Doctoral Students
Hyeongjun (Jun) Koh
E-mail: hjkoh@seas.upenn.edu
Biography:
Jun received a Bachelor’s degree in 2016 and a Master’s degree in 2018 in Chemical and Biomolecular Engineering from Korea Advanced Institute of Science and Technology (KAIST). He is a Ph.D. candidate at University of Pennsylvania and joined Stach’s group in 2019.
Research Interest:
Before moving to Stach’s group, his research was focused on understanding the electrical behaviors of Ti3C2Tx MXene films upon gas exposure through in-situ XRD during his Master. In Stach’s group, he is currently interested in in-situ and ex-situ exploration of Li-metal batteries using Cryo-TEM.

Jeffrey Zheng
E-mail: jxzheng@seas.upenn.edu
Biography:
Jeffrey received a Bachelor’s degree in Materials Science and Engineering from Cornell University in 2019 and currently a Ph.D. candidate at the University of Pennsylvania.
Research Interest:
His research involves studying nucleation and growth of ultra-thin ferroelectric materials film in order to develop correlations between interfacial interactions, process conditions, microstructure, and properties. He is co-advised by Prof. Eric Stach of MSE department and Prof. Troy Olsson of ESE department.

Cheng-Yu Chen
E-mail: cychen97@seas.upenn.edu
Biography:
Cheng-Yu received a Bachelor’s degreein in 2019 and a Master’s Degree in 2021 in Materials Science and Engineering at from the National Taiwan University. He joined the group at Penn in the Fall of 2022.
Research Interest:
During his Master’s studies, his research focused on reconstructing 3D microstructures by electron tomography using HAADF-STEM images. He will be researching the degradation processes of supported nanocatalyst systems through in-situ TEM imaging, combined with automated image analysis through machine learning methods.
