Research Topics

Advanced Thin-Film Electronics & Energy Materials

I am a passionate Ph.D candidate specializing in stretchable organic electronics and energy materials, with a focus on developing innovative solutions for next-generation electronic devices with synchrotron based X-ray analysis.

1. Stretchable & Deformable TFTs based on Conjugated Polymers:

- Designed novel materials like azide photocrosslinkers to improve the stretchability of semiconducting polymers.
- Developed plasticizing molecular additives for deformable polymer electronics.
- Ref) "Tailoring Polymer Backbone Rigidity with Plasticizing Additives for Deformable Transistors " (2025, Adv. Funct. Mater.).
- Ref) "Structural Insights into Conjugated Polymers for Stretchable Organic Transistors" (2024, Chem. Mater.).
- Ref) "Designing a Length‐Modulated Azide Photocrosslinker to Improve the Stretchability of Semiconducting Polymers" (2023, Adv. Funct. Mater.).

2. Advanced Conjugated Networks Designs:

- Synthesized high-performance semiconducting conjugated polymers with controlled regiochemistry and tuned chain planarity for organic transistors.
- Novel amromatic conjugated networks with extended chain dimensions from 1D (chain) to 2D (plain) for efficient charge transport pathway.
- Ref) "Hydrophenazine-linked two-dimensional ladder-type crystalline fused aromatic network with high charge transport" (2023, Chem)
- Ref) "Solution-Processable Semiconducting Conjugated Planar Network" (2022, ACS Appl. Mater. Interfaces.)
- Ref) "Unidirectional Macroscopic Alignment of Chlorobenzo [c]‐[1, 2, 5] thiadiazole‐Based Semiconducting Copolymers with Controlled Regiochemistry" (2021, Adv. Electron. Mater.).

3. (Electro)chemical Ion Diffusion in Conjugated Polymers and their Charge Transport:

- Investigated the role of side chain lengths in conjugated polymers to improve nonvolatile characteristics for neuromorphic computing and artificial synapse devices.
- Polarity transition from p-type conjugated polymer to n-type with sequential doping treatment to switching the majority carrier.
- Ref) "Accompanying Structural Transformations in Polarity Switching of Heavily Doped Conjugated Polymers " (2025, Adv. Mater.).
- Ref) "Unveiling the Role of Side Chain for Improving Nonvolatile Characteristics of Conjugated Polymers-Based Artificial Synapse" (2024, Adv. Sci.).

4. Assembly & Packing in Organic Solar Cells (OSCs):

- Achieved groundbreaking efficiencies of up to near '20%' in binary OSCs through advanced phase regulation techniques and HTL doping process.
- Explored molecular additives and donor-acceptor engineering to enhance charge carrier dynamics and device performance.
- Ref) "Hole-selective-molecule doping improves the layer thickness tolerance of PEDOT: PSS for efficient organic solar cells"  (2024, eScience)
- Ref) "Impact of Intermolecular Interactions between Halogenated Volatile Solid Additives and the Nonfullerene Acceptor in Organic Solar Cells"  (2023, Adv. Funct. Mater.)
- Ref) "Vertical Phase Regulation with 1,3,5‐Tribromobenzene Leads to 18.5% Efficiency Binary Organic Solar Cells" (2023, Adv. Sci.).
- Ref) "Charge Carrier Dynamics in Planar Heterojunction Organic Solar Cells"  (2023, Solar RRL)

<Skills and Expertise>

- Device Fabrication: Extensive experience in fabricating  thin-film transistors and stretchable electronics. (Photolithography, thin-film deposition, solution processing)

- Systematic Design: Proficient in designing systems of the synthesized conjugated polymers tailored for specific electronic applications

- Advanced Characterization:

  - X-ray techniques such as small-angle scattering (SAXS), spectroscopy (UPS, XPS, NEXAFS, UV-Vis-NIR, RAMAN, FT-IR), and microscopy (w/ Polarizer) for structural analysis.

  - Multiscale analyses of strain-enhanced charge transport in semiconducting polymers.

- Collaborative Research: Worked on interdisciplinary projects involving perovskite solar cells, bioelectronics, and photodiodes.

<Notable Achievements>

- Published multiple first-author papers in top-tier journals like *Advanced Materials*, *Chem*, *Advanced Functional Materials*, *Chemistry of Materials*, and *Advanced Science*.

- Contributed to collaborative works achieving high power conversion efficiencies near 20% PCE (2024, Nat. Commun.) and high-mass loading Zn-batteries (2024, Nat. Commun.).

- Developed innovative strategies for stretchable electronics, including length-modulated crosslinkers and plasticizing molecular additives with persistence length modulation.

- Python-based Vibe coding for data analysis (https://github.com/sein3449)

<Future Vision>

My research is driven by the goal of transforming organic materials into practical, high-performance solutions for energy harvesting, flexible electronics, and neuromorphic computing. I aim to bridge the gap between fundamental science and real-world applications through innovative material design and engineering. Let’s connect to explore collaborations or discuss how my expertise can contribute to advancing your projects!