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  • - LEDs don't get their color from their plastic covers.

  • And you can see that because here is a transparent LED

  • that also glows the same red color.

  • The color of the light comes

  • from the electronics themselves.

  • The casing just helps us tell different LEDs apart.

  • In 1962, general Electric engineer Nick Holonyak

  • created the first visible LED.

  • It glowed a faint red.

  • A few years after that, engineers at Monsanto

  • created a green LED.

  • But for decades, all we had were those two colors.

  • So LEDs could only be used in things like indicators,

  • calculators, and watches.

  • If only we could make blue, then we could mix

  • red, green, and blue to make white,

  • and every other color,

  • unlocking LEDs for every type of lighting in the world,

  • from light bulbs, to phones, to computers,

  • to TVs to billboards.

  • But blue was almost impossible to make.

  • (dramatic music)

  • Throughout the 1960s,

  • every big electronics company in the world,

  • from IBM to GE, to Bell Labs,

  • raced to create the blue LED.

  • They knew it would be worth billions.

  • Despite the efforts of thousands of researchers,

  • nothing worked.

  • 10 years after Holonyak's original LED

  • turned into 20, then 30,

  • and the hope of ever using LEDs for light, faded away.

  • According to a director at Monsanto,

  • these won't ever replace the kitchen light.

  • They'd only be used in appliances, car dashboards,

  • and stereo sets to see if the stereo was on.

  • This might still be true today, if not for one engineer

  • who defied the entire industry

  • and made three radical breakthroughs

  • to create the world's first blue LED.

  • (dramatic music)

  • Shūji Nakamura was a researcher at a small Japanese chemical

  • company named Nichia.

  • They had recently expanded into the production

  • of semiconductors to be used in the manufacture

  • of red and green LEDs.

  • But by the late 1980s,

  • the semiconductor division was on its last legs.

  • They were competing against far more established

  • companies in a crowded market, and they were losing.

  • Tensions started to run high.

  • Younger employees begged Nakamura to create new products,

  • while senior workers called his research a waste of money.

  • And at Nichia, money was in short supply.

  • Nakamura's lab mainly consisted of machinery

  • he had scavenged and welded together himself.

  • Phosphorus leaks in his lab created so many explosions,

  • that his coworkers had stopped checking in on him.

  • By 1988, Nakamura's supervisors were so disillusioned

  • with his research that they told him to quit.

  • So it was out of desperation

  • that he brought a radical proposal to the company's founder

  • and president Nobuo Ogawa.

  • (dramatic music)

  • The elusive blue LED,

  • that the likes of of Sony, Toshiba and Panasonic

  • had all failed at.

  • What if Nichia could be the one to create it?

  • After suffering loss after loss on their semiconductors

  • for more than a decade,

  • Ogawa took a gamble.

  • He devoted 500 million yen or $3 million,

  • likely around 15% of the company's annual profit,

  • to Nakamura's moonshot Project.

  • Everyone knew that LEDs have the potential

  • to replace light bulbs,

  • because light bulbs, the universal symbol for a bright idea,

  • are actually terrible at making light.

  • They work by running current through a tungsten filament,

  • which gets so hot, it glows.

  • But most of the electromagnetic radiation

  • comes out as infrared, heat.

  • Only a negligible fraction is visible light.

  • In contrast, LED stands for light emitting diode.

  • It's right there in the name.

  • LEDs primarily create light, so they're far more efficient,

  • and a diode is just a device with two electrodes,

  • which only allows current to flow in one direction.

  • So here's how an LED works.

  • When you have an isolated atom,

  • each electron in that atom occupies a discreet energy level.

  • You can think of these energy levels like individual seats

  • from a hockey stadium,

  • and all atoms of the same element,

  • when they are far apart from each other

  • have identical available energy levels.

  • But when you bring multiple atoms together to form a solid,

  • something interesting happens.

  • The outermost electrons now feel the pole,

  • not only of their own nucleus,

  • but of all the other nuclei as well.

  • And as a result, their energy levels shift.

  • So instead of being identical,

  • they become a series of closely spaced,

  • but separate energy levels.

  • An energy band.

