Dong-Joon Yi
Ph.D. student, Department of Electronic Engineering, Hanyang University
Semiconductor Nanophotonics Laboratory | Advisor: Prof. Mun Seok Jeong
iverydj@hanyang.ac.kr | iver.ydj@gmail.com | iverydj.github.io | Google Scholar | github.com/iverydj
Research Interests
- Study physics in solid-state materials: how defects & quasiparticles affect their electrical and optical properties.
- Analyze defect states and local structure with transient spectroscopy (PICTS/DLTS) and tip-enhanced nanospectroscopy.
- Develop and apply interpretable machine learning to extract physically meaningful information from experimental data.
Education
Ph.D. student in Electronic Engineering (GPA 4.3 / 4.5)
Mar 2024 – present (expected Aug 2027)
Department of Electronic Engineering, Hanyang University
Seoul, Republic of Korea
- Semiconductor Nanophotonics Laboratory
- Advisor: Prof. Mun Seok Jeong
M.S. in Solid-state Physics (GPA 4.5 / 4.5)
Sep 2022 – Feb 2024
Department of Physics, Dongguk University
Seoul, Republic of Korea
- Advanced Physics on Electromaterial Laboratory
- Advisor: Prof. Kwun-Bum Chung
- Thesis: “Performance Control of InSnZnO/InGaZnO Multi-Channel-Layered Transistors with Defect Analysis of Amorphous Oxide Semiconductors”
B.S. in Physics (GPA 4.2 / 4.5)
Mar 2016 – Aug 2022
Department of Physics, Dongguk University
Seoul, Republic of Korea
- Undergraduate researcher, Advanced Physics on Electromaterial Laboratory (Jul 2021 – Aug 2022)
- Military service, Republic of Korea (Jun 2019 – Apr 2021)
Research Fellowship
Principal Investigator
Sep 2025 – Aug 2027
Doctoral Research Fellowship, Basic Science Research Program, National Research Foundation of Korea (NRF)
KRW 50 million (total, 2 years)
- Project: “Deep-Level Transient Spectroscopy and Nanospectroscopy for Ultrafine Defect Analysis Using Explainable AI in 2D Quantum Semiconductors”
- Funded by the Ministry of Education through the National Research Foundation of Korea (NRF).
Research
1. Defect Physics in Solid-State Materials
- Defect states in oxide semiconductors and their relation to device characteristics and stability. (Surf. Interfaces 2025; Sci. Rep. 2023; IEEE Trans. Electron Devices 2024; ACS Appl. Electron. Mater. 2024)
- Defect-mediated control of carrier type in 2D semiconductors for complementary devices.
- Exciton modulation in 2D semiconductors through coupling to plasmonic nanostructures.
2. Defect and Nanoscale Spectroscopy
- Transient spectroscopy (PICTS/DLTS) of defect states in 2D semiconductors.
- Nanoscale mapping of defects and strain in 2D materials by tip-enhanced spectroscopy.
- Electromagnetic simulation of near-field enhancement in tip-enhanced spectroscopy. (Mater. Des. 2026)
3. Interpretable AI for Science
- Interpretable machine learning relating Raman spectra to electrical properties.
- Deep-learning noise reduction of experimental spectra that preserves spectral parameters.
- Simulation of analog in-memory learning based on measured synaptic characteristics of ferroelectric InSe neuromorphic devices.
- Numerical precision and the reliability of scientific machine learning. (ICML 2026)
- Review of the physical interpretability of machine-learning analysis in spectroscopy.
Publications
First†, Corresponding*
- T. G. Weldemhret†, D.-J. Yi†, K. Jeong, K.-B. Chung*, “Evaluation of the high mobility and stability of InGaZnO/InSnZnO bilayer thin-film transistors via quantitative defect analysis,” Surfaces and Interfaces, 71, 106870 (2025), DOI:10.1016/j.surfin.2025.106870
- S. Bang†, D. Choi†, H. C. Suh†, C. Lee, S. Lim, Y. J. Yu, D. H. Kim, S. H. Kim, J. Yoo, T. Kim, D. Lee, H. J. Park, U. J. Kim, D.-J. Yi, H. Oh*, D.-W. Kim*, M. S. Jeong*, “Ultrawide Charge-Trap Memory Window and Photoinduced Synaptic Behavior in p-Channel Amorphous Oxide Semiconductors,” Small, e74713 (2026), DOI:10.1002/smll.74713
- Y. Cho†, J. Yoo†, S. Yang, D.-J. Yi, S. M. Lee, M. S. Jeong*, J. Choo*, “Position: Significant impact of numerical precision in scientific machine learning,” International Conference on Machine Learning (ICML), Position Paper Track, PMLR 306 (2026), PDF
- H. C. Suh†, T. Kim†, D.-J. Yi, D. H. Kim, S. H. Kim, J. Yoo, S. Bang, D. Lee, J. H. Kim, Y. S. Won, K. K. Kim, M. S. Jeong*, “Prediction and assessment of nanoprobe for tip-enhanced Raman spectroscopy: Data-driven artificial intelligence approach,” Materials & Design, 266, 116066 (2026), DOI:10.1016/j.matdes.2026.116066
