My new patent on Gallium Nitride (GaN) blue LEDs. $6 billion market for white LEDs.
| | | | LED Bulb Market Share, Size, Research Report and Forecast (2020-2025) The global LED bulb market reached a value of nearly US$ 6 Billion in 2019. The market is further projected to r... | | | https://www.linkedin.com/pulse/how-do-you-make-new-gallium-nitride-blue-led-... How do you make a new Gallium Nitride blue LED? With isotopes. - Published on December 6, 2020 - Edit article - View stats Status is online jim bell CEO at Daltonium Isotopics. Better living through Isotopes.3 articles First, I would like to congratulate those who have been working on blue GaN blue LEDs for so long, in some cases neary 50 years, for their progress so far. These days, there is virtually no reason at all to buy a tungsten-filament incandescent bulb (at least of the common globular shape), and even compact-fluorescents (CFL's) are hard to justify. Ever since 2008, I have been considering isotopes, and how to use them to improve processes and devices. It's been a lonely task, because virtually every chemist or physicist views "isotopes" as merely atoms with a different number of neutrons, and thus a different atomic weight. Yes, they are indeed that, but they are so much more. I scan the literature, recently phys.org, to figure out how to modify the makeup of isotopes in ordinary-isotope materials to enhance characteristics and behaviors. Until a few weeks ago, I simply didn't realize how much trouble that the GaN blue LED industry was having doping crystalline GaN with magnesium to provide 'holes'. I should give credit where it is due: It was only a few weeks ago that I was reading the Quora.com system, and I saw that on October 1, 2015, a person named Karan Mehta had answered a question about "What was so difficult in making a blue LED?" https://www.quora.com/What-was-so-difficult-in-making-a-blue-LED I had long wondered how blue LEDs were made, but I wasn't really aware of how 'difficult' it was. My first exposure to 'blue LEDs' was in about 1985, when I had purchased a silicon carbide blue LED from Digi-Key, as I recall for $10. Nice color, not especially bright. The third paragraph of Mehta's answer said: "2)P-type doping: An LED uses a diode to inject charge carriers into quantum wells. A diode has a p-type material in contact with an n-type material. However, for a long time, no one could find a suitable p-type dopant for GaN. Nakamura managed to use magnesium as a p-type dopant by finding the right conditions (temperature and pressure). Even today, Mg doping is not ideal, due to the high activation energy. Only 10% of the Mg is activated. So, if your Mg concentration is 1e19, only about free 1e18 holes are generated. " Aha! I saw his statement that "Only 10% of the Mg is activated". I wasn't quite sure what "activated" meant, but I assumed that meant, "did the job". But THAT 'rang a bell', so to speak. I've long been aware that elemental (stable) magnesium isn't merely "magnesium". Magnesium in nature consists of 78.99% Mg-24 isotope, 11.01% Mg-26, and 10.00% Mg-25. https://www.webelements.com/magnesium/isotopes.html Moreover, I was well aware that it was only the Mg-25 isotope whose nucleus posses 'nuclear spin': Mg-24 and Mg-26 have both an even number of protons, and an even number of neutrons. But Mg-25 is different: its nucleus contains an odd (not even) number of neutrons, and so it has a slight 'wobble'. The unpaired neutron can be thought as orbiting around the positively-charged rest of the nucleus, so that rest of the nucleus behaves like a positive electric charge, itself spinning around the center-of-mass of the whole structure. And as every physicist should know (my degree is in Chemistry, from MIT), a charge travelling in a circle causes a magnetic dipole to exist.
From reading Mehta's description, I concluded that the problem is that not all of the magnesium 'worked'. I'll let you guess which one did. It seems fairly obvious to me.