  • The highest energy band with electrons in it,

  • is known as the valence band,

  • and the next higher energy band

  • is called the conduction band.

  • You can think of it like the balcony level.

  • In conductors, the valence band is only partially filled.

  • This means with a little bit of thermal energy,

  • electrons can jump into nearby unfilled seats,

  • and if an electric field is applied,

  • they can jump from one unfilled seat to the next

  • and conduct current through the material.

  • In insulators, the valence band is full,

  • and the difference in energy between the valence

  • and conduction bands, the band gap, is large.

  • So when an electric field is applied, no electrons can move.

  • There are no available seats

  • to move into in the valence band,

  • and the band gap is too big for any electrons

  • to jump into the conduction band,

  • which brings us to semiconductors.

  • Semiconductors are similar to insulators,

  • except the band gap is much smaller.

  • This means at room temperature,

  • a few electrons will have sufficient energy

  • to jump into the conduction band,

  • and now they can easily access nearby empty

  • seats and conduct current.

  • Not only that, the empty seats they left

  • behind in the valence band can also move.

  • Well, really, it's the nearby electrons

  • jumping into those empty seats.

  • But if you look from afar,

  • it's as though the empty seat or hole

  • is moving like a positive charge in the opposite

  • direction to the electrons in the conduction band.

  • (soft music)

  • By themselves, pure semiconductors are not that useful.

  • To make them way more functional,

  • you have to add impurity atoms into the lattice.

  • This is known as doping.

  • For example, in silicon,

  • you can add a small number of phosphorus atoms.

  • Phosphorus is similar to silicon,

  • so it easily fits into the lattice,

  • but it brings with it one extra valence electron.

  • This electron exists in a donor level

  • just beneath the conduction band.

  • So with a bit of thermal energy,

  • all these electrons can jump into the conduction band

  • and conduct current.

  • Since most of the charges that can move

  • in this type of semiconductor are electrons,

  • which are negative,

  • this sort of semiconductor is called n-type,

  • n for negative,

  • but I should point out that the semiconductor

  • itself is still neutral.

  • It's just that most of the mobile charge

  • carriers are negative.

  • They're electrons.

  • So there is also another type of semiconductor where most

  • of the mobile charge carriers are positive,

  • and it's called p-type.

  • To make p-type silicon,

  • you add a small number of atoms of, say, boron.

  • Boron fits into the lattice,

  • but brings with it one fewer valence electron than silicon.

  • So it creates an empty acceptor level

  • just above the valence band.

  • And with a bit of thermal energy,

  • electrons can jump outta the valence band,

  • leaving behind holes.

  • It is these positive holes which are mostly responsible

  • for carrying current in the p-type semiconductor.

  • Again, the material overall is uncharged,

  • it's just that most of the mobile charge carriers

  • are positive holes.

  • Where things get interesting is when you put a piece

  • of p-type and n-type together.

  • Without even connecting this to a circuit,

  • some electrons will diffuse from n to p

  • and fall into the holes in the p-type.

  • This makes the p-type a little negatively charged,

  • and the n-type a little positively charged.

  • So there is now an electric field

  • inside an inert piece of material.

  • Electrons keep diffusing

  • until the electric field becomes so large,

  • it prevents them from crossing over.

  • And now we have established the depletion region,

  • an area depleted of mobile charge carriers.

  • There are no electrons in the conduction band

  • and no holes in the valence band.

  • If you connect a battery the wrong way to this diode,

  • it simply expands the depletion region

  • until its electric field perfectly opposes that

  • of the battery and no current flows.

  • But if you flip the polarity of the battery,

  • then the depletion region shrinks,

  • the electric field decreases,

  • and electrons can flow from n to p.

  • When an electron falls from the conduction band into a hole

  • in the valence band, that band gap energy can be

  • emitted as a photon.

  • The energy change of the electron is emitted as light,

  • and this is how a light emitting diode works.

  • The size of the band gap determines the color

  • of the light emitted.

  • In pure silicon, the band gap is only 1.1 electron volts.

  • So the photon released isn't visible, it's infrared light.

  • These LEDs are actually used in remote controls

  • for your TV, and you can capture them on camera.

