first is that short-wavelength light is easier to work with.
UV light can energize phosphors to get any color you want.
White light from a red/blue/green emitter is tricky, as each emitter uses a different voltage/current to get the same brightness.
Wide band gap is more efficient. Less electron energy wasted in heat, more energy into the photons. Less heat allows higher power input, greater photon intensity. Bright enough to light a room.
Not saying that the visible red LED does not deserve recognition.
It was a clear case of applying quantum mechanics to create a new device, and as such should be widely recognized.
But the blue LED took many decades of effort around the world to realize, even knowing 'how to' do it.
Very educative, thank you for the video
Good info. What surprised me was the discount the IR LED's; the vey basis of most sensors and remote controls.
can you make a vid explaining the 2016 nobel prize in physics or chemistry
This was a big surprise for me when I heard it first. On a second thought I realized what a great impact blue led mad.
We already had red and green LEDs, but when blue came along. We finally had white LED light. What it led (pun?) to was incredible.
low power LED household light bulbs
LED daytime running lights for cars... Audi paved the way on this back in the day and it's now everywhere
LED backlights for monitors and TVs
OLED screens, leading to better displays for smartphones
LED camera flashes for smartphones
Colored ambient lighting (well...)
LED flashlights which if needed can even be operated by hand crank.. IKEA :)
running out of ideas...
but it's clear that the blue LED opened up so many paths for various industries to exploit.
I'll have to watch it a few times to completely get it, but sounds cool!
Do a detailed video about the Majorana particle! :)
I bet the inventors of the Red and Green LEDs are jealous of these Nobel prize winners.
Green with envy, no doubt.
This is interesting to me as someone who is taking a theatrical lighting course. My professor is always talking about the future of LEDs, but we never go much into the science of it because incandescent lamps are still the primary type used.
Will increasing the gap have an impact on the light wavelength? I am thinking it might decrease the wavelength?
How is the hole in thet P type cleared again to accept another electron?
I remember the first blue winky light I ever saw on a piece of consumer electronics. It was a several thousand dollar home stereo system back in the late 80s, early 90s.
Now virtually every piece of tech I own has them. Just within eyesight in my bedroom I count 5. My new motorola cable modem is lousy with them.
What does electrically active and doped mean?
This seemed like a lot of info in one video. Not that I'm complaining.
Could you do smth about Memristors?
I would love to see a video of the 60-Symbols crew discussing the process of doping semicondutors.
Why do the p- and n-types have to be eletrically charged (not inert) ? Doesnt douping mean that despite adding holes/eletrons to the material being douped, an according number of protons are added as well - thus both types remain inert.
I dont understand why the scientists needed their p- or n-types to be eletrically charged for the experiment to work.
Someone care to explain?
The thing that I don't understand is, how does the entire LED crystal emit light? Isn't it a 2 piece material, n and p layers touching? Sounds like only light from the contact face should be emitted.
A shame the original inventor of the LED wasn't included :(
Nice to see some new faces - great vid.
Brady you should do a funny video where you get all of the older professors to draw circles for you on brown paper. :)
That's so dope...
I'd love to hear more about semiconductor technology.
How do you get rid of the electron in the N-doped material? Isnt that necessary for this to be continous?
You run a current through it, I think (I don't know much about semiconductors). From what I understand, as the current crosses the semiconductor, it pushes electrons out of the N-type material, forcing them to cross the gap (band gap?) and be received by the P-type material. When this happens, the electron drops to a lower energy state, it emits a photon, and the current continues normally.
Amusing mechanism to generate photons of specific wavelength.
@Lepthymo than what are photons?
Isn't there a similar story with the blue laser? I think one man came up with that as well
Excellent video!
LEDs have come a long ways! Use to pick them up at Radio Shack many years ago (early 80's). Was excited to get my first blue LED in the early 1990's ! Expensive back then! Now my house is let using LEDs. Never thought it would be possible, but never say never I suppose!
