Distinguished Professor, Australian Laureate Fellow and
Head of the Semiconductor Optoelectronics and Nanotechnology Group
Australia National University
- B.Sc., Physics, Nagarjuna University, Guntur, India
- M.Sc. (Tech), Electronics, Andhra University, Waltair, India
- M.Phil., Physics/Materials Science, University of Delhi, India
- Ph.D., Physics/Materials Science, University of Delhi, India
Jagadish is currently an Australian Laureate Fellow, Distinguished Professor and Head of Semiconductor Optoelectronics and Nanotechnology Group in the Department of Electronic Materials Engineering, Research School of Physical Sciences and Engineering, the Australian National University. His research interests include compound semiconductor optoelectronics and nanotechnology.
Advice to Students:
Depending on what you're passionate about, go and get a basic degree in that area first. It could be chemistry, or physics, or materials science, or electronic engineering, or chemical engineering, or mechanical engineering, or biology, or medicine, or whatever you like, or feel passionate about -- then go and specialize at a masters or PhD level.
Q: When did you first find that your career path focused on nanotechnology?
Jagadish: Mainly we have been working on a range of microtechnologies, and so we have been working on quantum wells, and quantum wires, and quantum dots. It's very interesting that when we started doing this work, people used to say "you don't do much of nano." But the quantum technologies which I'm talking about are nanotechnologies. I think around mid-90s, we started realizing that unless otherwise you start using the word "nano," then people may ignore what you're doing and think it isn't nanotechnology. I used to call my group Semiconductor Optoelectronics, then I started calling it a Semiconductor Optoelectronics and Nanotechnology group -- just to make people aware of it. We need to be careful and not ignore certain components of the technology, because they're not referring to it as "nano" so it doesn’t fall off the cart.
Q: What current nanotechnology applications are you working on?
Jagadish: Mainly we have been working on quantum dot solar cells and nanowire solar cells. Energy is beginning to be such an important issue globally and none of us have got a single solution, so it's important that we as a global community all work together to try to address some of these challenges. There are lots of technological challenges we'll need to get over in terms of enhancing efficiencies of the renewable energy sources, whether it is solar energy, or wind energy, or wave energy, or whatever the technology is. We have mainly been working in the past on quantum dot lasers, quantum dot infrared photodetectors, but it was logical for us to really extend our experience in technology in the area of quantum dots to push into the technology of solar cells. We really try to understand how we can improve the performance of an existing solar cell by incorporating quantum dots.
It turns out that though technically you're predicting that this will improve the performance of the solar cells -- in terms of its actual performance, it slightly improves in one aspect, like increasing the current of it, but the voltage drops -- so in the process the overall efficiency is going down rather than going up! That’s where we are really trying to understand what the mechanisms are that are controlling these processes, and unless you understand the fundamental physics of these devices, it’s going to be very difficult for us to improve their performance. That's what we're focusing on at the moment.
And, we have been working on nanowires now for 6 or 7 years or so. Our original aim was to really work on quantum nanowire lasers, and nanowire single photon sources, and nanowire photodetectors, and then most recently we realized that nanowire solar cells have also got great potential -- so then we started working in that area. So, basically, we are looking at both nanowires and quantum dots for a range of applications in the optoelectronics and photonics fields, including photovoltaics and solar cells.It turns out that though technically you're predicting that this will improve the performance of the solar cells -- in terms of its actual performance, it slightly improves in one aspect, like increasing the current of it, but the voltage drops -- so in the process the overall efficiency is going down rather than going up! That’s where we are really trying to understand what the mechanisms are that are controlling these processes, and unless you understand the fundamental physics of these devices, it’s going to be very difficult for us to improve their performance. That's what we're focusing on at the moment.
Q: What's the most rewarding thing about working with nanotechnology?
Jagadish: The most exciting thing is to see that in the past, we have been theoretically predicting lots of exotic phenomenon and exciting science or physics taking place at these levels. But through nanotechnology, we suddenly have an opportunity to be able to verify those physical concepts. Then being able to verify whether they are working or not and then whether those principles theoretically were what was predicted experimentally can be validated. It is also very, very exciting and interesting for me to be working with my students and post-docs -- this is really the most exciting and stimulating part of it. I feel that our job at the university is to train the next generation of scientists and engineers – and also to explore new ideas.
Q: Is there an example you can provide that shows how something you’ve worked on has positively impacted the world?
Jagadish: Some of the things which we have been developing, such as the infrared detector technologies, have been used for a broad range of applications -- for medical imaging -- to manufacturing applications -- and defense applications and so that's the sort of thing that gives you satisfaction. You may have done the work long ago, but now suddenly they're finding applications.