  • Moving up the spectrum, you can see why the first visible

  • light LEDs were red and then green,

  • and why blue was so hard.

  • A photon of blue light requires more energy,

  • and therefore a larger band gap.

  • By the 1980s,

  • after hundreds of millions of dollars had been spent hunting

  • for the right material, every electronics company

  • had come up empty handed.

  • But researchers had at least figured out

  • the first critical requirement, high quality crystal.

  • No matter what material you used for the blue LED,

  • it required a near perfect crystal structure.

  • Any defects in the crystal lattice,

  • disrupt the flow of electrons.

  • So instead of emitting their energy as visible light,

  • it is instead dissipated as heat.

  • So the first step in Nakamura's proposal to Ogawa,

  • was to disappear to Florida.

  • He knew an old colleague there whose lab was beginning

  • to use a new crystal making technology called

  • Metal Organic Chemical Vapor Deposition,

  • or MOCVD.

  • An MOCVD reactor, essentially a giant oven,

  • was and still is the best way to mass produce clean crystal.

  • It works by injecting vapor molecules

  • of your crystal into a hot chamber where they react

  • with a base material called a substrate to form layers.

  • It's important that the substrate lattice matches

  • the crystal lattice being built on top of it

  • to create a stable, smooth crystal.

  • This is a precise art.

  • The crystal layers often need to be as thin

  • as just a couple of atoms.

  • Nakamura joined the lab for a year to master MOCVD.

  • But his time there was miserable.

  • He wasn't allowed to use the working MOCVD,

  • so he spent 10 of his 12 months assembling a new system,

  • almost from scratch.

  • Even worse, his lab mates shunned him

  • because Nakamura didn't have a doctorate,

  • nor any academic papers to his name,

  • as Nichia didn't allow publishing.

  • His lab mates, all PhD researchers,

  • dismissed him as a lowly technician.

  • This experience fueled him.

  • Nakamura wrote, "I feel resentful

  • when people looked down on me.

  • I developed more fighting spirit.

  • I would not allow myself to be beaten by such people."

  • (inspirational music)

  • He returned to Japan in 1989 with two things in hand.

  • One, an order for a brand new MOCVD reactor for Nichia,

  • and two, a fervent desire to get his PhD.

  • At that time in Japan, you could earn a PhD

  • without having to go to university,

  • simply by publishing five papers.

  • Nakamura had always known his chances

  • of inventing the blue LED were low.

  • But now he had a backup plan.

  • Even if he didn't succeed, he could at least get his PhD.

  • But now the question was with MOCVD under his belt,

  • which material should he research?

  • By this time, scientists had narrowed the options down

  • to two main candidates, zinc selenide, and gallium nitride.

  • These were both semiconductors with band gaps,

  • theoretically, in the blue light range.

  • Zinc selenide was the far more promising option.

  • When grown in an MOCVD reactor,

  • it had only a .3% lattice mismatch

  • with its substrate, gallium arsenide.

  • Therefore, zinc selenide crystal had about a thousand

  • defects per square centimeter,

  • within the upper limit for LED functioning.

  • Its only issue was that while scientists

  • had figured out multiple different

  • ways to create n-type zinc selenide,

  • no one knew how to create p-type.

  • In contrast, gallium nitride had been abandoned

  • by almost everybody for three reasons.

  • First, it was much harder to make a high quality crystal.

  • The best substrate for growing gallium nitride was sapphire,

  • but its lattice mismatch was 16%.

  • This resulted in higher defects,

  • over 10 billion per square centimeter.

  • The second problem was that like zinc selenide,

  • scientists had only ever created

  • n-type gallium nitride using silicon.

  • P-type was elusive.

  • And third, to be commercially viable,

  • a blue LED would have to have a total light output power

  • of at least a thousand microwatts.

  • That's two orders

  • of magnitude more than any prototype had ever achieved.

  • So between the two candidates,

  • almost all researchers were focused on zinc selenide.

  • Nakamura surveyed the crowded field

  • and decided that if he were going

  • to publish five papers by himself,

  • he'd better focus on gallium nitride,

  • where the competition was much less fierce.

