How do laboratories make their own diamonds

How to become a diamond maker - a podcast with Stefan Gsell

How to become a diamond maker - a podcast with Stefan Gsell

Years of research have rewarded the physicist Stefan Gsell: with the perfect recipe for artificially produced, single-crystal diamonds. In the podcast he talks about his start-up that turned a laboratory into an inexhaustible diamond mine.
Copyright: BMBF

Welcome to the BMBF Podcast, the podcast from the Federal Ministry of Education and Research. I'm talking to Stefan Gsell today, he is a researcher and CEO of Augsburg Diamond Technology GmbH (audiatec), which specializes in the synthesis of diamond single crystals. Using its own innovative technology, audiatec produces the world's largest single-crystal diamond discs. Welcome, Mr. Gsell.

Good day.

I look forward to hearing more about your research and your start-up today. And what ups and downs there may have been when founding auditec and which you have mastered. With continuous research, they have developed a technique that produces diamonds larger than those owned by the Queen of England. Even though I've heard that comparing it to jewelery diamonds is difficult. How did you come up with the idea of ​​making diamonds yourself?

I have to say right away: in terms of area, it is larger than the Queen's largest diamonds. That is always very important, because otherwise people here in Augsburg think that incredible gemstones are being made of incredible value, so only the largest in terms of area. How did it come about? So for me it started quite normally. I looked around for an internship at the University of Augsburg, where I studied physics, and then I turned to Dr. Shocked. That was in 2000 and that's where I did my first internship. And then I was fascinated by the subject of diamonds. Even if at that time we in this group only produced the thinnest layers of diamond that could not be picked up. And of course the team was right at the time and so it went on, with my thesis, then the doctoral thesis, then the postdoc. So I've been working on the topic continuously since 2000. A prerequisite was, of course, that there was always funding, including the project at the end of this stage, but also before that. These are the typical third-party funded projects, just like you have the opportunity at a university to collect them and get them approved successfully. One reason was certainly that the subject of diamonds is of course quite catchy and also seemed attractive to those who approved the applications.

That sounds exciting. How big is the largest stone produced so far?

It has a diameter of 92 millimeters and a thickness of three to five millimeters. Because you have to say that it is not homogeneously thick. This is due to the growth process. And if you put that on the scales, the equivalent of 155 carats comes out, because one carat is equal to 0.2 grams, which means that carats are a weight and it is a disc that you can pick up. Free-standing, where many people are of course surprised that it is diamond.

Can you compare the size to anything you know?

If you were to take something out of everyday life, you would say a coffee saucer.

Okay, you can imagine that; I understand. And maybe even reveal what it is worth?

Yes, there comes the famous saying: It is worth as much as someone is willing to pay. We didn't put a price tag on it. And we don't sell such large panes either; our customers typically need tailor-made, smaller stones, around thirty by thirty millimeters in edge length. That means we always cut something out of these larger pieces. That means that a lot of people work for us, although we don't have that many people now, but five or six people just work in post-processing. When the diamond is already made, to qualify it. Which areas are free of defects, so to speak, and then we work with the desired geometries according to customer requirements. It is cut out and prepared accordingly.

What do your customers need these diamond discs for?

Customers often need diamond pieces in their sector of mechanical processing of materials. Sure, diamond is very hard. This is of course a good idea. What is now also possible with this monocrystalline diamond is to produce a cutting edge that is unsurpassed in terms of quality. This means that if you look at the cutting edge with the microscope at a magnification of one hundred thousand times, you will not see any breakouts. There you see a very nice, straight cutting edge. And these cutting edges are used again, for example, to manufacture glasses or contact lenses or any watch parts that have to be very shiny. So with these diamonds you have the possibility to produce cutting tools that allow a shine processing, where you have previously z. B. could only polish. With diamond paste z. B. processed glasses. But with diamond tools made from our stones you don't have to do anything afterwards and there is a relatively large market for glasses and lenses. Another market is diamond windows. The point is that you have some kind of reactive chamber where something highly active is happening and only diamond is chemically stable so that you can see through, but the window still remains stable and is not attacked. So we always deliver the raw material. Our customers are B. People who make cutting tools or who make such windows. This requires very special polishing skills. For them we are simply a diamond mine, so to speak; the Augsburg diamond mine, which is inexhaustible as long as there is methane, hydrogen and electricity. We then sell the prefabricated rough stones.

I am now interested in a little more detail: What is the recipe for the diamonds and how does the process work, explained in a very simple way?

