Will gallium nitride electronics change the world? | Upscaled

silicon is over where is it probably not but there is some exciting check out there that may change or devices all the way from laptops to electric cars welcome to upskilled our explainer show where we try to dig into the tech that makes your gadgets better in our last episode we took a look at how much CPUs matter for gaming performance and a couple of you commented that you wish we've measured the slowest 1% of frames this can help determine how smooth the gameplay footage actually is and we probably should have but the eagle-eyed among you may have noticed that the Gears of War benchmark at least recorded the slowest 5% frame time and comparing our high-end and low-end CPU we saw and still pretty much no difference at all still we'll try to run our own tests next time today we're gonna tackle something that was actually one of the very first ideas we ever had for upscale most electronics these days are based on silicon but we're starting to see some circuits that incorporate gallium nitride a material that some folks are saying will lead us to a whole new world of post silicon computing so what is gallium nitride what is it actually good for and what does the future of transistors actually look like gallium itself is a silvery metal probably most famous for melting at about 85 degrees Fahrenheit or say in the palm of your hand you might have come across gallium in high-performance thermal compounds like conduct anot but in its pure form it's not terribly useful what with that whole melting at such a low temperature thing however gallium forms a number of interesting compounds gallium arsenide has been used as a semiconductor for decades Cray actually tried to build a supercomputer with gallium arsenide processors in the late 80s and I've been working for about five years now on Cray 3 project so the create three computer is a combination of gallium arsenite for the logic and silicon for memory and your cell phone probably has more than a few gallium arsenide parts working as radio amplifiers gallium nitride is a little later to the party this is gallium bonded to nitrogen gas and in its natural state it forms sort of a hard yellowish crystal but even before we get to what it might be used for in the future gallium nitride has actually already changed the world in 1993 Shuji Nakamura building on work done by isamu akasaki and hiroshi amano used gallium nitride to build the world's first blue light LED this alone led to the blue ray arguably technologies most important innovation ever but blue LEDs also when mixed with maybe a little indium and a yellow phosphor led to the white LED today almost all the LEDs used for indoor lighting in addition to the LEDs in say flat panel displays are based on gallium nitride but these days gallium nitride or Gann has been getting a lot of hype for how it might improve power delivery wireless communication and maybe even processing for services like silicon gallium nitride is a semiconductor now in a true conductor like say copper the outermost electrons called the valence electrons are sort of loosely attached and they can kind of flow freely through the metal carrying electric current in an insulator like plastic it's the opposite the electrons are tightly bound and no current can flow the valence electrons in a semiconductor are just kind of lazy by default they won't move but give them a little energy say by applying some heat or some voltage and it will turn into a conductor and let electricity flow the added energy boosts those electrons from that valence band up into the conduction band where they can move around this property is the basis for transistors they act sort of like a valve or switch for electricity apply some voltage and the transistor opens up and lets electricity flow through it remove that voltage and the valve closes blocking the current take a bunch of these transistors arrange them into logic gates and you've got yourself a pocket calculator gallium nitride is interesting because it's bad gap the amount of energy needed to kick those electrons from the valence band up to the conduction band is about three times larger than silicones this means technically it's harder to get it to switch over from being in insulator to a conductor but that actually has some benefits for one gallium nitride can operate it far higher temperatures most computers try to keep their chips at a hundred degrees C or below two it's above that and the energy from the heat can actually start flipping transistors on and random causing glitches or even damaging the chip gand transistors can operate at up to 300 degrees C or maybe even higher dan also has a significantly higher breakdown voltage than silicon this is the voltage where a transistor just can't block the flow of electricity anymore it breaks through the valve and can't stop the current from flowing with gaen you can potentially make a chip the same size as a silicon one that can handle much larger voltage or you can just make a much smaller chip dan also has very low resistance to current flowing through it so it produces very little waste heat and as a transistor it has a very fast switching speed between on and off and all of this makes again extremely well-suited to so-called power electronics for more info I spoke to Ben Liu in MIT PhD and co-founder of Cambridge electronics a company trying to build super high efficiency gann based power electronics this field encompasses everything from the AC inverters that let a rooftop solar system connect to the power grid to the circuits that deal with the batteries and electric cars down to your laptop and phone chargers for example of how much power conversion there can be in one device in a typical desktop computer the power supply is taking the feed from the wall and converting it into a 12 volt a 5 volt and a 3.3 volt connection and from there additional circuits in the motherboard are converting the power down to say maybe the 1.2 volts the processor needs 0.8 volts for the GPU and 1.3 volts for the RAM in modern devices this is all accomplished with switching power supplies these circuits reduce wall power 120 volts in the u.s. 220 or 240 in the rest of the world down to these say nine volts a basic phone charger uses by means of transistor based switches to wildly simplify if these switches are letting power through five percent of the time then the switch and power supply delivers five percent of the voltage now in reality this also relies on capacitors and maybe rectifiers and inductors and a bunch of other bits but that's the basic idea a super high-end PC power supply might only waste five percent of the power it converts but most switching power supplies waste 15 to 20 percent and that's still considered very efficient Liu said that from a purely physics perspective we're already approaching silicon's maximum potential limit but the gallium nitride may theoretically be a thousand times more efficient than silicon enabling much smaller charging devices that hardly waste any power this is a 30 watt gallium nitride anchor charger compared to a 30 watt silicon charger but honestly they don't seem that much smaller Liu says that this is such a new field we are only starting to tap into gallium nitride potential these current devices might only be four or five times as efficient as silicon