- S. Bang†, C. Lee†, D. Choi, D. Y. Park, D. H. Kim, D. Lee, D.-J. Yi, J. Song, S. J. Yun, D.-W. Kim*, M. S. Jeong*, “High Performance P-Channel Transistor Based on Amorphous Tellurium Trioxide,” Advanced Materials, 37, 2504948 (2025), DOI:10.1002/adma.202504948
- D. H. Kim†, J. Yoo, H. C. Suh, Y. S. Won, S. H. Kim, D.-J. Yi, B. G. Jeong, C. Lee, D. Lee, K. K. Kim, S. M. Lee, E. K. Koh, M. S. Jeong*, “Anomalous phonon softening with inherent strain in wrinkled monolayer WSe2,” Advanced Materials, 37, 2419414 (2025), DOI:10.1002/adma.202419414
- K. Jeong†, D. Y. Shin, J.-M. Park, D.-J. Yi, H. Hong, H.-S. Kim*, K.-B. Chung*, “Noncontact Monitoring and Imaging of the Operation and Performance of Thin-Film Field-Effect Transistors,” Advanced Science, 12, 2407923 (2025), DOI:10.1002/advs.202407923
- A. Song†, M. J. Kim†, D.-J. Yi, S. Kwon, D.-W. Kim, S. Kim, J.-H. Bae, S. Park, Y. S. Rim*, K.-S. Jeong*, K.-B. Chung*, “Control of sensitivity in metal oxide electrolyte gated field-effect transistor-based glucose sensor by electronegativity modulation,” Scientific Reports, 14, 27251 (2024), DOI:10.1038/s41598-024-76885-x
- H. Hong†, M. J. Kim†, D.-J. Yi, D. Y. Shin, Y.-K. Moon, K.-S. Son, J. H. Lim, K. Jeong*, K.-B. Chung*, “Quantitative dynamic evolution of unoccupied states in hydrogen diffused InGaZnSnO TFT under positive bias temperature stress,” ACS Applied Electronic Materials, 6, 7584–7590 (2024), DOI:10.1021/acsaelm.4c01430
- H. Hong†, D.-J. Yi, Y.-K. Moon, K.-S. Son, J. H. Lim, K. Jeong, K.-B. Chung*, “Double gated a-InGaZnO TFT properties based on quantitative defect analysis and computational modeling,” IEEE Transactions on Electron Devices, 71(2), 1097–1101 (2024), DOI:10.1109/TED.2023.3347503
- H. Hong†, M. J. Kim, D.-J. Yi, Y.-K. Moon, K.-S. Son, J. H. Lim, K. Jeong*, K.-B. Chung*, “Quantitative analysis of defect states in InGaZnO within 2 eV below the conduction band via photo-induced current transient spectroscopy,” Scientific Reports, 13, 13407 (2023), DOI:10.1038/s41598-023-40162-0
In Preparation
- D.-J. Yi† et al., “Predicting the electrical conductivity of carbon-nanotube films from Raman spectra with interpretable deep learning,” in preparation.
- D.-J. Yi† et al., “Carrier-type conversion of two-dimensional Mo1−xWxTe2 for complementary inverters,” in preparation.
- D.-J. Yi† et al., “Physics-preserving recovery of noisy Raman spectra of two-dimensional materials with deep learning,” in preparation.
- D.-J. Yi† et al., “Deep-learning classification of bacterial SERS spectra on metal–organic framework substrates,” in preparation.
- D.-J. Yi† et al., “AI-driven spectroscopy with explainability for physical interpretation,” Invited review, in preparation.
- …, D.-J. Yi, …, “Ferroelectric InSe synaptic devices for analog in-memory learning,” in preparation.
Patents
- K.-B. Chung, K. Jeong, D.-J. Yi. “Device Array Analysis Method and Analysis Apparatus Therefor.” Korean Patent, 10-2892259 (granted 2025); U.S. Patent Application 18/771,046 (pending). Assignee: Industry Academic Cooperation Foundation of Dongguk University.
- K.-B. Chung, K. Jeong, D.-J. Yi, H. Hong. “Method of Confirming Performance of Secondary Battery and Apparatus of Performing the Same.” Korean Patent Application, 10-2023-0161220. Assignee: Industry Academic Cooperation Foundation of Dongguk University.
Scholarships & Awards
| 2026 | Outstanding Presentation Award, KPS Spring Meeting, Oral Session | Korean Physical Society |
| 2025 | Graduate Student Research Competition (HY-BrainKorea G3), 2nd Place | Hanyang University |
| 2024 | IC-PBL Graduate Championship, 3rd Place | Hanyang University |
| 2022, 2023 | Physics Department Alumni Scholarship | Dongguk University |
| 2022, 2023 | Dongguk Future Talent Scholarship | Dongguk University |
Skills
| Spectroscopy | Optical spectroscopy (Raman, photoluminescence, ellipsometry), tip-enhanced nanospectroscopy, X-ray photoelectron spectroscopy |
|---|---|
| Scanning Probe Microscopy | Atomic force microscopy (AFM), Kelvin probe force microscopy (KPFM), piezoresponse force microscopy (PFM) |
| Defect & Electrical | Deep-level transient spectroscopy (DLTS), photo-induced current transient spectroscopy (PICTS), I–V |
| Machine Learning | Deep learning for scientific data, explainable AI |
| Simulation | Finite-difference time-domain (FDTD) simulation, including a self-developed CUDA-accelerated, multi-GPU fork of Meep |
| Fabrication | Photolithography, magnetron sputtering |