Amazing video to stumble on from the future where the common trope is to hate blue led's 🤔 I get why people hate them, but it is do awesome to see the science of where they came from and why they were such an important breakthrough
Is this also the reason why COLOR LCD's with RGB subpixels could exist? Is the blue subpixel bigger than the Red subpixel?
I dont understand it all but I am mesmerized. I adore smart people. Jeff in Ohio 🇺🇸
Hey Brady, when's the next HI podcast?
Steve Weiss, while trying to sound so authoritative, has made three large errors in his post below.
He said that "Prof Nick Holonyak's pioneering work on led's in 1962 made the more recent developments possible. His first graduate student at the University of Illinois was John Bardeen who won two Nobel prizes for the development of the transitor and the integrated curcuit. That work was done at Bell labs."
Holonyak was Bardeens' grad student, the opposite of what Steve said.
John Bardeen's first Nobel prize was indeed awarded to him (and two others) for the invention of the transistor. And at the time, they were all working at Bell Labs.
However, his second Nobel was for for a fundamental theory of conventional superconductivity known as the BCS theory, which led to the MRI. He was at the University of Illinois when he did this work. His first grad student invented the LED (red)
in 1962.
Bardeen did not invent the IC. That was invented by Jack Kilby while working at Texas Instruments.
Bardeen is the only person to win two Nobel prizes in Physics.
I have some old blue LEDs that use Silicon Carbide
I have seen blue LED's on torches way before these guys made a "blue LED" can someone please tell me the difference?
And the earlies commercially sold orange and green LEDs were just red diode in a dyed shell. So as soon as you fired your new expensive green LED up, it lit red.
Ahh up to date physics news with an actual explanation of why they won?!?! I wish i could thank Brady personally...
What makes the electrons travel through the gap?
The gap is not a thing the electrons have to travel through. If you draw a graph of the energy levels that the electrons have, some are high and some are low. There is a gap in the middle. When an electron goes from a high energy level to a low energy level it emits a photon. The width of the gap is the amount of energy released.
They seem great teachers
Hey look ... it's doctor, professor, Gandalf The Awesome :D
More energy is a amazing idea. It deserves the prize. Do you know how to grow more plants, with less energy used? Do you know how we explore the ocean. Faster Internet? Convert whole cities to LEDs... The savings. While I'm not the best a physics, I appreciate the magnitude of the discovery. I appreciate the efficient energy. Thank you for sharing. This technology has dominated my industry already (Aquatics) and because of this discovery, we can do things we never could 20 years ago.
What is it different from already created blue light or rgb LEDs?
Whats different? At this time neither blue nor rgb LEDs did exist.
What they invented laid the foundation, first for blue and later
for white LEDs
This was done back in the 80's.
The first blue LEDs (early 90's) used silicon carbide and were very dim.
Does this mean that the white LEDs on my desk also emit UV light?
2:50
I still don't understand how you go from UV light to blue, could someone please explain this
They're referring to the technique used in fluorescent light bulbs where you use phosphorus to turn the UV light into visible light.
This technique is rather old. The light from any fluorescent light bulb you've seen starts as UV light inside the bulb too. This UV light then strikes the white coating around the light bulb, which is made of phosphorus, which shines bright because of it.
It is obviously way more complex than this, but that's the overall idea.
They're making use of phosphorescence. A fluorescent light or a CRT screen relies on the same principle. You have a substance which when excited, by being hit with a sufficiently energetic photon or an electron, will emit light for a little while as its electrons drop down to lower energy levels.
You might have noticed how fluorescent tubes glow faintly for a little while after you turn them off. That's phosphorescence in action.
Thanks guys
Without blue LED , we couldn't make white LED. This technology is now used as TV , smartphones , pc display and more.
What happened with the primordial gravity waves??? I thought that was a big thing.
Do you mean the Bicep-2 results?
I'm pretty sure those need some more backup by other observatories (maybe even a dedicated space telescope) to be considered.
The implications are pretty big and the signal to noise ratio seems hard to overcome.
