From Vapors to Films: Creating Smart Surfaces Via Vapor-Phase Depositions

From Vapors to Films: Creating Smart Surfaces via Vapor-Phase Depositions

Do Han Kim

Postdoctoral Associate

Chemical Engineering

Massachusetts Institute of Technology

Research Interests:

In techniques of vapor-phase depositions, multiple vapor-phase precursors are introduced into a vacuum chamber and react on a surface, generating thin solid films. In particular, initiated Chemical Vapor Deposition (iCVD) and Atomic Layer Deposition (ALD) are powerful techniques to deposit ultra-thin polymeric and inorganic films, respectively. In contrast to conventional solution-based deposition such as spin-casting, the key features of iCVD and ALD facilitate exceptionally conformal, defect-free coatings even on nano-porous structures and the precise thickness control in a molecular scale. In addition, the film properties are easily tuned by adjusting the feed gases and processing conditions. Therefore, those depositions open up the real nanoscale level which was even inaccessible in the past. As such, vapor-phase depositions satisfy strong demands for emerging multi-disciplinary fields in a nanoscale level; for example, energy, biotechnology, and electronics. In my research for Ph.D. and Postdoc., iCVD polymeric films are used to fabricate sub 10 nm patterns in conjunction with directed self-assembly (DSA) as a means to replace conventional photolithography. ALD films were also extensively exploited to engineer the interfaces inside dye-sensitized solar cells (DSSCs) and photoelectrochemical cells (PECs) for the efficient charge transfer kinetics.

Postdoctoral Project:

"Scalable Nano-manufacturing for Sub-10 nm Patterns Using initiated Chemical Vapor Deposition (iCVD) and Directed Self-Assembly (DSA)" under supervision of Karen K. Gleason, Chemical Engineering, Massachusetts Institute of Technology

Ph.D. Dissertation:

"Atomic Layer Deposition for Dye-Sensitized Solar Cells." Under Supervision of Gregory N. Parsons, Chemical and Biomolecular Engineering, North Carolina State University

Research Plans:

I would like to continue my research on vapor deposition techniques for polymer and inorganic films. Vapor-phase depositions, such as iCVD and ALD capable of coating ultra-thin, uniform, and pinhole-free films at low temperature, go beyond solution-based deposition for fundamental studies on surface chemistry as well as for high-performance catalysis, chemical sensing, energy, and bio- applications. For my future research as faculty, I conceive a novel and innovative deposition technique to create organic-inorganic hybrid films enabling to control the thickness and tailor the composition in a molecular level. The approach employing key features of iCVD and ALD facilitates to control the properties between two original phases or to bring up new properties with the precise thickness control on complex structures such as membranes, nanotubes, and particles. The applications of these materials in the fields of energy, optics, mechanics, biology, electronics and others are expected.

Teaching Experience:

I have had experiences as a TA for several years in experimental and lecturing classes related to core-classes of chemical engineering; process control, kinetics, transport phenomena lab. These experiences gave me insight on how teachers should encourage and involve students into understanding core and challenging classes of chemical engineering.

As an effort to be an effective teacher, I took intensive teaching classes and workshops during my Ph.D. program and post-doctoral training. Recently, I completed an intensive class aimed at improving teaching skill, provided by the MIT Teaching and Learning laboratory. I have mentored one undergraduate and two graduates so far, who successfully participated to publish two papers during doctoral and postdoctoral programs.

As outreach activities, I had the opportunity to participate in an annual state-wide outreach, 'Nanodays' coordinated by North Carolina State University, in which I demonstrated representative my results and samples of my research. To encourage K-12 students, I also volunteered in the National Mathematics and Science Competition organized by KSEA (Korean-American Scientists Engineers Association).

Patents

1. P. Hoertz, G. Parsons, Q. Peng, J. Liu, J. Glass, B. Kalanyan, D. H. Kim, M.D. Losego, L. Alibabaei, T. J. Meyer "Advanced semiconductor-conductor composite particle structures for solar energy conversion" U.S. patent, US20140261646 A1, 2014.

2. K. G. Henson, T. J. Meyer, G. N. Parsons, M. D. Losego, B. Kanlanyan, and D. H. Kim "Assemblies and methods of stabilization", U.S. patent, WO2014081921 A1, 2014.

Selected Publications

1.  N. Chen*, D. H. Kim*, P. Kovaick, M. Wang, H. Sojoudi, and K. K. Gleason, "CVD polymeric thin films for surface modification and device fabrication: recent progress" (2015) (submitted) *equally contributed

2. D. H. Kim, H. S. Suh, P. Moni., S. Xiong, L. C. Ocola, P. Nealey, and K. K. Gleason, ^" iCVD Top-coat for sub-10 nm patterning with directed self-assembly of block copolymer film" (2015) (in preparation)

3. B. Reeja-Jayan, P. Kovacik, R. Yang, H. Sojoudi, A. U. Katmis, D. H. Kim, C. D. Petruczok, X. Wang, A. Liu, and K. K. Gleason, "A Route towards sustainability through engineered polymeric interfaces", Advanced Materials Interfaces, 1, 1400117 (2014). (featured on frontispiece)

4. D. H. Kim, Q. Peng, M. D. Losego, and G. N. Parsons, "Atomic layer deposition for sensitized solar cells" (2015). (submitted)

5. D. H. Kim, S. E. Atanasov, P. Lemaire, K. Lee, and G. N. Parsons, "Platimum-free cathode for dye-sensitized solar cells using poly(3,4-ethylenedioxythiophene) (PEDOT) formed via oxidative molecular layer deposition" (2015), ACS Applied Materials & Interfaces, 17, 3866 (2015)

6. D. H. Kim, M. D. Losego, K. Hanson, L. Alibabaei, K. Lee, T. J. Meyer, and G. N. Parsons, "Stabilizing chromophores for dye-sensitized solar cells using multicomponent, sub-nanometer atomic layer deposition", Physical Chemistry Chemical Physics, 16 (18), 8615 (2014).

7. D. H. Kim, M. Woodroof, K. Lee, and G. N. Parsons, "Atomic layer deposition of high performance ultra-thin (< 10 nm) TiO₂ blocking layers for dye-sensitized solar cells", ChemSusChem, 6 (6), 1014, (2013). (featured on front cover)