  • This material's main claim

  • to fame was one development back in 1972,

  • when RCA engineer Herbert Maruska made a tiny

  • gallium nitride blue LED, but it was dim and inefficient.

  • So RCA slashed the project's budget, calling it a dead end.

  • 20 years later, scientific opinion hadn't changed.

  • When Nakamura attended the biggest applied physics

  • conference in Japan, the talks on zinc selenide

  • had over 500 attendees.

  • The talks on gallium nitride had five.

  • (dramatic music)

  • Two of those five attendees were the world experts

  • on gallium nitride, Dr. Isamu Akasaki

  • and his former grad student, Dr. Hiroshi Amano.

  • In contrast to Nakamura's academic background,

  • they were researchers at Nagoya University,

  • one of Japan's best.

  • A few years earlier, they had made a breakthrough

  • on the first problem of high quality crystal.

  • Instead of growing gallium nitride directly on sapphire,

  • they first grew a buffer layer of aluminum nitride.

  • This has a lattice spacing in between that

  • of the other two materials, making it easier

  • to grow a clean gallium nitride crystal on top.

  • The only issue was that the aluminum caused problems

  • for the MOCVD reactor,

  • making the process hard to scale.

  • But Nakamura wasn't even close at this stage.

  • Back at Nichia, he couldn't get gallium nitride to even grow

  • normally in his new MOCVD reactor.

  • After six months, desperate for results,

  • he decided to take the machine apart

  • and build a better version himself.

  • His 10 months spent putting together the reactor in Florida,

  • were suddenly invaluable.

  • He began following the same routine each day,

  • arrive at the lab at 7:00 AM.

  • Spend the first half

  • of the day welding, cutting, and rewiring the reactor.

  • Spend the rest of the day experimenting

  • with the modified reactor to see what it can do.

  • At 7:00 PM go home, eat dinner, wash and sleep.

  • Nakamura repeated this routine every single day,

  • taking no weekends

  • and no holidays except for New Year's Day,

  • the most important holiday in Japan.

  • (soft music)

  • After a year and a half of continuous work,

  • he came into the lab on a winter day in late 1990.

  • As usual, he tinkered around in the morning

  • grew a gallium nitride sample in the afternoon,

  • and tested it.

  • But this time, the electron mobility was four times higher

  • than any gallium nitride ever grown directly on sapphire.

  • Nakamura called it the most exciting day of his life.

  • His trick was to add a second nozzle

  • to the MOCVD reactor.

  • The gallium nitride reactant gases had been rising

  • in the hot chamber,

  • mixing in the air to form a powdery waste.

  • But the second nozzle released a downward stream

  • of inert gas, pinning the first flow to the substrate

  • to form a uniform crystal.

  • For years, scientists had avoided adding a second stream

  • to MOCVD because they thought it would only

  • introduce more turbulence.

  • But Nakamura used a special nozzle

  • so that even when the streams combined,

  • they remained laminar.

  • He called his invention the two-flow reactor.

  • Now, he was ready to take on Akazaki and Amano,

  • but instead of copying their aluminum nitride buffer layer,

  • his two flow design allowed him to make gallium nitride

  • so smooth and stable, it itself could be used

  • as a buffer layer on the sapphire substrate.

  • This in turn, yielded an even cleaner crystal

  • of gallium nitride on top,

  • without the issues of aluminum.

  • Nakamura now had the highest quality

  • gallium nitride crystals ever made.

  • But just as he was getting started,

  • things took a wrong turn.

  • (dramatic music)

  • While he had been in Florida,

  • Nobuo Ogawa had stepped back from Nichia to become chairman.

  • In his day, Nobuo had been a risk taking scientist,

  • designing the company's first products.

  • It's why he supported Nakamura's lofty plans all this time.

  • But in his place, his son-in-law, Eji Ogawa,

  • became CEO of the company,

  • and the younger Ogawa had a much stricter outlook.

  • One Nichia client said,

  • "He has a mind of steel,

  • and he remembers everything."

  • In 1990, an executive at Matsushita,

  • an LED manufacturer and Nichia's biggest customer,

  • visited the company to give a talk on blue LEDs.

  • In it, he claimed zinc selenide was the way forward,

  • declaring "gallium nitride has no future."