Another area which we have been working on are high power lasers, semiconductor lasers. They are tiny lasers, but now they're used in the CD and DVD players, and in the optical communication systems. It is really nice to see that things which you once predicted would be useful, are now in widespread use. I can't imagine the modern life without lasers. People may not realize it, but all of us are using lasers all the time -- in printers, and CD and DVD players, and of course when you pick up your phone. So it's nice to see some of those technologies that you have been working on for the past 20 years or so now moving into real-world applications. Of course it's a range of technologies that need to come into place, and also a range of people have got to get into these technologies. We all work together by contributing in a small way whatever we could into those technologies.
Q: What do you think is the single greatest impact nanotechnology has had on the world thus far?
Jagadish: If you are asking where nanotechnologies have already been used, people are using it in sunscreens for example, and also in paint. You've got nanoparticles included in paint so that they absorb UV light. When you look at the degradation of the performance of wood, it's mainly due to the UV exposure. Nano has also been used in self-cleaning windows, and heat-resistant coatings. People are using some nanoparticles as catalyst particles, which are used for enhancing the catalyst process in cars, too. So nanotechnology has already helping in terms of reducing the energy usage, and in terms of reducing greenhouse gas emissions. From that point of view there are already lots of applications.
It also depends on how you define nanotechnology -- if you talk to different people they all have a different definition of nanotechnology. Not that they're wrong, that's because they're coming from different perspectives and have a different view for looking at these sorts of things. Physicists, and chemists, and engineers, and biologists, and materials scientists all working on the same fields, are all looking at it from their own perspectives or points of view. When you define that nanotechnology as anything from 1 to 100 nanometers, in principle you can say that currently all the computer chips are using nanotechnology.
Q: Please give an example of what you envision nanotechnology applications leading to in the future.
Jagadish: In the future, I am hopeful that the energy industry will have a large impact from nanotechnology -- whether it is improved fuel cells, or improved catalysis, or improved battery storage technologies, or improved conversion of light energy into electrical energy -- that's an area where you will have a significant impact. In fact, energy is an area that we need to really focus on because energy is a global issue -- and if you solve the energy problem you solve lots of other problems as well.
Another area which is important is clean drinking water. Membrane technologies exist, where we can use these membranes as an energy efficient way to do the desalination of water. There are also some porous membranes where we can control the porosity, so only the water molecules can pass through, not bacteria or viruses.
And another key area for nanotechnology is healthcare and environmental issues. We can explore how to use nanotechnology to get rid of toxic waste, or for converting toxic waste into stable forms. Already people have been using nanomembranes and nanosponges to be able to absorb oil spills -- these applications are going to be more and more important.
In terms of long-term health issues, nanotechnology has played a very important role, and that's one area in which you can already see there's an impact. Using quantum dots for imaging applications is better for resolution than when people were using dye -- this is important when you're dealing with complex things. So in terms of diagnostics, nanotechnology is going to play a very important role. And already drug delivery in general and targeted drug delivery in particular has had an impact. For example, nowadays if you look at the cancer patient, they get bombarded with huge amounts of radiation or chemicals. If instead we can send the targeted drug delivery directly only to the cancer cells, we don't affect the other cells. You will not only be able to reduce the drugs but also reduce the costs, and also side effects will be reduced or eliminated -- so that's an issue which will improve the quality of life quite significantly. Of course it will take a long time because of safety and regulations. But Health area is going to have a really big impact, we need to have more groups working on these important areas.And another key area for nanotechnology is healthcare and environmental issues. We can explore how to use nanotechnology to get rid of toxic waste, or for converting toxic waste into stable forms. Already people have been using nanomembranes and nanosponges to be able to absorb oil spills -- these applications are going to be more and more important. Another area which is important is clean drinking water. Membrane technologies exist, where we can use these membranes as an energy efficient way to do the desalination of water. There are also some porous membranes where we can control the porosity, so only the water molecules can pass through, not bacteria or viruses.
Q: Do you find yourself working more in a team situation, or more alone?
Jagadish: It's a team effort. In fact, science is becoming so interdisciplinary these days, you just can't do much on your own, and you can't be an expert in everything. If you want to achieve the goals of the product or process, you really need to have in your own team those people that are complementing you. In fact, my philosophy has always been: do your job the best possible way you can, and develop your core competency, and then in other areas where you need help, go for the best people in the world, irrespective of where they're located.
Q: If you work more as a team, what are some of the other areas of expertise of your team members?
