About

About

Jinseok Ryu, PhD

[Email] jinseuk56@gmail.com
[Email] jinseuk56@snu.ac.kr
[Github] https://github.com/jinseuk56
[LinkedIn] https://www.linkedin.com/in/j-ryu/
[ORCID] https://orcid.org/0000-0002-9558-3469

🔸Summary of Qualifications

  • A unique background combining advanced transmission electron microscopy and the development of analysis methods using machine learning and deep learning for materials characterization.
  • Successfully developed and published multiple open-source, data-driven analysis pipelines to solve critical materials challenges, including 3D observation, characterization of amorphous structures, and elucidation of the structure-property relationships in photovoltaic materials, batteries, catalytic nanoparticles, and semiconductors.

🔸Education

PhD | Mar 1, 2017 → Aug 29, 2022

Combined MS/PhD Course
Advisor: Prof. Miyoung Kim
Materials Science and Engineering
Seoul National University

BS | Mar 1, 2009 → Aug 28, 2015

Materials Science and Engineering
Seoul National University

🔸Professional Experience

Research Associate Professor | Mar 1, 2026 → Present

Research Institute of Advanced Materials (RIAM)
Seoul National Unversity (Seoul, South Korea)

Postdoctoral Research Associate | Mar 4, 2024 → Jan 30, 2026

electron Physical Science Imaging Centre (ePSIC)
Diamond Light Source (Didcot, United Kingdom)
Funded by the InFUSE Prosperity Partnership

Postdoctoral Research Associate | Sep 1, 2022 → Feb 29, 2024

Research Institute of Advanced Materials (RIAM)
Seoul National University (Seoul, South Korea)

Semiconductor Engineer | Jul 1, 2015 → Jul 19, 2016

SK Hynix (Icheon-si, Gyeonggi-do, South Korea)

Military Service | Apr 26, 2010 → May 6, 2012

Hornorable Discharge
Republic of Korea Air Force (Seoul, South Korea)

🔸Teaching Experience

28th TEM Workshop | Jul 20, 2023

Korean Society of Microscopy
Lecture Title: Machine learning in TEM analysis: basics and applications

27th TEM Workshop | Jul 28, 2022 → Jul 29, 2022

Korean Society of Microscopy
Lecture Title: STEM-derived multi-dimensional data processing in Python-integrated GMS3

Fundamentals of Computer Science | Sep 1, 2020 → Dec 31, 2020

Department of Materials Science and Engineering
Seoul National University

🔸Skills

(S)TEM Experiment and Analysis

  • Capable of acquiring microscopy data using (Cs-corrected) TEMs including ARM300CF, ARM200CF, JEM-2100F (JEOL), Themis Z and Tecnai F20 (Thermo Fisher)
  • Experienced in advanced (S)TEM imaging and spectroscopy experiments, including 4-dimensional STEM (4D-STEM), differential phase contrast STEM (DPC-STEM) and electron energy loss spectroscopy (EELS)
  • Experienced in analyzing the structure-property relationship of materials through (S)TEM
    • Ion-battery electrode materials (solid electrolyte interface), photovoltaic materials (lead halide perovskites), catalytic/plasmonic nanoparticles (gold, titanium oxide), amorphous materials (IGZO, gallium oxide, carbon), transition metal oxide-based memories (tantalum/hafnium oxides), light emitting materials (gallium nitride)
    • STEM/EDS/EELS tomography
    • 4D-STEM analysis (virtual imaging/RDF/FEM/DPC/ptychography)
    • Atomic structure & structural defect analysis including amorphous structure analysis [radial distribution function (RDF) & fluctuation electron microscopy (FEM)]
    • in-situ TEM experiments and analysis
    • Electronic structure & quantitative chemical analysis through EELS and EDS

Methodology Development for Microscopy Data Analysis

  • Experienced in programming using Python language and DM scripting for (S)TEM analysis (Link)
    • Developing programs for feature extraction from microscopy-derived big datasets using various machine learning algorithms, including supervised/unsupervised learning based on deep neural networks (Link)
    • Developing programs for electron/EELS tomography (Link)
    • Developing programs for 4D-STEM data processing and analysis (Link)
  • Experienced in hardware communication and measurement automation (Link)
    • Developing a concurrent acquisition system of different modalities (4DSTEM and EDX)
    • Developing an automated measurement system

🔸Publication

(†: first author or co-first authors, *: corresponding author)