  • That very same day, Nakamura received a note from Eji,

  • stop work on gallium nitride immediately.

  • Eji had never supported the research

  • and wanted to end what he saw as a colossal waste.

  • But Nakamura crumpled up the note and threw it away,

  • and he did so again, and again,

  • when a succession of similar notes

  • and phone calls came from company management.

  • Out of spite, he published his work on the two-flow reactor

  • without Nichia's knowledge.

  • It was his first paper.

  • One down, four to go.

  • With crystal formation settled,

  • he turned to the second obstacle,

  • creating p-type gallium nitride.

  • Here Akazaki and Amano had again beaten him to the punch.

  • They had created a gallium nitride sample doped

  • with magnesium, but at first,

  • it didn't perform as a p-type as they expected.

  • However, after exposing it to an electron beam,

  • it did behave as a p-type,

  • the world's first p-type gallium nitride,

  • after 20 years of trying.

  • The catch was that no one knew why it worked.

  • And the process of irradiating each crystal

  • with electrons was too slow for commercial production.

  • At first, Nakamura copied Akazaki and Amano's approach,

  • but he suspected the beam of electrons was overkill.

  • Maybe all the crystal needed was energy.

  • So he tried heating magnesium doped gallium nitride

  • to 400 degrees Celsius in a process known as annealing.

  • The result, a completely p-type sample.

  • This worked even better than the shallow electron beam,

  • which only made the surfaces of the samples p-type,

  • and simply heating things up was a quick scalable process.

  • His work also revealed why the p-type had been so difficult.

  • To make gallium nitride

  • with MOCVD, you supply the nitrogen from ammonia,

  • but ammonia also contains hydrogen.

  • Where there should have been holes in the magnesium

  • doped gallium nitride,

  • these hydrogen atoms were sneaking in

  • and bonding with the magnesium, plugging all the holes.

  • Adding energy to the system,

  • released the hydrogen from the material,

  • freeing up the holes again.

  • (dramatic music)

  • By now, Nakamura had all the ingredients

  • to make a prototype blue LED,

  • and he presented it at a workshop in St. Louis in 1992

  • and received a standing ovation.

  • He was beginning to make a name for himself,

  • but even though he had created the best prototype to date,

  • it was more of a blue violet color

  • and still extremely inefficient,

  • with a light output power

  • of just 42 microwatts,

  • well below the 1000 microwatt threshold for practical use.

  • At Nichia, the new CEO's patience had run out.

  • Eji sent written orders to Nakamura to stop tinkering

  • and turn whatever he had into a product.

  • His job was on the line,

  • but in Nakamura's own words, "I kept ignoring his order.

  • I had been successful because I didn't listen

  • to company orders and trusted my own judgment."

  • At this point, he only had the third hurdle left,

  • getting his blue LED to a light output power

  • of a thousand microwatts.

  • (soft music)

  • A known trick to increase the efficiency of LEDs

  • was to create a well,

  • a thin layer of material at the p-n junction

  • called an active layer

  • that shrinks the band gap just a bit.

  • This encourages more electrons

  • to fall from the end type conduction band into holes

  • in the p-type valence band.

  • The best active layer for gallium nitride was already known

  • to be indium gallium nitride,

  • which would not only make the band gap easier to cross,

  • but also narrow it just the right amount

  • to bring its blue violet gap down to true blue.

  • This time, Akasaki and Amano didn't scoop Nakamura.

  • They were stuck trying to grow

  • indium gallium nitride in the first place.

  • Amano recalled, "It was generally said that gallium nitride

  • and indium nitride would not mix, like water and oil."

  • But Nakamura had an advantage,

  • his ability to customize his MOCVD reactor.

  • This allowed him to use brute force,

  • adjusting the reactor to pump as much indium

  • as he could onto the gallium nitride,

  • in the hopes that at least some would stick.

  • To his surprise, the technique worked,

  • giving him a clean indium gallium nitride crystal.

  • He quickly incorporated this active layer into his LED,

  • but the well worked a little too well

  • and overflowed with electrons,

  • leaking them back into the gallium nitride layers.