Jagadish: Really, you can't be an expert in everything. So, what we try to do is try to bring a team together, and then work together as a team. That collaboration is an important thing, and really that's the strength of my research is really my collaborators and my own team. Even in the early 90s, I was collaborating with people in China, in Lithuania, in Poland, in Sweden, and it doesn’t matter where they are. You just have to go and do that, and of course now, the modern communications help quite a lot in terms of enhancing the get things done sort of thing. Even then, when we didn’t have these fast communication systems, we used to send faxes and sort of things, and really reach out. If you feel passionate about science, and you feel passionate about solving a problem in the most effective way, then you just go and find people equally passionate about solving that problem.
Q: Did your university training help you in your nanotechnology work?
Jagadish: Yes, I'm sort of in a unique situation in the sense that I've had a background in physics, electronics, and materials science. And by working in nanotechnology, that background has really helped significantly in what I've been able to achieve.
Q: Do you have a mentor? Did you in your college years?
Jagadish: Mostly, in my life, the two people who I give a lot of credit are two high school teachers of mine. In fact, when my parents migrated to a remote village, where there were no high schools, I stayed with one of my mathematics teachers and also learned from English/ social science teacher. Those teachers have really molded my life. One teacher was really strict. Essentially he believed that hard work and discipline were very important things. So in those days, you know you're allowed to beat kids. So if you're not behaving yourself, you get a slap in the back. I lived with him for three years, so I've learned how to be disciplined, and how to do hard work. The other teacher taught me the need for being humble, and being simple, and being a good human being, despite all adversities you have. He taught me to then maintain my humility and dignity. So really, they both have played two different roles -- so I try to really combine those two skills -- I work crazy hours, and 60-hour weeks are pretty common for me for the last 20 years or so. But of course, if you're enjoying what you do, you're having fun. And, if you get paid for it too, it's not a bad job to have!
The philosophy that I live by is to give something to the community and the people around you. That's important I think.
Q: If you had to do it all over again, would you still focus on nanotechnology applications?
Jagadish: Well I'm having fun, and I don’t have any regrets. The only regret, if I have one, is that probably I should have spent a little more time with my daughter when she was young than I did. I'm so passionate about what I do, and I'm so committed to the science and engineering that I'm doing. So I have made some personal sacrifices, and probably my family hasn’t seen me as much as they should have -- particularly my daughter. And now of course, she's 21, and she doesn’t need me. So that's the only thing which I would change in my life. Other than that, I really don’t have any regrets, and I enjoy what I do, and we're having great fun. And I've been lucky that I've had so many wonderful opportunities and wonderful people to work with.
Q: What advice do you have for pre-university students?
Jagadish: Generally, whenever you're trying to do nanotechnology, particularly if you're doing engineering aspects of it, we first study about mathematics, physics, and chemistry as the three basic sciences, and then go on and study engineering, whatever the discipline. I would also really encourage students to add biology to their repertoire. Because, nowadays, in these multidisciplinary fields, knowledge of biology also plays a very important role, and that will really help them to be able to address the complex problems which we will try to solve. And the other thing I would say is that hard work is important in life, and however bright you may be, without hard work you cannot reach your goals. Also, try to develop discipline, choose a topic or field which you enjoy, and have fun. I think students have to really develop that need for hard work, because there are so many distractions particularly for kids these days. You can spend many hours sitting in front of a computer, and being on Facebook, and responding to messages from somebody or another, but then you haven’t really focused on the core business that you're looking at. So despite all the distractions, students need to be able to focus. Also, learn as much as you can, and you never know when what you're learning today will be helpful to you.
I was doing physics, then went into electronics and materials science, I was not too sure what it would lead to, but now I am better for it. So that's why knowledge is never a waste of time, and the more you learn the better. Someday it will be useful for you. Try to be open-minded and learn as much as you can.
You also don't know what technology of the future will be, so don't become too specialized too early in your life. Depending on what you're passionate about, go and get a basic degree in that area first. It could be chemistry, or physics, or materials science, or electronic engineering, or chemical engineering, or mechanical engineering, or biology, or medicine, or whatever you like, or feel passionate about -- then go and specialize at a masters or PhD level.
Also, try to take risks. There's nothing wrong with taking risks. You may start out with one course or subject, and explore and see how much you're enjoying it. If you don't like it, don't worry too much about it, move onto the next one, and find out which one inspires you. The important thing is to choose something that you really feel passionate about -- if you're enjoying what you're doing, you can be successful anywhere. That's my philosophy of life.