The Materials Universe Podcast: Episode 1

[00:00:00] Abbey Stanzione: Welcome to the Materials Universe podcast, a podcast where we will explore the world of materials science and how it shapes our lives. My name is Abby Stanzione and I will be your host this season. Join me as I interview researchers from the Center for Dynamics and Control of Materials at UT Austin.

Hello and welcome. You’re listening to the Materials Universe podcast. I’m your host, Abby Stanzione. Today with me, I have Dr. Edward Yu, who is the director for the Center for Dynamics and Control of Materials, as well as a professor in electrical and computer engineering at the University of Texas at Austin.

Welcome Dr. Yu. Thank you

[00:00:39] Edward Yu: very much, Abby.

[00:00:40] Abbey Stanzione: So tell me a little bit about who you are and what your area of research is here at UT Austin.

[00:00:46] Edward Yu: Sure. So, so as you mentioned earlier, I’m a professor of electrical and computer engineering, uh, here at the University of Texas at Austin. And, uh, my research lab, uh, and much of my teaching involves really trying to understand the properties of mostly semiconductor materials, but, uh, more broadly.

materials when you scale them down to very small sizes, right? So how you do that, how you create very small material structures, what their interesting properties are, and how you can use those properties in different types of, uh, electronic or photonic. Photonic meaning Uh, you know, having to do with light, uh, applications, so, uh, that includes things like how do we make better transistors, meaning transistors, for example, that can operate at higher power or consume, uh, less power, um, how do we make more efficient solar cells or use the basic technology, uh, behind solar cells to make other types of devices that are relevant to renewable and sustainable energy.

And, uh, what are tools that we can develop and use to really understand the properties of materials at, uh, at the nanoscale?

[00:02:06] Abbey Stanzione: So just for our listeners out there, I’d like to talk a little more about what a semiconductor is and what a transistor is. A semiconductor is a material that can switch between conducting electricity, like copper and wires, or it can switch to acting like an insulator, such as glass or the plastic around the wires that keeps you from getting shocked.

Many semiconductors, like silicon, can switch to their conductive state when a small voltage is applied and switch to their non conductive state when that voltage is removed. So a transistor is a semiconductor device that regulates current or voltage flow and acts as a switch for signals, but without actually having any moving parts or needing a human to control it.

You can think of a transistor kind of like a dam. Under certain conditions, you may want the dam to let water flow through it. In other situations, you may want the dam to prevent water from moving through. A transistor does the same thing, except instead of water, it allows, or it prevents electricity from flowing through it.

So, in its most basic form, a transistor is the most basic kind of switch, where applying a voltage to the transistor may turn it on and allow current to flow, or removing the voltage to turn it off and stopping the current. The power of transistors is that they can be combined to make what are called logic gates, and that transistors switch on and off super fast.

The ability for electronic circuitry to be able to process logic so quickly is what enables creating complex things like computers, which can process millions of inputs every second. The ability for engineers and scientists to make transistors smaller and faster is really what has allowed the rapid growth of life changing technologies in the last few decades.

For example, the first computer made in 1954 used 700 transistors that were each a centimeter long. Obviously, that can’t stream 4K video, so to process all the new information and data we have now, transistors need to get smaller and faster. Now modern laptops have over 10 billion transistors in them. In a kind of ridiculous example, if transistors were still the same size as they were in the 1950s, and you wanted the same computing power as a modern laptop, your laptop would have to be about two and a half acres in size.

So though you may not. Transistors are used everywhere in our everyday lives. They’re in your phone, your computer, your headphones, your cars, microwave, watches. Essentially every piece of technology has transistors in it today. So Dr. Yu, you’ve explained what you do here at UT, but how did you get to be here researching semiconductors?

[00:04:42] Edward Yu: My education is actually mostly in physics, uh, so my undergraduate and graduate degrees are in physics and applied physics, respectively. And, you know, my thinking at that time was that I, you know, as I was, when I was a student, and still now, uh, I really did and continue to love physics. And… I know it sounds like a very geeky thing to say, but, uh, you know, this is how many of us as professors, uh, often are.