and we're only seeing part of the circuitry replaced with gallium nitride the long-term goal to get us to nearly lossless power conversion is to replace the entire charging circuitry with high performance gallium nitride parts gallium nitride power electronics could mean that the entire circuitry contained in say a laptops charging brick could be built just into the plug itself or on many smaller devices the power conversion circuitry could just be built into the device eliminating the nest of dongles that comes with owning modern gadgets you also pointed out that servers and data centers currently consume about 3% of the world's power and more efficient circuitry there could have a huge impact on global power usage since gallium nitride circuitry also produces less heat it could potentially make data centres easier to cool another source of energy savings gallium nitride inverters could make solar cells cheaper lighter which could let them be installed in more places do you think we can pack in this little box the power of this 2 kilowatt inverter well our engineers did it and they can even boost range and electric cars by improving efficiency heck they could even make electric high-speed rail easier to deploy in fact the Tesla Model 3 already uses silicon carbide a material with similar properties to gallium nitride in some of its power circuitry if Moore's law has seen processing power double about every two years for the past few decades power electronics according to Lou have been on more of a 10-year cycle still improving just not nearly as fast as the rest of electronics and gallium nitride might be a material that helps change that gallium nitride is fast switching speed efficiency and ability to handle high temperatures and voltages are actually seeing it already used in another field we've extensively covered 5g gallium nitride has already been used in LTE base stations in amplification circuitry gallium nitride can efficiently produce high frequency high power signals and because of that it will almost certainly find its way into the small cell base stations we're expecting with 5g and with the power draw of 5g antennas in phones also a concern gallium nitride may provide a solution to boost battery life in handsets - so through all this research I kept wondering what's keeping gallium nitride from replacing the silicon in processors as well it sounds so much better it switches faster it's more power efficient you can make smaller chips with it it operates at higher frequencies why did we get stuck with silicon when this stuff was out there all along well one challenge is that for a long time the only transistors we could make with this stuff we're so-called depletion mode transistors which means they're actually åland by default it takes voltage applied to them to turn them off for building logic circuits this style of transistor is actually much harder to work with but several researchers including bin lew have actually been able to do this online so-called enhancement mode transistors that are off by default we called up another those researchers Yuji Joe is a former student of Nakamura's and an assistant professor of electrical computer and energy engineering at ASU Jai was part of a team that received a NASA grant to design a gallium nitride processor for use in extreme environments and so far he's been able to design some simple Gantt circuits that can operate at up to 500 degrees C or 900 degrees Fahrenheit the hope is to build an actual gallium nitride microprocessor that could be used to power a Lander that NASA hopes to one day drop on Venus or somewhere else horrific ly hot in the solar system AG and processor built to the same specifications as a current CPU would be several times faster than a silicon device we're talking maybe 10 up to a hundred gigahertz and way more energy-efficient the problem is we are nowhere close to being able to build one compared to silicon gallium nitride is just much harder to work with silicon is relatively easy to process into giant crystals that we can slice up into wafers and used to make chips and by relatively easy I mean it's insanely complicated but there's plenty of silicon around and we've worked out how to do this and it does make high quality crystals and by contrast is messy according to UC Santa Barbara's Materials Department where blue light pioneer Shuji Nakamura now teaches before the year 2000 no one had been able to develop a gam crystal with less than a billion defects per square centimeter these defects where the crystal structure is either missing an atom or has an extra one inserted can degrade performance or even cause manufacturing errors current gained manufacturing can achieve under a hundred thousand defects per square centimeter but by contrast high grade silicon typically has under a hundred part of the problem is we're just still not great at producing gallium nitride the current process grows a thin layer of gallium nitride on top of a silicon wafer a process called epitaxy now this lets the wafer be processed in a normal chip fab but ideally we'd love to grow high quality wafers of pure gallium nitride we'd probably have to design and build a whole new type of chip fab and considering how insanely complicated and expensive they are this is gonna take some serious investment also the gaen transistors that Joe is currently building do work perfectly fine to form basic logic gates but they're on the micrometer scale so we're talking between one and 10 thousand times larger than current silicon transistors there is just no way we are cramming a billion plus of those on a chip the size of a postage stamp manufacturing and design will improve but it'll take time the first silicon electronics were built in 1906 today's processors have more than a hundred years of research and hundreds of billions of dollars invested in them John pointed to the blue light LED is another example gallium nitride made white LEDs possible in 1993 but LED lighting really became a thing what like three years ago it's possible that with enough time gallium nitride may replace silicon in processors but it's just as likely it'll take so long that will have a massive paradigm shift in how computers even worked before then there's always quantum computing on the horizon and Gauss lab is actually also working on optoelectronics and photonics which is to say building chips that actually use photons to carry information instead of electricity and one of the prime candidates for generating those photons gallium nitride for nowt we can look forward to a future with less wasted electricity and maybe if we're lucky the end of the laptop power brick and let us know if there's any other topics you want us to dig into this one took a ton of research we're including these sources in the description for the first time and it led me a lot of different directions we're cooking around some story ideas for battery technology or maybe transistor design and as always be sure to LIKE and subscribe and we'll catch you next time [Music] [Music]

Channel: Engadget

Views: 407,745

Keywords: engadget, technology, consumer tech, gadgets, science, gear, tech, Upscaled, Gallium Nitride, GaN, power, chargers, 5G, processor, nasa, venus, space, future, transistor, electrons, atoms, band gap

Id: sfTXZP2DB20

Length: 14min 29sec (869 seconds)

Published: Thu Jul 02 2020