  • Unfazed, within a few months, Nakamura had fixed this too

  • by creating the opposite of a well, a hill.

  • He returned to his reactor one more time

  • to make aluminum gallium nitride,

  • a compound with a larger band gap that could block

  • electrons from escaping the well once inside.

  • (dramatic music)

  • The structure of the blue LED had become far more complex

  • than anyone could have imagined, but it was complete.

  • By 1992, Shūji Nakamura had this.

  • - And I showed the chairman, I told him,

  • "Please, hey chairman come to my office."

  • I showed him the blue LED

  • and he said, "ohh, this is great no?"

  • I became so happy.

  • I just became, out of my office, yeah.

  • - [Derek] After 30 years of searching

  • by countless scientists,

  • Nakamura had done it.

  • He had created a glorious, bright blue LED

  • that could even be seen in daylight.

  • It had a light output power of 1,500 microwatts

  • and emitted a perfect blue at exactly 450 nanometers.

  • It was over 100 times brighter

  • than the previous pseudo-blue LEDs on the market.

  • Nakamura wrote, "I felt like I had reached

  • the top of Mount Fuji."

  • Nichia called a press conference in Tokyo

  • to announce the world's first true blue LED.

  • The electronics industry was stunned.

  • A researcher from Toshiba remarked,

  • "Everyone was caught with their pants down."

  • The effect on Nichia's fortunes was immediate and explosive.

  • Orders flooded in,

  • and by the end of 1994,

  • they were manufacturing 1 million blue LEDs per month.

  • Within three years,

  • the company's revenue had nearly doubled.

  • In 1996, they made the jump from blue to white,

  • by placing a yellow phosphor over the LED.

  • This chemical absorbs the blue photons

  • and re-radiates them in a broad spectrum

  • across the visible range.

  • Soon enough, Nichia was selling the world's

  • first white LED.

  • At last, unlocking the final frontiers so many had doubted,

  • LED lighting.

  • Over the next four years, their sales doubled again.

  • By 2001, their revenue was approaching $700 million a year.

  • Over 60% came from blue LED products.

  • Today, Nichia is one of the largest LED manufacturers

  • in the world with an annual revenue in the billions.

  • As for Nakamura, to whom Nichia owed

  • the quadrupling of its fortunes?

  • (dramatic music)

  • - I increased my salary, $60,000.

  • After doubling, yeah.

  • - I heard you only got $170 bonus

  • - Each patent.

  • - So you got $170 bonus for the patent.

  • - Yes, yes.

  • - [Derek] This was all while the blue LED

  • was generating hundreds of millions of dollars in sales.

  • Eji Ogawa had always seen Nakamura's stubborn individuality

  • as a liability, not a strength.

  • The message was clear.

  • In 2000, after more than 20 years at Nichia,

  • Nakamura left the company for the US,

  • where job offers had been pouring in.

  • But his troubles with Nichia weren't over.

  • He began consulting for Cree, another LED company.

  • Nichia was furious and sued him for leaking company secrets.

  • Nakamura responded by counter-suing Nichia

  • for never properly compensating him for his invention,

  • seeking $20 million.

  • In 2001, the Japanese courts ruled with Nakamura

  • and ordered Nichia to pay him 10 times his initial request.

  • But Nichia appealed

  • and the case was eventually settled

  • with a payout of $8 million.

  • In the end, this was only enough

  • to cover Nakamura's legal fees.

  • (soft music)

  • This is all he got for an invention

  • that now comprises an $80 billion industry,

  • from house lights to streetlights.

  • While you watch this video on a phone, computer or TV.

  • If you're outside following traffic lights or displays,

  • chances are you are relying on blue LEDs.

  • We might even be getting too much of them.

  • You may have heard warnings to avoid blue light from screens

  • before bed because it can disrupt your circadian rhythm.

  • That all comes from the gallium nitride blue LED.

  • But as for lighting, there are virtually no downsides

  • to an LED bulb.

  • Compared to an incandescent or fluorescent bulb,

  • they are far more efficient.

  • They last many times longer, are safer to handle,

  • and are completely customizable.

  • 30 years after the first white LED,

  • high-end bulbs today

  • allow you to choose between 50,000

  • different shades of white.