And, as I was thinking about, uh, various possibilities for graduate school, I, I sort of realized that, uh, you know, while, uh, I loved physics, And I continue to think that the pursuit of knowledge for its own sake is, is a tremendously important and noble undertaking. Uh, what I wanted to do, uh, in my own career was slightly different.

I wanted to do something that, uh, would have more tangible benefits to society, right? Beyond, uh, simply the pursuit of, of knowledge. And so I moved into what’s called applied physics, which really is, uh, looking at questions in physics as a science, but questions that are motivated by ultimately some technological application.

How do you make a better transistor or a better LED or something like that? And, uh, so then over the years, that, uh, has led me to electrical engineering, and material science. And I have been pursuing those fields, uh, as a professor for now just over 30 years.

[00:06:30] Abbey Stanzione: What a circuitous route to get you to UT today.

It’s cool that you get to work in a job that allows you to continue your love for physics and for learning and helps with your desire to contribute to society. Since you brought it up, I’d like to take a minute here to talk about what material science is and what electrical engineering is and, you know, the differences between them.

Material science is an interdisciplinary field, meaning that it spans multiple subjects of study. And it focuses on the investigation of the relationships between the structures and the properties of materials, as well as the design and development of new materials. People who study material science could go on to work in various industries like aerospace, automotive, biomedical, energy, or electronics.

On the other hand, electrical engineering is a broad field that deals with the study and application of electricity, electronics, and electromagnetism. People in this field could work in telecommunications, power generation, transportation, and manufacturing. Both of these fields utilize semiconductors, and so I was wondering if you could explain a little bit about the history and how they became so useful to the U.

S. and, you know, to the

[00:07:38] Edward Yu: world. Yes, absolutely. So semiconductors actually have been studied as materials for quite a long time. Uh, some of their basic properties were being studied by scientists even back in the 1800s. But the understanding of those properties of semiconductors was much more rudimentary.

time. Uh, what really brought semiconductors to the fore in terms of technologies, uh, that are in use today was really a series of developments in the mid 20th century. And in the most well known among these was the invention of the transistor, uh, at Bell Laboratories, uh, which was in the late 19. I think 1947, uh, was when the transistor was, was invented.

Uh, and then in the late 1950s, there was the invention of an advances in integrated circuits, uh, which is really the technology that allows you to put many transistors, uh, and other. Uh, types of associated electronic devices onto a single semiconductor chip and uh, sort of the continued advances in being able to do that over the next several decades are really what has enabled what we see in information technology, uh, today.

Hmm.

[00:08:59] Abbey Stanzione: Interesting how the invention of integrated circuits amplified the uses of semiconductors and electronics and what is really a short amount of time. To further explain, an integrated circuit is an assembly of electronic components in which hundreds to millions of transistors, resistors, and capacitors are interconnected and built upon a thin substrate of semiconductor materials, usually silicon, um, to form a small chip or

[00:09:24] Edward Yu: wafer.

Another thing that I will mention that happened in a similar, uh, time frame, uh, sort of invented in the late 1940s was the modern solar cell, right? Which is also, so solar cells, uh, which basically convert the energy in sunlight into uh, energy in the form of electricity are also based on semiconductors.

And in fact, the most common solar cells are made from silicon, which is the same material that is used to make just about all Uh, chips. Uh, not quite all, but the very large majority of chips for computing and communications. And so these, uh, the series of sort of very fundamental, very foundational, uh, inventions really set the stage for, uh, all of the advances that we have seen.

in semiconductor technology, uh, that have led us to, uh, you know, what we see now where, uh, semiconductors are ubiquitous in enabling, uh, the extremely powerful technologies that we have for computing, for smartphones, for communications. Uh, we’ve seen over the last 10 to 15 years, especially the rapid increase in the prominence of solar cells and solar energy in the renewable and sustainable energy landscape.

And that’s likely only to continue to increase things like solid state lighting. So LED light bulbs as opposed to incandescent or even compact fluorescent light bulbs, right? That’s something that, uh, the basic technology that enabled that, uh, the. The fundamental science breakthroughs came, you know, some of the most important of them came in the early 1990s, and then starting maybe around, uh, 2010 or so, we really started seeing, uh, LED light bulbs, uh, becoming much more prominent, and they have had a huge impact on, uh, you know, the way that we, uh, think about and design design.

and execute, uh, lighting and also a large impact on actually the amount of energy that’s used, uh, for, for lighting. And that has, uh, you know, really tremendous societal implications as well.

