Seungjin Lee

Research & Development Experience:

Synthesized various 2D materials (Graphene, hBN, TMDCs) using Chemical Vapor Deposition (CVD). Performed comprehensive analysis and evaluation using advanced characterization techniques including Microscopy (Optical Microscopy, Scanning Electron Microscopy, Atomic Force Microscopy, Transmission Electron Microscopy) and Spectroscopy (Raman Spectroscopy, X-ray Photoelectron Spectroscopy, Energy-dispersive X-ray Spectroscopy), as well as Diffraction (X-ray Diffraction, Electron Backscatter Diffraction). My work further involved applying these synthesized high-quality 2D materials as active components in electronic devices. This included patterning using photolithography, depositing metal electrodes via sputtering and thermal evaporation, and evaluating device performance using a probe station.

Specifically, I focused on the application of hBN thin films, a promising insulating material, by directly synthesizing and controlling their thickness. I patterned and deposited electrodes for memristors and assessed device durability and volatility by extracting variability, endurance, and retention data from I-V curve measurements.

Technical & Management Skills:

I gained extensive experience with a variety of advanced equipment. I served as a manager for five CVD systems, a Scanning Electron Microscope (SEM), a Universal Testing Machine (UTM), and the chemistry lab. My responsibilities included equipment design, setup, and maintenance, as well as troubleshooting a diverse range of issues, such as vacuum degradation due to aging pump sealing tips, line blockages caused by abnormal precursor deposition, and check valve malfunctions resulting from excessive backflow.

Given that approximately 50% of users were non-native English speakers, effective English communication was essential, allowing me to develop strong proficiency in English communication.

Publication Achievements:

• Lead author paper on single-crystal monolayer graphene published in ASCT.
• Fourth author paper on elucidating the mechanism of single-crystal substrates published in Nat. Comm.
• Lead author paper on direct growth of graphene on various perovskite substrates submitted to JACS.
• Co-author paper on violet phosphorus synthesis submitted to Adv. Mater.
• Co-author paper on MoS2 and hBN-based QW EL currently in preparation.

Collaborations Based on Research Achievements:

Successfully synthesized high-quality single-crystal monolayer graphene and hexagonal boron nitride (hBN) thin films, leading to collaboration requests from various external research institutions for joint studies.

• University of Virginia: Observed hybrid charge transfer excitons by utilizing single-crystal monolayer hBN as a wide-bandgap barrier between GaN and 2D materials.
• Northwestern University: Grown borophene using single-crystal monolayer hBN thin films as a growth platform.
• University of California, Berkeley: Synthesized GaN by stacking single-crystal monolayer hBN thin films on LiGaO2, followed by Atomic Layer Deposition (ALD) of Al2O3 and subsequent heat treatment.
• POSTECH: Established an hBN analysis method using Second Harmonic Generation.
• POSTECH: Established a molecular structure analysis method for single point defects in hBN via tip-enhanced Raman scattering (TERS).
• POSTECH: Observed single quantum light sources based on hBN defects induced by gaps between bow-ties.
• Sungkyunkwan University: Direct growth of graphene on various perovskite substrates (submitted to JACS).
• Sungkyunkwan University: Grown SiC using single-crystal monolayer hBN thin films as a growth platform.
• Kyung Hee University: Observed device characteristics of moiré structures by stacking different single-crystal monolayer hBN thin films and performed KPFM analysis of twisted hBN samples.

Participation in Project Proposals and Presentations:

• Korea-Germany Joint Research Project
• Korea-EU Joint Research Project
• Fab Advancement Project
• Basic Research Lab Project