So there are basically two methods of making diamonds in the laboratory. One method is to try to reproduce what happens in the earth's crust. That means you work with high pressure and high temperature; this was discovered as early as 1953 and is an established procedure. We do the other procedure. It's about having a gas phase. That is why the process is also called a CVD process, Chemical Vapor Disposition. And from this gas phase one brings carbon carrier gases, e.g. methane in our case. And they have to split this methane into its components, so that a reactive gas species is created. And this reactive gas species then buzzes in this reaction chamber at around 2,000 to 3,000 degrees Celsius, because there is a plasma around and, if everything is well coordinated, it can be deposited on a surface as diamond, as monocrystalline diamond. And the special thing about the Augsburg diamond technology is that we do not put another already grown or natural diamond in our chamber as a substrate and only continue the diamond at one height, but that we put a non-diamond substrate in our chamber . And so we can achieve such a large area of ​​92 millimeters or 100 millimeters. This means that we ultimately place a silicon substrate with two thin so-called buffer layers in the chamber and on the full 100 millimeter layer by layer this carbon is deposited as diamond and so the diamond layer grows upwards, nanometer by nanometer. And that's what's special about us: That you use a non-diamond substrate. Only when it comes to diamonds are we the first to achieve this, that it really works on a large scale.

And how long does this chemical gas phase separation take in the reactor?

So you can calculate that you will need about three to four days for one millimeter. That is a relatively long time when everything has to run stably, and unfortunately the power consumption is quite high to generate the plasma. But there is no avoiding it. You have to create this reactive gas phase so that the methane is split off from the carbon and the carbon atoms can be deposited layer by layer on the surface. But they can say three to four days for a millimeter.

And if you compare nature to this - how long does it take nature to produce diamonds?

One speculates between 80 days to several thousand years, depending on what conditions prevailed in the earth's crust. The point is, of course, that physicists would call the phase diagram here, which exact pressure and temperature conditions prevailed and there was also enough carbon in the environment, which then becomes one under these high pressure and temperature conditions Could diamond join together? So of course it takes a lot longer and of course you have to say that you can't dictate anything to nature. “Wax a disc with 1.1 or 1.3 millimeters” does not work there. What comes out of the mine comes out of it.

Can you still say that your production is sustainable in the end because there are incalculable conditions in nature as to when and how many diamonds are obtained?

So there are many studies and there are of course the followers, especially those of the advocates of natural diamonds, who earn billions with jewelry, from natural diamonds, who of course criticize this green paint of these labgrown diamonds. This is the established name, so to speak: laboratory-grown diamonds, not artificial diamonds, but lab-grown diamonds. But that's not it at all. What matters is what is reproducible. And our customers, who have no choice but to use a diamond as a raw material for their industrial applications. No other material allows these applications to be carried out. And I am convinced that it is greener than when you mine natural diamonds with all the consequences for nature: I have to wash them out, use chemicals, drill huge holes. But the decisive factor is of course also for an industrial product - it should still be available in ten years; at an acceptable price. And with the natural diamond mines it is actually the same as with the peak oil. The peak has already been passed in oil deposits and it is becoming increasingly difficult to explore or find new deposits. And the existing diamond mines are already approaching their lifetimes relatively quickly. And as I said: a natural diamond has different growth forms. There are super pure ones, but there are also risks of what can come out of the mine. Our diamonds or those from other manufacturers are simply created under controlled laboratory conditions. And of course that is necessary for an industrial product.

Her long-term research has now turned into a start-up. I would be interested to know what experiences you had when founding audiatec and what advice you would give to people who might also be thinking about founding a company?

So we were lucky after this great VIP project from the BMBF, which made it possible for us to get close to a prototype that the Federal Ministry of Economics also approved the EXIST research transfer project. It made the transition from pure university research to this spin-off very easy for us, because our technology is quite investment-intensive due to the systems and processes used. And here you have to say that the EXIST project was really a milestone. Also the exchange with other founders in the start-up phase. What I would advise is: So a very big point for a spin-off to be successful is the team. You hear that over and over again, but we also noticed that; not within the team. That was all okay. But also with the exchange of ideas and especially the structure of the society. So you have to think carefully at the beginning: Who is really there? Because it's like a wedding. But then it is very difficult to say in private life, like in a divorce, “I no longer want him as a partner, he no longer performs at all, he no longer makes an effort!” This circle of society is very important. And we were lucky that we had a soft start via the EXIST program and that we were also able to rent equipment from the University of Augsburg at the beginning, so that we did not need an investor. But of course the search for investors is also a very important point at the beginning if you need outside capital here. And especially when you come from science, it is relatively far from knowing the right language. And then it is good to have someone on hand, either a coach or directly in the team, preferably yourself, who has experience from the business plan to the point where you have to face investors. This is very, very helpful and very important in order to be taken seriously by a counterpart who is supposed to give you a few 100,000 euros. So the team, the people in the team and also very important: Be realistic. Sometimes you fall into the delusion that what you do yourself is the most important thing in the world. And that it will be ripped out of your hand like hotcakes. Since taking a step back every now and then and saying: “Okay, is there a competition? Is there simply a solution with others that may already be there, that is more established, that is just as good? Am i really better Do I have this USP, this Unique Selling Point, so that I can survive here in the market?