But hey, the blue LEDs needed some 20 years to get there and the Bicep-2 team looked pretty young. They got time. =)
now let's make gamma LEDs!!
I find this video's animations disturbingly inaccurate. There's nothing like physical gap in the LED. The n-doped and p-doped layers are directly touching each other. And the light is not produced as the electron passes the "gap" but only after it has already settled on the other side.
In reality it works like this: The P-N junction forms a potential barrier. Electrons need certain energy to pass through it and they get the energy from the electric field. When the electron has enough energy, it passes the P-N potential barrier and is captured by the material on the other side of the junction, but it still has its energy. It parks on a high energy level of the molecule, and tries to settle in the lowest energy state. But since there is the energy gap in the material, it must emit a photon of visible light to get there. And that's when the light gets emitted.
That makes so much more sense. He was switching back and forth between describing it as a gap in energy potential and a physical gap.
Get off your high horse. There was no way they could have conveyed that in a diagram that would be easily understood by all viewers. The model that they used is a fine analogy for its purpose.
TheZanyCat
kashua seems to convey in a paragraph what you say couldn't be conveyed in a properly described diagram.
Would you want them to talk about MO-Theory or the Pauli Exclusion Principle just as a side note? He has to make these videos understandable for a broad spectrum of people. I think it was a pretty good animation, although you're right about the emission of the photon, he could have delayed that a bit.
Did you by any chance get the idea for this video from a Reddit post on ELI5, Brady?
0:14 - Did someone lose their duster?
Lol at mind the Gap. I'm almost surprised someone from the UK would make the joke at this point as it seems like something I'd think you would be sick of hearing about ;-) on my vacation to London some years back mind the gap was everywhere. :-)
Can you make a video on why universe is flat/horizontal?
What if it's not
I am not saying it is completely flat or horizontal but If you at its shape then you will notice that shape of galaxy or solar system is more spread horizontally than vertically or in some other direction.
The universe experiences anisotropy because any cloud of dust, even if it seems to move randomly has a net rotation about a plane. This is proven in three dimensions. This means when dust clouds collapse they do so on to this virtual plane, and as everything up to and including galaxies were formed from clouds of gas or stars, their formation was around one of these planes, thus everything is flat to a greater or lesser degree.
People might question on the importance of this, and ask, why blue?
well, yellow,orange,blue,pure white, warm white, are all essentially "BLuE" because emitting blue color is most energy efficient, and they then pour in some slightly yellow colored dye on it later to make the eye-stinging blue to a soothing milky white or to a classic warm incandescent yellow color.
i think these people work for CREE and they have made the most energy efficient led mankind has ever seen (i guess they got a Guiness world record for it)
info.zip extracted for you
What does 'dope' mean? And can anyone explain to me properly what these holes (p-type) are?
Imagine a solid lattice, where all of the atoms are equally spread apart based on some spatially efficient scheme. Let's say these atoms are silica atoms. Well, Silicon has 4 electrons in it's outermost shell. If we wanted to make the silica (as a whole) more negative, we could replace some of the silicon with an atom that has more electrons (like phosphorus). If we wanted it to be more positively charged, we could replace some of the silicon with an atom with less electrons (like boron). This process of exchanging silica for other atoms with more or less electrons is called "doping."
If we make the silica more positive (by removing electrons), it is called "p-type." If we make the silica more negative (by adding electrons), it is called "n-type." Because we have removed electrons from the "p-type" silica (which is in a solid lattice), there are holes where the electrons should be. These holes want to be filled, but cannot unless there is an electron source nearby (potentially an "n-type" semiconductor nearby).
I hope it helps!
It has to do with how semiconductors are made. Doping basically means laying the layer of material. The p-type layer is the layer that attracts the electrons (Think P like postive and N like negative)
MrZeyami
doping means adding an impurity to the semi-conductor material.
LeiosOS How do you pluck atoms out of a lattice like that?