Zinc, similarly, is made up of isotopes. https://www.webelements.com/zinc/isotopes.html Only 4.1% of natural, stable zinc is Zn-67 and it has a nuclear 'spin'. The rest is Zn-64, Zn-66, Zn-68, and Zn-70, and none of them have nuclear 'spin'. And I notice that some early work on GaN LEDs used Zinc as a p+ dopant. It worked, I suppose, but somehow it was abandoned early on, since magnesium worked better. Why? Could that be because 10% is greater than 4.1% ? Well, THAT can be fixed! Doing some more research, I also notice that the radius of gallium atoms is 130 picometers. https://www.webelements.com/gallium/index.html The radius of zinc atoms is 135 picometers. https://www.webelements.com/zinc/ And the radius of magnesium atoms is 150 picometers. https://www.webelements.com/magnesium/ So I can certainly understand the difficulty they had packing a 150 picometer-radius magnesium atom into a position for suitable for a 130 picometer gallium atom. They must have used a shoe-horn to pack the magnesium into the spot! Zinc's 135 picometers looks far more easily matched! Merry Christmas. And you're welcome! Jim Bell "I invent with isotopes". ===================[end of article]============================ https://www.nobelprize.org/uploads/2018/06/nakamura-lecture.pdf https://www.nobelprize.org/uploads/2018/06/akasaki-lecture.pdf https://www.bbc.com/news/science-environment-29518521#:~:text=The%202014%20N.... https://www.sciencedirect.com/science/article/pii/S0038110115001318#b0020 https://www.scientificamerican.com/article/blue-leds-fail-because-of-magnesi... https://www.quora.com/What-was-so-difficult-in-making-a-blue-LED https://www.gan.msm.cam.ac.uk/ LED Bulb Market Share, Size, Research Report and Forecast (2020-2025)
Yet another interesting potential application. How is the takeup on validation research, test runs, production methods, etc? Is isotope separation going to run into nuke centrifuge dual use issues? ie: How will bulk manufacturing of pure glass, silicon, etc be different...
On Sunday, December 6, 2020, 04:19:13 PM PST, grarpamp
Is isotope separation going to run into nuke centrifuge dual use issues? Zinc is currently centrifuged in relatively limited quantities for use as a corrosion-inhibitor for nuclear reactors. The problem is (was) that the lightest zinc isotope, Zn-64, reacts with a thermal neutron to form Zn-65, which emits dangerous gamma rays. So, decades ago they began separating out the Zn-64 from the other zinc isotopes. I think the market for this is about 2 tons per year. It's called "depleted zinc". ie: How will bulk manufacturing of pure glass, silicon, etc be different... These blue LEDs are made with gallium nitride crystals. The critical issue is the p+ (hole) doping, which has been done using magnesium atoms. The problem is that most magnesium atoms don't create a 'hole', but a few do. Similarly, Zinc does a weak job because only 4.1% of natural isotope zinc is Zn67. Most are other isotopes.
The big companies are Nichia, Osram, Samsung Electronics, and Everlight
Maybe non discretes, arrays... tvs and monitors too.
Zinc is currently centrifuged
Perhaps they won't prohibit various industrial separation methods if input isn't uranium :)
I think the market for this is about 2 tons per year.
https://en.wikipedia.org/w/index.php?search=isotope+separation https://en.wikipedia.org/wiki/Silicon_dioxide https://en.wikipedia.org/wiki/Single-mode_optical_fiber How amenable to known separation methods are all the elements you want to separate for uses? How cost effective separation... doping some junctions might not need much per year... but glass for fiber optic cables could be a lot of glass.
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Sunday, December 6, 2020 11:06 PM, jim bell
Ever since 2008, I have been considering isotopes, and how to use them to improve processes and devices. It's been a lonely task, because virtually every chemist or physicist views "isotopes" as merely atoms with a different number of neutrons, and thus a different atomic weight. Yes, they are indeed that, but they are so much more.
...
I've long been aware that elemental (stable) magnesium isn't merely "magnesium". Magnesium in nature consists of 78.99% Mg-24 isotope, 11.01% Mg-26, and 10.00% Mg-25. https://www.webelements.com/magnesium/isotopes.html
Moreover, I was well aware that it was only the Mg-25 isotope whose nucleus posses 'nuclear spin': Mg-24 and Mg-26 have both an even number of protons, and an even number of neutrons. But Mg-25 is different: its nucleus contains an odd (not even) number of neutrons, and so it has a slight 'wobble'. The unpaired neutron can be thought as orbiting around the positively-charged rest of the nucleus, so that rest of the nucleus behaves like a positive electric charge, itself spinning around the center-of-mass of the whole structure. And as every physicist should know (my degree is in Chemistry, from MIT), a charge travelling in a circle causes a magnetic dipole to exist.
From reading Mehta's description, I concluded that the problem is that not all of the magnesium 'worked'. I'll let you guess which one did. It seems fairly obvious to me.