  • Lee, S.†, Kim, S.†, Ryu, J.†, Lee, J., Hong, J., Kim, J. E., Cha, J.-Y., Shin, Y., Kwon, D., Yoon, J. H., Park, M. H., Kim, M., Lee, S.-Y. (2026). In situ transmission electron microscopy visualization of electric-field-induced phase transitions at the morphotropic phase boundary in Hf0.5Zr0.5O2. ACS Nano. https://doi.org/10.1021/acsnano.5c15856
  • Zeng, Q.†, Zhao, Y., Park, S., Zhou, H., Shim, H.-J., Li, T., Ryu, J., Sung, M.-J., Chua, X. W., Yoon, E., Lewis, B. A. I., Woo, S.-J., Forzatti, M., Kim, M. J., Kim, E. A., Dai, L., Jang, J., Tang, Y., Kweon, J. J.,…Lee, T.-W.* (2026). A hierarchical shell locks and stabilizes perovskite nanocrystals with near-unity quantum yield. Science, 391(6782), 6782. https://doi.org/10.1126/science.ady1370.
  • Topping, N.†, Bridges, J. C., Hicks, L. J., Petera, L., Allen, C. S., Ryu, J., Hopkinson, D. G., Danaie, M., Blase, L., Willcocks, F. M., Douglas, G., Changela, H. G., Noguchi, T., Matsumoto, T., & Miyake, A. (2025). Sulfur‐bearing serpentine in carbonaceous chondrites. *Meteoritics & Planetary Science. https://doi.org/10.1111/maps.70069
  • Hein, P.†, Romstadt, T., Draber, F., Ryu, J., Böger, T., Falkenstein, A., Kim, M., & Martin, M.* (2025). Variable‐range hopping conduction in amorphous, non‐stoichiometric gallium oxide. Advanced Electronic Materials, 11(4). https://doi.org/10.1002/aelm.202400407
  • Kim, I.†, Ryu, J., Lee, E., Lee, S., Lee, S., Suh, W., Lee, J., Kim, M., Oh, H. s., & Yi, G.-C.* (2024). Molecular beam epitaxial In2Te3 electronic devices. NPG Asia Materials, 16(1). https://doi.org/10.1038/s41427-024-00578-0
  • Jo, J.†, Ryu, J.†, Huh, J. H., Kim, H., Seo, D. H., Lee, J., Kwon, M., Lee, S., Nam, K. T., & Kim, M.* (2024). Direct three-dimensional observation of the plasmonic near-fields of a nanoparticle with circular dichroism. ACS Nano, 18(47), 32769-32780. https://doi.org/10.1021/acsnano.4c10677
  • Park, S.†, Jang, T.†, Choi, S.†, Lee, Y. H., Cho, K. H., Lee, M. Y., Seo, H., Lim, H. K., Kim, Y., Ryu, J., Im, S. W., Kim, M. G., Park, J. S., Kim, M., Jin, K., Kim, S. H., Park, G. S., Kim, H., & Nam, K. T.* (2023). Iridium-cooperated, symmetry-broken manganese oxide nanocatalyst for water oxidation. Journal of the American Chemical Society , 145(49), 26632-26644. https://doi.org/10.1021/jacs.3c07411
  • Kim, S.†, Kim, U.-g., Ryu, J., Kim, D., Kim, M., Joo, Y.-C., & Lee, S.-Y.* (2023). Boron-doped amorphous carbon deposited by DC sputtering for a hardmask: Microstructure and dry etching properties. Applied Surface Science, 637. https://doi.org/10.1016/j.apsusc.2023.157895
  • Oh, J.†, Lee, S. Y., Kim, H., Ryu, J., Gil, B., Lee, J., & Kim, M.* (2022). Overcharge-induced phase heterogeneity and resultant twin-like layer deformation in lithium cobalt oxide cathode for lithium-ion batteries. Advanced Science, 9(32), e2203639. https://doi.org/10.1002/advs.202203639
  • Yoon, S.†, Seo, H., Jin, K., Kim, H. G., Lee, S. Y., Jo, J., Cho, K. H., Ryu, J., Yoon, A., Kim, Y. W., Zuo, J. M., Kwon, Y. K., Nam, K. T., & Kim, M.* (2022). Atomic reconstruction and oxygen evolution reaction of Mn3O4 nanoparticles. Journal of the Physical Chemistry Letters, 13(35), 8336-8343. https://doi.org/10.1021/acs.jpclett.2c01638
  • Ryu, J.†, Lee, S.†, Kim, S., Joo, Y.-C., & Kim, M.* (2022). Correlative study between the local atomic and electronic structures of amorphous carbon materials via 4D-STEM and STEM-EELS. Applied Physics Letters, 121(4). https://doi.org/10.1063/5.0100925
  • Ryu, J.†, Kim, H., Kim, R. M., Kim, S., Jo, J., Lee, S., Nam, K. T., Joo, Y. C., Yi, G. C., Lee, J., & Kim, M.* (2021). Dimensionality reduction and unsupervised clustering for EELS-SI. Ultramicroscopy, 231, 113314. https://doi.org/10.1016/j.ultramic.2021.113314