LeiosOS Yeah that's cleared it up, thank you:)
Now the challenge is how to make an efficient Green LED.
Heartiest Congratulations!
With warm regards + best wishes
Sameen Ahmed KHAN
Engineering Department
Salalah College of Technology,
Salalah, Sultanate of OMAN.
Nice, now I understand =)
I'm not sure I understand why this breakthrough was awarded the Nobel prize instead of just being regarded as a feat of engineering. Does anyone have insight on that?
This is a really great achievement. Congratulations to those who discovered it. I do think however that those who are implementing the use of these UV diodes should consider the impacts they have on nature, notably outdoor street lighting which may be a large use of these. The International Dark Sky Association has brought to my attention how many insects are incredibly attracted to these.
www.darksky.org/assets/documents/IDA-Blue-Rich-Light-White-Paper.pdf
so is light is literally the ripples moving electrons make? If that's so then I just had a massive epiphany
Pretty much. The electron is the force carrier for the electromagnetic force which includes light.
brooksy54321 NO! The photon is the force carrier particle for the electromagnetic force. The electron excites the electromagnetic field thus emitting a photon if the excitation is enough. In this case, when recombining, the electron-hole pair looses energy to emit a photon.
Oooooooooooooooops! College physics has failed me....or did I fail it!
brooksy54321 hmm you learned about force carrier particles in college physics. unlikely
mikestoneadfjgs I learned that the photon is the carrier of the electromagnetic force multiple times on UA-cam, and they even mentioned it, along with the quark composition of sub-atomic particles, in my high school chemistry class.
wow that squiggly photon really was blue!
And yet, the man that ACTUALLY invented LEDs didn't get crap.
Magnificent beard.
And another questions, What's the difference betweena RGB Pixel on my Computer monitor and a LED?
An LED emits light, your (likely lcd) monitor uses filters to block light rather than emit it. To show a blue pixel it blocks the green and blue from the white back light. However, some more recent monitors/screens using OLED's actually have every pixel on the screen emit their own light, in which case a 1080x1920 screen essentially has 6 million individually controlled variable intensity led's.
Jason Bass That's amazing! And thanks for your answer!
Another question, why can't we make LED pixels, why do we have to rely on organic compounds to make small LED's work? is it because of the constraints to size when it comes to inorganic's?
Basically, look up pictures of led's under under a microscope. If you can figure out how to make one of those on the scale of a single pixel, you deserve an award.
Possibly, but would it be cost effective?
Jason Bass wouldn't have a clue, thought LED's were cheap as?
Those of us in the know waited for decades for the blue LED.
The Nobel prize was worthy, don'tcha think?
In my life, I have seen a slow evolution and shift from incandescent to LED in many areas, such as cheap $1 store junk, flashlights, indicators, etc. I also that if something did have in LED indicator light on it, it was usually either lime green or red, nowadays it is often deep green, bright red, white, or blue! white and blue LEDs I remember used to cost a lot, and I still value them, but now they cost the same as any other color LED!
White and blue are still more expensive then red and green - it just that LEDs are - generally speaking - relatively cheap. So blue and white cost a multiple of a green or red led, but if a few cents in product price don´t matter do much its worth it.
sarowie I suppose so, but the price difference (for small quantities) is almost negligible, at least when it comes to getting them from eBay instead of proper suppliers.
Power Max
LEDs are relatively cheap. When you order 100 or so from an electronic component supplier you see a clear difference. But then you see the shipping price and well: The shipping might be the most expensive thing in the order.
For products that contain LEDs it mean: If the marketing thinks, blue led look good, they cost just a few cents so: Go for it. If the company as to count every penny, just take the red or a green one.
Don't forget about RGB LEDs. They still amaze me, but they also cost much more than single color LEDs.
Gunhaver Yup. I don't question that, and the fact that white LEDs are simply blue LEDs with a broad yellow YAG phosphor applied on top of them to convert some of the blue emission (I think around 450nm)to other colors to make white, also leading to that characteristic purplish white hue for low CRI high color temp. LEDs, as well as the classic spectrum emission curve.
