Professor Ryu Seung-yoon teaches physics in the Department of Physical Semiconductor Science at Dongguk university. In January this year, Professor Ryu’s research team published the results of their research using medical equipment to present indicators for radiation exposure based on solar cells. The Dongguk Post intends to provide an opportunity to find out about the solar cell-based radiation research process and how to solve the difficulties he faced during experiment through interviews.
Q1. Please introduce yourself.
Hello, I am Professor Ryu Seungyoon from the Division of Physics and Semiconductor at Dongguk University. To briefly introduce my background, I have been working in an Industry-UniversityInstitute Collaboration. I conducted research on OLEDs in Samsung SDI/ Samsung Display, and I worked as a senior researcher at the Institute of Materials Research in Changwon. Subsequently, I came to the university, aiming to share my experiences gained in these three different settings with students and to contribute to the development of national competitiveness by dedicating efforts to education for nurturing talent.
Q2. Can you briefly introduce the division you take part in, and your research field?
In the Division of Physics and Semiconductor, students study both physics and semiconductor science. Physics, with its etymology rooted in Physika (natural science), is the study that aims to understand the essence of everything. In the realm of physics, learning challenging concepts is essential to grasp the essence, but understanding the approach taken in physics education is truly meaningful. The process of generalizing principles in the vast world of data and validating them through experiments is akin to understanding the world. Additionally, our division, specifically in the semiconductor science major, aims to cultivate individuals who contribute to the technological advancement for creating high-added value in semiconductors—one of the nation’s key projects. I believe that the fundamentals of physics can be applied to semiconductors with great utility. Following the introduction of the division, we are not only dedicated to education but also actively engaged in research. Our lab is called the Energy Photoelectric Conversion Laboratory. Light from the sun and the light emitted by fluorescent lamps, both considered as energy, are referred to as photons. In our lab, we primarily focus on the research of the mutual conversion of photons and electrons, notably in the realms of OLEDs and solar cells. These days, in line with the changing research trend, we are studying nextgeneration electronic devices utilizing organic semiconductors. In addition to next-generation electronic devices, we are also interested in healthcare, conducting research on photodetectors for skin treatment. Our recent study on radiation exposure indicators, presented in collaboration with Professor Cho Shin-haeng from Chonnam National University Medical School, delves into technologies applicable in extreme environments, such as medical radiation dosimeters and outer space.
Q3. Please explain in which field the research on presenting radiation exposure indicators operates, how, and why it is important.
The presentation of radiation exposure indicators is not the first to be presented in this study. Commercially available devices known as dosimeters are already in use. To simplify the concept of the radiation exposure indicators proposed in this study, healthcare professionals working in radiology departments assess the amount of radiation exposure every quarter and undergo annual health check-ups to examine their radiation exposure doses. However, our research began with the question of whether there could be a way to assess their radiation exposure levels in their everyday lives. The level of experiments might be far from commercialization yet, but what we have suggested was that the indicators could be presented through solar cells, which are representative of energy photoelectric conversion. Whereas conventional radiation dosimeters cannot be carried by individuals and be measured regularly, we are working on further research to develop a simple form that can be attached to the skin to measure radiation exposure levels more conveniently. As for the question of why this research is important, I would like to offer a slightly different perspective. Recently, there has been a growing recognition of the need for convergence in various fields. I believe that bringing together experts from different fields can sharpen technology even further. I would like to emphasize the significance of our research by suggesting that collaboration with healthcare professionals can interpret and approach these aspects in the form of convergence.
Q4. Among various methods to express radiation exposure indicators using solar cells, is there a reason for utilizing “medical equipment”?
The term “radiation exposure” alone carries significant risks. Exposure, when accumulated, can pose threats to life. Those working in hospitals, in my opinion, are the most capable and adept at handling such radiation in the safest manner. Thus, collaboration with hospitals was essential for research on radiation exposure. The decision to utilize medical equipment was influenced by the high level of trust associated with medical devices, as they are used on patients, and by the consultation with Professor Cho Shin-haeng.
Q5. What impact do you expect this research to have on academia?
At the current research stage, I find it challenging to anticipate a direct impact on academia. However, as I mentioned earlier, I think it would be great if the convergence of medical and semiconductors could be presented in a way that leads to a change in perception, and contributes to the advancement of technology in various forms of convergence.
Q6. Were there any challenges or difficulties encountered during the course of your research?
Experimentally, the stability of the perovskite solar cell we used was still not in good condition. This posed difficulties in the fabrication and analysis of the components. However, despite the instability, the perovskite solar cells demonstrated a strong radiation tolerance compared to conventional solar cells. This characteristic made the research more manageable than studies utilizing organic materials. Theoretically, since our research involved the convergence of different fields, there were challenges in understanding each other and studying to verify whether the hypotheses presented were accurate. Despite the difficulties in this process, it is gratifying to see that the effort resulted in positive research outcomes.
Q7. As a researcher, what do you think should be the future research direction for the field of physical chemistry in South Korea?
In my opinion, the fundamental aspect of research direction lies in understanding the roots. To use an analogy, it's like tracing the roots of a very large tree, aiming towards the deepest part. Even if the destination may not be the deepest point yet, it is crucial to share the experiences and approaches with other researchers, minimizing trial and error, and collaborating to eventually reach the deepest point. In terms of research, this translates to collaborative research, applying methods used in different fields to discover the deepest roots of physical chemistry. By incorporating approaches from various disciplines, we may uncover the deepest roots of the “physical chemistry tree.”
Q8. Please introduce your future research plans.
Future research plans are to create wearable devices, one form of nextgeneration optoelectronics, through the combination of healthcare and energy photoelectric conversion elements devices. The goal is to produce devices that can easily monitor health in daily life. Moreover, I plan to develop transparent and flexible optoelectronic devices. Through this, I intend to explore a world where expansive displays can be unfolded and folded, even in confined spaces such as vehicles.