[00:11:44] Abbey Stanzione: Let’s talk more about the impact of LEDs. In 2022, the United States consumed 100. 41 quadrillion BTU, or burnished thermal units.

In fact, Texas is the largest energy consuming state in the nation, accounting for more than 12 percent of the nation’s total electricity in 2022. In a report by the U. S. and Energy Information Administration, 36 percent of the energy comes from natural gas. 31 percent comes from petroleum and only about 13 percent from renewable energy.

According to the department of energy lighting alone contributes to about 5 percent of greenhouse gas emissions worldwide. And if every household switch, just one regular light bulb with an energy saving model, like LEDs, we could reduce global warming pollution by more than 90 billion pounds over the lifetime of the bulb.

Which would be the same as taking 6. 3 million cars off the road. You touched on Dr. You, the research into materials and electronics can have a whole host of world changing applications, just from understanding how to engineer materials like semiconductors. I think one of the main areas of interest when it comes to semiconductors at the moment, or, um, within the news is.

The chips and science act that president Biden signed into law in 2022. This act made a 52 billion investment into the U S semiconductor and manufacturing research and the development and workforce. So I was wondering if you could talk a little bit about the chips act and maybe the impact that we’re seeing so far that has come out of manufacturing and the companies that are utilizing it.

[00:13:25] Edward Yu: Um, yeah, sure. So, uh, so, so I think the, uh, the CHIPS Act, or actually the, the CHIPS and Science Act, uh, you know, I, I think as, uh, a researcher and educator, uh, it was really fan and especially someone who’s involved in semiconductors, it was really fantastic, uh, to see this kind of legislation, uh, get passed.

Uh, where it really comes from is, I would say, the realization, uh, particularly for the CHIPS part of it, the realization That semiconductor chips really play a tremendously important role in many different parts of society today. I think that realization really hit home during the pandemic and the associated shortage of semiconductor chips, where all of a sudden it became very difficult for people to purchase.

cars, right? And, uh, so I think that it really helped, uh, people to realize that, uh, having a robust supply of semiconductor chips is important in many different parts of our lives. Some of the history, uh, and, and, uh, you know, when those chips are not available, then, uh, is very disruptive. Uh, some of the history of this is that, um, much of the fundamental technology for semiconductors and semiconductor chips was developed, uh, initially quite a few decades ago, largely in the United States.

Uh, not exclusively, but largely in the United States, but then in the late 1980s, and especially the 1990s, a lot of the semiconductor manufacturing infrastructure, uh, of which there had previously been, uh, a lot in the United States, a lot of that infrastructure and capability gradually moved to outside the U.

S., and particularly, uh, it moved to Asia, uh, such that You know, now the, uh, you know, the, the predominant, uh, I think, player in semiconductor manufacturing, uh, particularly at, uh, the most advanced technological levels is the Taiwan Semiconductor Manufacturing Company, TSMC. And so they are based in Taiwan, you know, and a lot of the semiconductor manufacturing capability overall is in Taiwan and other parts of India.

Asia. And, uh, you know, with the pandemic and the chip shortage, there was really a realization that, uh, you know, there would be a lot of benefits to having more of that infrastructure available in the United States. And, uh, so now through the Chips and Science Act, there will be, uh, substantial and very large new investments in semiconductor manufacturing technology in the U.

S. by, uh, both U. S. based and international. companies. And, uh, you know, as someone who’s involved in that field, that’s something that I think is important and very gratifying and reassuring, uh, to see. Uh, the other part of, uh, of that act, the science part of that act is, uh, really for, uh, renewed investment in fundamental science and in, uh, technologies that, uh, you know, are expected to have a large impact in, uh, You know, both the near and longer term future.

So things related to computing, communications, energy and and the like. And, uh, you know, that’s something that perhaps we don’t hear quite as much about it in the news, but I think has tremendously important and positive implications or could have tremendously important and positive implications for the development.

And sort of sustained advances in science and technology in the United States as well.

[00:17:33] Abbey Stanzione: Yeah, the impact of this one act has created in just last year is really exciting. I know companies have announced over one hundred and sixty six billion dollars in manufacturing and semiconductors and electronics.