You mentioned two support measures. One is the VIP project from the BMBF. How exactly did that help you?

That helped us to the extent that we initially had a security and at that time we were missing some building blocks to demonstrate production technology, yes, it is possible to produce this single-crystal diamond on this large area. And here these investments in the six-figure range were only possible through the VIP project. The personnel funds secured for three years also helped. Because you just need time to validate something, to think in different directions and sometimes to recognize a dead end. And still have the time to go in the other direction and to be able to make this investment at all. Of course, this enabled the university to raise the investment.

It is often a long way from an idea to innovation and from there to marketing. You have walked that too. What motivates you to keep going even if you have difficulties or setbacks? Were there lows during this time?

Well, I have to say, luckily it has been pretty smooth since the spin-off in 2015. I couldn't name any particular depths. If, for example, a new innovation step is taken, i.e. more new customers are gained within the spin-off. Then you need a team that is ready to work beyond the average, beyond the eight-hour day, until you have consolidated yourself in the market and you take on new employees. In other words, it was always a problem in those phases where you could tear yourself apart, but where you were naturally positive because you won new customers who suddenly had twice as much demand. That said, it's positive stress. You knew okay, we need two people now, but you can't conjure them up. But in that time we have to absorb that. That was positive stress. But I wouldn't call it a low at all.

Or what if you now say the leap from science to entrepreneurship, maybe also such a small climax, such a moment of success that you have been dragging from for a long time?

We always took that very pragmatically. Every customer we have won who said kkay, you are better than the previous one, is a success. That totally gave us a boost because we knew we were on the right track. And of course those points where we have continued to optimize our processes. When we have succeeded in making larger areas contiguous, not just reaching 92 millimeters once, but simply reaching these areas consistently. Of course, that was always a highlight. We were happy internally because we knew that this would make us more productive and that we were always measured by price. We are in competition, especially with Asian companies, and also with North American companies. And there they are always measured by the price. And no matter how friendly the customer has been over the past few years. If he comes up and says, “I've got one that is at least as good as half as expensive”, then you lose such a customer. Our heights are: Every customer that we have won who shows us that our material is something special, because most of them came from the natural diamond, that our material can establish itself on the market.

What are the next plans for your start-up now?

We are continuing with the expansion of the plant park and more and more away from mechanical applications. So that the mechanical applications provide the basic framework, but we also come specifically to applications in the jewelry area. So we're already delivering more records.The other diamond manufacturers grow jewelry diamonds on it is a very, very big market. And bringing our material to the point where our panels can serve as a substrate for others is a goal. We are now quite far in the process. These are the next steps and it is always about simply expanding the system capacity. We have to make the raw material as good as possible. We need others who then put the applications on top. So we don't make diamond quantum computers ourselves, which is such a hot topic at the moment, or diamond electronics. We always see ourselves as a raw material supplier.

My penultimate question: what would you advise young researchers to do today?

Perseverance is a very important point. When you are convinced that you can be successful here. I'm talking about the point of view that the ultimate goal is a spin-off, that is, commercialization. If I'm a researcher doing a PhD, the main goal is: “Get it done in three or four years and have fun”. But if your goal is to commercialize something, perseverance is a very important point. But to keep asking critical questions. And you can do that at the university. We did that too. Does the market even need what I'm researching, what I'm developing? And when you get closer to some kind of spin-off, coordinate with other people who have already gone through this process, call. We did that too. We then received a list of best practice examples via the EXIST project, for example, and we called them and they were all open because they themselves were in the situation three, four, five years ago Foundation to stand. And there we received a lot of valuable tips. That means don't put the sand in your head. But neither do you think you are the smartest and you can do everything. Especially when it comes to a spin-off, join forces with others!

That definitely sounds like a good recipe. One small question interests me at the end. Did you keep your first diamond that was made to be touchable?

We still kept it. But you have to know: that was a thin layer of platelets. And it might not be sellable anyway because it had too many defects. But we still have that

Thank you, Mr Gsell, for this exciting conversation. I learned a lot about diamonds and the diamond smithy that they set up in Augsburg. Thanks for that. I think that this can also be an inspiration for many, perhaps pursuing an idea from their studies and turning it into an innovative business idea. Thank you for the interview and dear listeners: We look forward to hearing from you again next time for the BMBF podcast. Thank you, Mr Gsell.

Yes, please. Listen again.