Zinc, similarly, is made up of isotopes. https://www.webelements.com/zinc/isotopes.html Only 4.1% of natural, stable zinc is Zn-67 and it has a nuclear 'spin'. The rest is Zn-64, Zn-66, Zn-68, and Zn-70, and none of them have nuclear 'spin'. And I notice that some early work on GaN LEDs used Zinc as a p+ dopant. It worked, I suppose, but somehow it was abandoned early on, since magnesium worked better. Why? Could that be because 10% is greater than 4.1% ? Well, THAT can be fixed!
Doing some more research, I also notice that the radius of gallium atoms is 130 picometers. https://www.webelements.com/gallium/index.html The radius of zinc atoms is 135 picometers. https://www.webelements.com/zinc/ And the radius of magnesium atoms is 150 picometers. https://www.webelements.com/magnesium/ So I can certainly understand the difficulty they had packing a 150 picometer-radius magnesium atom into a position for suitable for a 130 picometer gallium atom. They must have used a shoe-horn to pack the magnesium into the spot! Zinc's 135 picometers looks far more easily matched!
Merry Christmas. And you're welcome!
Jim, it would be interesting to focus on isotope separation techniques. i get the impression that lack of affordable options precludes the use of enriched elements in most manufacturing. have you given this aspect consideration? best regards,
On Monday, December 7, 2020, 11:15:28 AM PST, coderman
Jim, it would be interesting to focus on isotope separation techniques. i get the impression that lack of affordable options precludes the use of enriched elements in most manufacturing.
By far the cheapest method of separating isotopes involves the gas centrifuge. But in order to employ the gas centrifuge, it is necessary to find a compound containing the target element that is reasonably stable and volatile, and hopefully well-behaved. Zinc can be separated by Gas Centrifuge: I think one compound is dimethyl zinc. Although, if you actually saw dimethyl zinc you wouldn't label it "well-behaved"! In air, it's not only flammable, it's also self-igniting! (This video is actually diETHYL zinc, but it behaves similarly!) https://www.youtube.com/watch?v=99wPiMb-k0o At 2:15 Wow! Fortunately, gas centrifuges are nicely-sealed systems. And, there is a huge excess of otherwise-unused gas centrifuge capacity in the world. Why? They built them to separate uranium isotopes, and when you've separated all the uranium you need, they don't (currently) have anything to do with them. So, when the need for separated isotopes explodes, some day, there will be no lack of gas centrifuges to make them. This shows separation of Silicon Tetrafluoride using a column distillation system. https://www.tandfonline.com/doi/abs/10.1080/01496399008050336 In this one, a method is described to exchange silicon isotopes using exchange. https://www.freepatentsonline.com/y2009/0136407.html The 'worst' (costliest) way to do separations is by the Calutron, https://www.youtube.com/watch?v=HC8LUTisqPQ which can be thought of as a huge mass-spectrometer that has 'buckets' that collect the isotopes that get deflected by the magnetic fields. A few years ago, I was quoted a price of about $17,000 per gram for Hf-177 and just about the same price for Hf-179. A few years ago, I wondered if it was possible to do Hafnium isotope separation using a gas centrifuge. I found a reference to a study in Russia where they used a Hafnium isotope (Maybe it was Hf-174?), still mixed with other Hafnium isotopes, to study its radioactive decay. They used a relatively large amount of Hafnium, maybe a kilogram, which was said to have been separated from zirconium years ago (in the Soviet Union era). The researcher who is currently using that Hafnium said that they really didn't know how or why this particular element, hafnium, was separated. This was NOT an isotopic separation, just a separation of two elements of rather large mass-difference. But it tells me that it is possible do form a gaseous compound containing hafnium that can be centrifuged. The reason they don't do that, yet, is presumably because the demand for Hafnium isotopes is (so far) quite miniscule. I calculated that it would take about a milligram of hafnium to cover a 300 millimeter silicon wafer with 2 nanometers of a hafnium dielectric. (Assuming no wastage.) Or, $17 per wafer, which I think the industry will find economical. Thus: https://www.linkedin.com/pulse/much-better-than-hafnium-zirconium-higher-die...
have you given this aspect consideration?
Extensively! Repeatedly! Over and over again! I have understood, for well over 11 years, that the main limitation to isotope inventions is there it is necessary to get more than the cost of the isotopes separated in order to make an isotopic invention 'work'. Fortunately, as of now I have figured out many dozens of separate isotopic inventions that will probably provide more such benefit than the costs involved. Jim Bell
participants (3)
-
coderman -
grarpamp -
jim bell