At least 50 community colleges across the U. S. have announced new or have expanded programming to help American workers access jobs in the semiconductor industry. Here on campus, we’re already seeing the effect of the Chips in Science Act. UT Austin is leading the charge by sponsoring a new public private partnership between the state of Texas, preeminent semiconductor systems, and defense electronic companies, national labs, and academic institutions through the Texas Institute of Electronics, or TIE.

Ty is receiving $552 million from the Texas Chips Act to develop state-of-the-art fabrication facilities build a semiconductor ecosystem and advance the workforce development in this industry. We’re also seeing the impact through a $3.7 million partnership with Samsung Electronics that will not only help with the research development, but also help to recruit and support students to study semiconductor manufacturing within the ROE School of Engineering and other majors across UT Austin.

It’s really amazing the impact that we’re seeing so far with how many parts of our lives that it’s touching without even realizing. And so, as a researcher, you know, in the field of material science, how has your research been introduced into your lifestyle or your daily life?

[00:19:01] Edward Yu: Yeah, so that’s a great question, and, you know, my kids ask me about this sometimes, too.

Um, if you look at something like solar power, you know, back then, uh, you know, solar power was, you know, more than a curiosity, but certainly not anywhere near as prominent, uh, as it is today. Right now, you see many houses with solar panels on their roofs, uh, you can see that the implementation of solar power by utilities.

Combined with residences, uh, is really having a, uh, very substantial impact on how we think about, uh, electricity provision and how we implement, uh, electricity systems, uh, generally that’ll increase going forward, you know, in our house at that time, we had mostly incandescent and, uh, you know, maybe some compact, uh, compact fluorescent light bulbs.

Now, uh, they’re almost all And, you know, so that’s something that, you know, the kids can see, uh, some of it they’ve, you know, it’s just very, some things like smartphones, they’re very natural to, to the kids. They can, you know, they never knew a time really when there was not something like a smartphone, uh, available, you know, initially to their parents, uh, but maybe, you know, uh, now as they get older to them as well.

You know, so these are tangible things that, uh, they and we have seen, uh, in our everyday lives. I think there’s also an element of, uh, sort of a, what I’ll call a scientific way of thinking, right? Which, you know, given my occupation and, uh, and such is, is, is sort of a natural part of, uh, Uh, how I think about things generally, and, uh, you know, maybe by osmosis, uh, it gets transferred to, to the rest of the family, uh, as well.

And that is really, uh, sort of the. Desire to an interest in understanding why certain things occur, how they occur at a mechanistic level, and, you know, really constantly wanting to, uh, ask questions about why things work in a particular way, what would happen if such and such were, uh, were not true or, or were different.

All right? And, you know, I think that, scientific way of thinking and the scientific method of just trying things out, trying to do experiments to learn about the world and then to update one’s understanding of and picture of the world generally, you know, is something that, you know, I, I think we, uh, see and, and carry out.

Uh, in our family, uh, as well,

[00:21:44] Abbey Stanzione: I think it’s great that you were able to, and that you like to encourage your kids to think like scientists and engineers. I can think of a number of times when I was a kid and even, you know, as an adult where I asked my granddad a question and he would turn the question back around to me to kind of foster that, you know, scientific way of thinking.

As you said, do you have any specific memories like that with your family that you would be willing to share?

[00:22:08] Edward Yu: I’ll give you sort of one example of that from a number of years ago. This is with our daughter, who at the time was in late elementary school. She’s now a sophomore in high school. And, you know, since we’re here in Austin, and the sun, especially in the summer, is very strong, we would always you know, tell the kids, Oh, you have to put on sunscreen.

Okay, and that’ll protect you from the sun. So she was asking, Oh, well, you know, why do we need to protect ourselves from the sun? How does sunscreen work when I, you know, rub it onto my face or arms? After a while, it’s very difficult to see how does that protect us from, uh, from the sun. And so, uh, as you know, I started to discuss these things with her, we were able to get into Uh, things like different wavelengths of light, uh, you know, how sunlight contains many different wavelengths, and it’s the ultraviolet component, uh, of sunlight that causes damage to your skin, has, uh, you know, can have health implications and the like.

