by summerstudent Nora Jung
Sitting in my organic chemistry class two semesters ago, I heard the whispers of a word repeated often amongst my classmates. I was only in my second year of my undergrad and the pressure of finding a research position was a constant reminder in the back of my head. In January of 2022, I applied for the summer research position at HZB and it felt like a step in the right direction, but I was still unsure about what lay ahead. What does it mean to do research? Am I qualified enough? Will I know the right answers?
When I received the invitation to be part of the program, I initially was thrilled but intimidated at the same time. I read the project proposal from my supervisor and found myself stumbling over every other word. What are perovskites? What are defect states? How do I interpret Surface Photovoltage Spectroscopy?
First Steps into a Foreign Language
On the first day of work at HZB the other summer students and I faced our nerves as a group, navigating a new environment and institute, and getting to know one another. It was on this first day during a welcome conference where I learned my first new language: how to communicate with other scientists and establish a common ground in different levels of understanding.
New Materials for Solar Cells
Later that day I sat with my supervisor to discuss the project I would be working on, which would involve detecting defects in chalcohalide-based thin-films, a current interest in the field of photovoltaics as an alternative to more toxic, lead-based thin-films. Chalcohalides consist of elements from groups 16 (chalcogens) and 17 (halides) of the periodic table. To detect these defects, Surface Photovoltage (SPV) measurements are used. SPV works by exciting charge carriers (negatively charged electrons and positively charged holes) using different wavelengths of light and separating them in space. This separation of charges gives us a voltage and therefore a signal which can detected with the SPV instrument and analyzed using a computer program. The analysis of SPV spectroscopy can reveal defects in the material, or other properties of the semiconductor, useful for determining its efficiency if applied in a solar cell.
(Now, most of the terms in this last paragraph were foreign to me up until about a month ago, so “please excuse my physics”, as I am still learning.)
Molding Concepts of Chemistry and Physics
In talking with my supervisor on the first day, I realized there was another language I needed to adjust to: the language of physics and photovoltaics, which I didn’t normally converse in. As an example, when my supervisor explained the band gap in semiconductors to me on the first day, I was initially confused by the concept of a valence band and a conduction band (the band gap is an important region we analyze with SPV where those defects can appear). But when I related the band gap to the energy gap between the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) from chemistry, I was better able to grasp the concept. Small differences like this made the biggest difference, until I realized that the best way for me to learn this new language was to mold my knowledge of chemistry and approach new concepts from this perspective instead of trying to completely change the way I think.
My knowledge of the language is slowly expanding, and I find myself talking in a tongue that used to be foreign to me. I am finding a newborn comfort conversing in the scientific jargon that once intimidated me. To me, research is adapting, collaborating, and asking questions. But most importantly, it is a journey of discovery not just in the world of science but in the world of language.
On the Author:
Nora Jung is in the 3rd year of her undergraduate degree as a chemistry major at the University of California, Los Angeles (UCLA). The summer student program is her first research fellowship. She is interested in environmental chemistry and using sustainability as a guiding force in her everyday life.