🔸Conference & Award

(†: presenter, *: corresponding author)

  • (Oral Presentation) Ryu, J.†, AA. Sheader, M. Danaie, DG. Hopkinson, KE. MacArthur, NK. Noel, and CS. Allen, “Concurrent Acquisition of Many 4DSTEM-EDX Data Pairs and Effective Data Analysis Workflow for Beam-sensitive Materials”, EMAG 2025*, Manchester, United Kingdom (2025)
  • (Oral Presentation) Ryu, J.†, AA. Sheader, M. Danaie, DG. Hopkinson, KE. MacArthur, NK. Noel, and CS. Allen, “Automation of Simultaneous 4DSTEM-EDX Acquisition and Data Analysis for Beam-sensitive Materials”, 13th Asia Pacific Microscopy Congress*, Brisbane, Queensland, Australia (2025)
  • (Oral Presentation) Lee, S.†, J. Ryu, S. Lee, P. Hein, M. Martin, Y. Kim, M. Kim, “Mapping Electrical Properties Using STEM-EBIC for Electric Field-Induced Resistance Changes in Amorphous Gallium Oxide”, 13th Asia Pacific Microscopy Congress*, Brisbane, Queensland, Australia (2025)
  • (Oral Presentation) Lee, S.†, J. Ryu, H. Philipp, M. Martin, M. Kim, “In-Situ Biasing TEM Analysis of Resistive Switching in Amorphous GaOx for Next-Generation Memory Applications”, 2024 Materials Research Society Fall Meeting*, Boston, Massachusetts, United States (2024)
  • (Oral Presentation) Chang, Y.†, J. Ryu, H. Yoo, H. N. Han, M. Kim, “Ptychography Optimization for Atomic Analysis of Bending Mode in Bilayer Transition Metal Dichalcogenide Translational Motion”, 17th European Microscopy Congress*, Copenhagen, Denmark (2024)
  • (Oral Presentation) Ryu, J.†, J. Jo, H. Kim, K. T. Nam, M. Kim, “GPU-based fast reconstruction and DL-based feature extraction for EELS tomography”, 20th International Microscopy Congress*, Busan, South Korea (2023)
  • (Invited talk) Ryu, J.† (on behalf of Prof. Miyoung Kim), G. Kim, S. Lee, M. Kim, “Exploring ionic migration and structural evolution in dielectric devices”, 20th International Microscopy Congress*, Busan, South Korea (2023)
  • (Oral Presentation) Ryu, J.†, S. Lee, S. Kim, Y.-C. Joo, M. Kim, “A comprehensive nanoscale characterization of amorphous carbon films through STEM-EELS and 4D-STEM”, 20th International Microscopy Congress*, Busan, South Korea (2023)
  • (Oral Presentation) Lee, S.†, J. Ryu., S. Y. kim, G. Park, S. D. Hyun, S. Y. Yang, M. Kim, “Revealing the Resistive Switching Mechanism in Transition Metal Oxide Film Using In-situ Biasing TEM”, 20th International Microscopy Congress*, Busan, South Korea (2023)
  • (Poster presentation) Jo, J.†, J. Ryu., M. Kim, “Unraveling surface plasmon peak splitting in silver nanoparticles decorated on ZnO nanorods via monochromated STEM EELS tomography”, 20th International Microscopy Congress*, Busan, South Korea (2023)
  • (Invited talk) Ryu, J.†, J. Jo, S. Lee, M. Kim, “Unsupervised learning strategies for extracting features from STEM-derived multi-dimensional data”, 2023 Korea Society of Microscopy Spring Conference, Daejeon, South Korea (2023)
  • (Poster presentation) Ryu, J.†, S. Lee, S. Kim, I. Yoo, Y.-C. Joo, M. Kim, “A machine-learning approach to characterization of amorphous materials with EELS-SI and 4D-STEM”, 2022 Materials Research Society Spring Meeting*, Hawaii, United States (2022)
  • (Poster presentation) Jo, J.†, K. MacArthur, J. Ryu, H. Kim, S. Collins, K. Müller-Caspary, K. Nam, M. Kim, R. E. Dunin-Borkowski, “Three-dimensional characterization of nanoparticles with simultaneously acquired bright-field, dark-field, and secondary electron signals in STEM”, PICO 2021, Virtual conference,* (2021)
  • (Oral presentation) Ryu, J., J. Jo, J. Lee†, M. Kim, “Feature extraction and reconstruction of electron energy loss spectroscopy by non-negative matrix factorization”, 12th Asia Pacific Microscopy Congress*, Hyderabad, India (2020)
  • Excellence Prize, Best Paper Award, Seoul National University & Samsung Electronics R&DB Foundation, South Korea (2021)