You know, when you rub sunscreen on yourself, you don’t necessarily… see it after a while, but it’s still there. And what it’s doing is it’s blocking the ultraviolet light, which is present, but you can’t see it with your eyes. Uh, and, and so that got her very interested in, uh, you know, different wavelengths of light that are in sunlight and so forth.

And so, uh, so what we did was, uh, it turns out that there’s a very interesting kind of home science science. Yeah. Uh, project that one can do. If you, uh, if you go to a website called publiclab. org, uh, it was more active at that time. I think it’s less active now, but you can still find it. Uh, they have instructions for building a spectrometer, which is a device that splits light into its constituent wavelengths.

It spreads it out, uh, spatially, uh, and you can build this from a cardboard cutout. But they provide a template for you on the website. And if you take apart a, uh, DVD, right, then the very finely spaced lines that you have on the DVD, uh, cause what’s called diffraction of light, which is basically splitting light into its, uh, you know, the, the angle at which it comes out, uh, depends on the wavelength.

And so what you can do is you can build this thing, you put it up against the camera of a smartphone, and… Uh, you take a picture of it, and it shows you how the light that came in is distributed, uh, in wavelengths. So, uh, so we built this thing together, and, uh, she was really able to learn a lot about, uh, different wavelengths of light, uh, you know, light that you can see, light that you can’t see, uh, you know, aspects of, of color, uh, and, and so forth.

And, uh, you know, so there are actually a lot of these, you know, very accessible kinds of things that one can do. at home, uh, really quite inexpensively in many cases that, you know, can be, uh, tremendously instructive about different parts of our world, including, uh, things like materials, light, and, and, and so forth.

[00:25:24] Abbey Stanzione: What a fun project that you were able to do at home with your daughter. I could see how that would add to the excitement and hopefully gave her, and possibly other kids, the confidence to become future scientists and engineers. Speaking of future engineers, what do you think might be coming up in the future in the area of semiconductors, or specifically within the IRG 2 research group or within your research lab?

[00:25:47] Edward Yu: You know, what we see going forward in, uh, say semiconductors, uh, generally in some of the research that is going on in, uh, our center and the like, uh, if we talk about, uh, you know, semiconductors first, then, you know, the technology for semiconductor electronics and computing and the like is, is already extremely sophisticated and advanced, right?

It’s, it’s, It’s, if you think about what is actually done in semiconductor manufacturing and fabrication of computer chips, uh, you know, it’s, it’s really astounding, right? To think that, uh, you know, we can make structures that are say, tens of atoms wide, right? On a semiconductor chip, chip, and we can make of order a hundred billion of them and get something working.

Uh, out of it, right? It’s it’s incredible that that, uh, can be done. Um, but, uh, you know, even though, uh, it’s already extremely sophisticated, there are a tremendous number of new things that are, uh, that are coming up. Um, you know, so on the materials, uh, side of things, right? Right now, uh, silicon is the predominant material, in, uh, computing, uh, and, and semiconductor chips.

And it will probably remain that way for, uh, the foreseeable future, but there is, uh, more and more interest and, uh, you know, greater and greater implications from being able to bring in other types of semiconductor materials as well, either as standalones or, uh, integrated with, uh, silicon based. Uh, semiconductor chips.

So for example, for, uh, electronic chips that can operate at a high temperature and or high power levels, right? So high temperature can be important if, uh, you have chips that are, say, near the engine of a car. Right. And, uh, high power handling capability, uh, is important for applications where you’re building devices that will play a part in the, uh, electricity infrastructure of, of the U.

S., which, uh, you know, is, uh, something that is huge in scale. And, uh, Right. Right. certain parts of it can very much use, uh, modernization. So, uh, actually for those kinds of applications, you need semiconductors that have somewhat different properties from silicon. You know, outside of, uh, sort of electronics, there is tremendous interest in, uh, and a lot of activity in, Uh, new materials for, uh, solar energy, for example.

So, uh, some of you in the audience may have heard of what are called perovskite, uh, materials, which are of great interest for, uh, solar cell applications because they can be quite inexpensive. Uh, they, uh, have increased very rapidly in their performance, uh, their efficiency in, in solar cells, and, um, you know, could have, uh, You know, they, they have a lot of promise for improving the performance of and reducing the cost of certain types of, of solar cells.

