Q: Thank you for accepting this interview. Could you begin by detailing how you came to be involved in your research group?

A: Thank you so much for instigating this interview. It is a real pleasure to speak about my work and bring IBS to a wide audience. I began my professional career in late 2013 when I started my own lab. I became interested in BP due to Professor Yeonjin Yi (coauthor of recent paper). He gave me some samples to look at and told me I might find them interesting to gather the properties of 2-D materials. I thought, initially, it looked so curious, like clay. I wanted to touch it and remold it into different shapes to control its electronic properties. I had previously studied graphene and attempted to open the band gap but that turned out to be quite difficult so I decided to try another route and start with a 2-D semiconductor and tune the band gap to implement the similar properties as graphene.

Q: And from this you began to test black phosphorus (BP), what role did you play in the lab while testing and were there any difficulties you had to overcome in reaching your results?

A: Well yes, quite a few difficulties actually. But with regards the lab and my role, I was a typical professor and supervised five students. One of whom was my first student so I gave him the most important idea that I had on BP. As a principle investigator I tried to offer the students more freedom to experiment as that’s more in line with my own academic background. We went to the States and worked night and day in the lab in Berkeley’s synchrotron radiation facility. We spent five days in the lab attempting to gain a clear vision of the band gap. It was exhausting and extremely tiring. Of the five days, I think we slept for just maybe two days. Our focus and determination were incredibly strong – the Asian way I suppose. Our will power wouldn’t yield until we had a clear vision of the band gap. We persisted and finally got the results we wanted. We endured so much hardship but in the end it was worth it. I was physically drained (laughs) but at least we had this success to show for our exhaustion and determination!

Q: Indeed. It sounds like it was quite physically draining. Can we talk a little about when, or how, you first began to show promise of being gifted in science? Was it nurtured in school or develop much later?

A: Oh, that began a long time ago when I was in middle school. I was interested in chemistry and atoms - the minimum unit that makes up the entire universe. By adding up the number of nucleus in the atom we can change the properties of that element. To understand the physical properties of the element it is more important to study physics and that’s how I came to be interested in physics rather than chemistry. It was very exciting and interesting to me.
Funnily enough as an undergrad student I was not such a good student. I studied very hard in high school, as all Koreans do, but in university I maybe enjoyed myself a little too much. I was more interested in expanding my social network and parties (laughs). In my graduate school I met my supervisor and became more focused on surface physics. It was new to me and quite interesting. I remember visiting Pohang’s synchrotron radiation facility and observing tests, how new data was achieved and finding something new from existing data fascinated me.

Q: Your educational background is varied. You began in Yonsei University then moved to Berkeley and Berlin. Could you take us through that journey?

A: It was my military service which, in a way, dictated my educational journey. I spent my first year in Yonsei University then half a year in POSTECH and my remaining time was spent in Berkeley in California. I applied to three universities who were active in area surface science; two were in America (Chicago and Berkeley) and one in Europe (Switzerland). Berkeley was the only one which responded so I had no choice and left for California to the Lawrence Berkeley National Laboratory. Germany came much later, near the end of my third year in America before I completed my PhD.

Q: Did you have any major difficulties adjusting to life in America?

A: Oh, well, firstly the weather is quite different. Berkeley is wonderful in the summertime and winter. It’s not like Korea where the humidity can be suffocating. The research culture is also drastically different. In Korea supervisors have a very strong opinion and shape the research and where it’s going. In America you are given a lot more freedom to create and use your creativity. My supervisor allowed me greater autonomy and I really enjoyed that freedom. I could decide everything. It was so helpful, especially when I returned home and began to shape my own lab.

Q: And from here Germany creeps into your story?

A: Hmm, yes. Near the end of my final year in Berkeley, I went to Berlin to the Fritz-Haber Institute in Berlin to experience how to make high-quality graphene. I really enjoyed my time in Berlin, the coffee was great! Living in Europe is a lot different from living in the US. I didn’t find many Koreans there so I was a total foreigner but I found it interesting. I had more free time to visit museums and historical sites and it was a terrific experience to have from such a short period of time. I remember fondly my time spent in both Berkeley and Berlin.

Q: You gained your PhD in February of 2010 when you were just 29. How did that feel to gain such a milestone at a young age?

A: I worked hard for four and a half years. Typically in Korea people spend more than six years studying before they get their PhD. During my time studying I was so focused on my research. Starting from 2005 I felt a strong interest in the research itself and read all the papers available to me. Thinking on it now, I can only remember time spent on the research. So much focus. I don’t feel especially gifted; what people can do in six years I feel can be done in four and half with enough focus and dedication.

Q: How do you feel about being established within IBS? Having achieved so much at such a young age, do you feel an extra burden to perform and reach, perhaps, unattainable goals in the future?

A: One of the founding philosophies of IBS is autonomy and the freedom this offers for creative research. This is a great step for us, as scientists, to advance the field of basic science. I feel some pressure from POSTECH and from IBS and do feel a certain burden to perform. I think it is very important to make a positive step that is meaningful to scientific community. To achieve this, in the short term, I wish to make a strong research group that can steadily publish papers in high-impact scientific journals. Regarding IBS, it is also important to produce really meaningful research to justify heavy investments from the Korean people. I feel a lot of responsibility but I am optimistic for the future.

The news story on Professor Keun Su Kim’s research on BP can be accessed here on our IBS News Center

Interviewed by Neil Mannix