  • Most importantly, their price has come down to only a couple

  • of dollars more than other types of bulbs.

  • And at their efficiency, with average daily use

  • and electricity pricing,

  • you can recoup that cost in only two months

  • and continue to save for years after that.

  • The result is a lighting revolution.

  • In 2010, just 1% of residential lighting sales

  • in the world were LED.

  • In 2022, it was over half.

  • Experts estimate that within the next 10 years,

  • nearly all lighting sales will be LED.

  • (soft music)

  • The energy savings will be enormous.

  • Lighting accounts for 5% of all carbon emissions.

  • A full switch to LEDs could save an estimated 1.4 billion

  • tons of CO2,

  • equivalent to taking almost half the cars

  • in the world off the road.

  • Today, Nakamura's research is on the next generation

  • of LEDs, micro LEDs, and UV LEDs.

  • - [Derek] So what are they making in there?

  • - LEDs, lasers, power devices.

  • This is one the best facility in the US.

  • - And this is because of you?

  • What's a standard LED size?

  • - [Shūji] 300 times 200 microns.

  • - [Derek] Okay.

  • - [Shūji] Smallest is five microns.

  • - [Derek] That is insanely tiny.

  • - So basically you can use that for like

  • near-eye display such as AR and VR.

  • - You could have like a retina display

  • that's like right up here?

  • - Yep.

  • - A human hair would be about that thick.

  • - [Shūji] Yep.

  • - And that's a really, really tiny LED.

  • UV LEDs could be used to sterilize surfaces like

  • in hospitals or kitchens.

  • Just flick on the UV lights

  • and pathogens would be dead in seconds.

  • - COVID-19, you know,

  • UV LED companies' stock prices were going,

  • skyrocketed because everyone expected to be

  • using these UV LEDS.

  • We can sterilize all the COVID-19, no?

  • For emitting diode, we use indium gallium nitride.

  • For UV, we use aluminum gallium nitride.

  • [Derek] Okay.

  • - [Shūji] 'Cause the band gap is much bigger.

  • - [Derek] Do you think this is what's coming?

  • - [Shūji] It's okay, it work, but the problem is the cost.

  • The efficiency is less than 10%.

  • The cost is very high.

  • But if the efficiency becomes more than 50%,

  • cost is almost comparable to the mercury lamp.

  • - [Derek] And you think it will happen, right?

  • Like the efficiency will go up?

  • - [Shūji] Yeah, yeah, I think so.

  • - It's just a matter of time.

  • - Yeah, I think so.

  • - [Derek] And he's even tackling one

  • of the biggest challenges of our time.

  • - [Shūji] I'm interested in physics.

  • - [Derek] Me too!

  • - I'm still interested in nuclear fusion.

  • So recently I started the company of nuclear fusion.

  • - Really?

  • - Oh yeah, last year.

  • - No way. - No way, aha.

  • (soft music)

  • - In 2014, Nakamura, Akasaki and Amano

  • were awarded the Nobel Prize in physics

  • for creating the blue LED.

  • Shortly afterwards, Nakamura publicly thanked Nichia

  • for supporting his work,

  • and he offered to visit and make amends,

  • but they turned down his offer

  • and today their relationship is still cold.

  • But perhaps even more important than the Nobel Prize,

  • By the time Nakamura released his blue LED in 1994,

  • he had published over 15 papers,

  • and he finally received his doctorate in engineering.

  • Today he has published over 900 papers.

  • Throughout his entire journey,

  • one thing has never changed.

  • What is your favorite color?

  • - Oh, blue.

  • - [Derek] Was it always blue?

  • Or only after you made the LED?

  • - I was born in a fishing village.

  • Fishing village.

  • In front of the house is awesome like, ocean.

  • Blue always.

  • - While I was learning about Nakamura's story,

  • I realized that what set him apart from the thousands

  • of researchers trying to unlock the blue LED,

  • it wasn't necessarily his knowledge,

  • but his determination, critical thinking,

  • and problem solving skills.

  • Where others saw dead ends,

  • he saw potential solutions.

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- LEDs don't get their color from their plastic covers.

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