So that’s something that, uh, can have a very substantial impact given now the prominence of, uh, solar energy in our power infrastructure generally. And then, uh, there’s the tremendous, uh, activity and interest in, Uh, quantum phenomena, quantum computing, uh, quantum communications and the like. And, uh, semiconductor materials are likely to play a very central role in, uh, developments in that field, uh, as well.

And some of the things that we are researching in the center, again, in the atomically thin materials area, uh, could be very significant in quantum. Uh, computing communications applications, uh, as well. So… Uh, so those are a few areas where, uh, you know, I think there are, uh, some very exciting developments that are coming to the fore and that will be very important, uh, going forward.

And uh, just a little bit about how some of the work that’s being done in the center connects to, to those

[00:30:13] Abbey Stanzione: areas. So in your opinion, do you think that with the increased demand in the, in the market that the companies and industries will start popping up? And if so, why do you think that? And also, why do you think the improvements in this area are important?

[00:30:30] Edward Yu: Yeah, I think that’s a great question. And so if we talk about semiconductor technologies generally, uh, I think there are a couple different aspects to it. One is, uh, are we going to be seeing more companies involved in and capable of producing semiconductors, say, mostly silicon based semiconductors at the most advanced technological level for computing rights.

And so that really means, uh, Making the smallest feature sizes on a chip, scaling those two large areas, packing as many transistors as possible into a given area of a computer chip. And there, um, you know, right now there’s there’s one clear leader in that area, TSMC. And there are, you know, maybe a couple other companies that are close to that level as well.

Um, now going forward, I think that Things like the CHIPS Act and generally increased investment in the U. S. and worldwide in, uh, advancing semiconductor technology, um, will probably increase the number of players, uh, that have that kind of capability really at the most advanced level, uh, or at least maybe help some of the companies that are a little bit behind, get up more efficiently to the state of the art.

I don’t think the number of companies that are, that have that kind of capability will be extremely large just because of the cost of building a really state of the art semiconductor manufacturing facility, you know, at that level. It’s, it’s of the order of 10 to tens of billions of dollars, uh, you know, for a facility at that level.

And so, you know, just the scale of that expense is going to limit, uh, the number of companies that can realistically Uh, operate, uh, in, in that regime. Now, having said that, I think there is, uh, tremendous potential and, and already a lot of activity, uh, in, uh, what I’ll call more specialized semiconductor manufacturing.

So that might be, um, making chips that don’t have quite the smallest features. Right. But where you can integrate different types of structures, have different kinds of fabrication processes involved and so forth that are very important for a variety of applications, say in communications and sensing and the like.

So, um, so there, I think there is room for and there will be an increasing number of players and manufacturers. In, uh, areas that involve, uh, other semiconductor materials,

[00:33:31] Abbey Stanzione: it sounds like there’s a lot of potential for growth in the area of semiconductor manufacturing to expand. And you know, that’s one of the many reasons we as a center try to foster at the elementary and middle school level specifically.

That’s STEM education and why we have outreach at local Austin schools, because we’re going to need this future generation of scientists and engineers, you know, along with the current generation of undergraduate and graduate students, they’ll need to enter the workforce with an interest and a passion for making these developments for society.

And I hope that this episode will help with that. I would like to say thank you to Dr. Yu for sitting down with me today to talk about the history and the importance of semiconductors and where you see the future of research going.

[00:34:17] Edward Yu: Thank you very much, Abby.

[00:34:18] Abbey Stanzione: That’s all for today’s episode of the Materials Universe podcast.

I do have a correction to make from the trailer episode released on October 13th. A piece of human hair is about 50 microns thick. For reference, atomically thin materials are usually on a length scale smaller than 5 nanometers. So that’s about 10, 000 times thinner than your hair. If you’d like to learn more about anything we’ve talked about today, please check out our show notes for helpful links.

Thank you for listening to my interesting conversation with Dr. Edward Yu. We hope that you’ve enjoyed learning something new. Please leave us a review and share this podcast with your friends or family. You can follow us on social media at texascdcm on Instagram and X. Thank you to the National Science Foundation and the University of Texas at Austin and an additional thank you to the Lattice Audio Studio crew for their help with the production of this podcast.