Hee Joo Choi ’21


Chemical and Biological Engineering

Project Title

Ensuring the Sustainability of Perovskites, a Potentially Transformative Solar Material

Presentation Link

View Hee Joo 's Presentation

Perovskite solar cells have recently gained popularity as a possible alternative to siliconbased solar cells due to easier and lower-cost manufacturing. They have yet to be commercialized, however, because perovskites are unstable and degrade quickly when exposed to elements such as humidity and oxygen. My internship explored the effect of humidity and air on the degradation patterns of tin-based and PEDOT-based (an organic mixture) electron transport layers in photovoltaic perovskite films. I monitored the environment in which films were degraded by manipulating the relative humidity, then taking X-ray diffraction (XRD) scans of the films throughout the stages of degradation. As a result of my internship, I learned to operate the XRD machine, interpret its data, and code in R software to create plots and overlay data. I also learned how to create perovskite films and their characteristics. My research will aid in understanding more about perovskite degradation and its byproducts. This internship helped me realize that I’d like my future career to be related to the environment. I’m also considering postgraduate education after my time at Princeton.

Internship Year


Project Category

Alternative Energy


 Myneni Group, Department of Geosciences, Princeton University- Princeton, New Jersey


 Satish Myneni, Professor of Geosciences; Clay Hamill, Ph.D. candidate, Chemical and Biological Engineering; Sara Thomas, Postdoctoral Research Associate, Geosciences