I don't get it, we already have blue and UV leds, what new did these guys come up with?
they did come up with exactly those LEDs you are talking about.
THEY discovered and executed the first process to make those leds.
The Nobel Prize for physics usually gets rewarded years or decades after the discovery or breakthrough.
They created the first blue led decades ago but only now they received a Nobel prize.
They did it in the early 1990s
It's a bit early for Santa ;)
Not to get too pushy, but the next step needs to be the production of BIGGER LEDs. Why are they so small?
My mates got one of them Nobel prize things and for a few £ says he can get me one too and I don't even use blue LED's so there ! what do you think of that ?
Would have like to see more about why this deserves a Nobel prize. I mean, sure, i can't do what they did so maybe i shouldn't judge, but to me it sounds like they made a blue LED. Don't we already have those?
Yes, they invented it. It's not a prize for new invention, but for what they achieved twenty years ago or so.
30LayersOfKevlar Ah ok. That makes more sense. Thanks.
BennyDACHO I agree with this sentiment, and I'm also scratching my head why this is winning the Physics category and not the Chemistry category.
Throughout the video he focused on the properties of various compounds, and manipulating those properties with the additions of other element/compounds to achieve desired results. Can someone explain how this is physics and not chemistry?
***** Chemistry deals with the bonds between atoms and molecules and what matter is made of. Physics deals with what happens inside the atom, and on a scale much smaller than chemistry. And since what they achieved has more to do with how electrons move between energy states than with what material that thing is made of, it does make a bit of sense for it to be in physics.
Declan Siewert Yes, it's true. But you have to admit it would have made more sense if they said that the prize isn't for recent work.
what no comments!?
So they're not blue, then? You can argue they're white or you can argue that they're ultraviolet but you can't argue that they blue. Bear in mind that once you have ultraviolet light you can coat the inside of the bulb in phosphorous to produce white light. After you have produced white light, you can then put a coloured translucent casing around it, like you do in traffic lights, and get whatever colour you like. They use these LEDs with the different light filters as pixels to generate images in LED TV screens.
I actually invented this idea in a university project.
Has this made black lights cheaper?
I didn't even know that blue LEDs didn't exist
mind the gap hahah made me chuckle. great video :)
Captain Barbossa
This was important, but it's kind of funny that this wasn't given to the inventor of LEDs, or the makers of the first blue LED.
I thought it was, back in the 1990s (...?)
And there these guys are 20 years later and unemployed, sitting there with a bottle of vodka in a paper bag watching Pornhub and suddenly get a phone call. "Hey Mr. Akasaki, yes hi. Great news, you won the Nobel Prize". "Uhhmm... for what?" "The one thing with the LEDs when they were stuck trying to make the final blue Tamagotchi and finish the set. Remember?" "Oh yeah! Fuck, wow? Ok coo... let me find some pants."
The blue led on my Viper alarm is cool. but nobel prize worthy?
havent they seen something like oh i dont know THE SKY before ??! .........
The sky's "blueness" is due to Reayleigh scattering (same as why some eyes are blue). It's a bit of a different story.
That was actually one of the more retarded comments I've read anywhere on the internet.
Why don't you create a planet? Haven't you seen something like oh i dont know the EARTH before??!....
Take an LED and cover it with blue tinted glass. Bam! Blue LED.
That would make a black LED, i.e. it wouldn't work.That would just absorb non-blue light, which makes your idea utterly useless.
People put filters on lights all the time to make them shine a different color.
And how does a filter work? It absorbs some light and lets some of a certain wavelength through. How exactly would this work on an LED, which produces light with discrete wavelengths, considering the light emitted is is from electrons changing energy levels - discrete energy levels? If you put blue-tinted glass over an LED which doesn't emit blue light then all of the non-blue light will get absorbed, i.e. you'll then have no light.
Sounds like a trivial pursuit to me.... am I wrong?