Jiwoong Park Professor of Chemistry

Professor (2016.7- ) Department of Chemistry and Institute of Molecular Engineering, University of Chicago

Assistant Professor (2006 –2012), Associate Professor (2012 –2016.6) Department of Chemistry and Chemical Biology, Cornell University

Rowland Junior Fellow (2003- 2006) Rowland Institute at Harvard University, Harvard University

Ph. D. in Physics (2003) University of California, Berkeley

B. S. in Physics (1996) Seoul National University, South Korea

Accolades

Frontier Research Scientist, Korean Academy of Science and Technology (2011)
Alfred P. Sloan Research Fellowship (2010)
Presidential Early Career Award for Scientists and Engineers (2009)
National Science Foundation CAREER award (2008)
Rowland Junior Fellow, Harvard University (2003-2006)
Graduate Research Fellow, Korea Foundation for Advanced Studies (1998-2003)
Robert and Susan Katz Fellow, UC Berkeley (1998)
Undergraduate Research Fellow, Korea Foundation for Advanced Studies (1994-1996)
Gold medalist, International Mathematics Olympiad, Russia (1992)

E-MAIL: jpark@cornell.edu

RESEARCH INTERESTS:

Our research focuses on the science and application of nanomaterials. We understand and control the growth and physical properties of individual nanostructures, and to this end, we develop new characterization methods, or “new eyes”, sensitive to their structural, chemical, and physical properties that could provide fundamentally new insights and control. Our research in recent years has led to novel synthesis and characterization methods for low-dimensional nanostructures, 2-dimensional ones in particular, which led to numerous observations of novel electrical, optical and optoelectronic phenomena. Our current research interests and past research achievements in two key research areas are as follows:

Atomically thin integrated circuitry: Our research group focuses on advancing the growth, characterization and application of 2D materials, including electrically conducting graphene, insulating hBN and semiconducting transition metal dichalcogenides. We, together with our collaborators, reported the first atom-resolution imaging of individual grain boundaries in chemically grown graphene using scanning transmission electron microscope (TEM) (Nature, 469, 389-392 (2011)), which revealed tightly knit hexagon-heptagon (5-7) defect structures at the grain boundaries. We investigated the electrical properties of individual grain boundaries for the first time (Science, 336, 1143-1146 (2012)), reporting that, unlike silicon, well-grown polycrystalline graphene films could have electrical properties comparable to those of single crystalline graphene. We further developed a method for precise spatial control over the electrical properties in atomically thin materials (Nature, 488, 627-632 (2012)), a key capability enabling the production of integrated circuitry. Most recently, we reported the MOCVD (metal-organic chemical vapor deposition) growth of wafer-scale three-atom-thick semiconductor films with high mobility for the first time (Nature, 520, 656-660 (2015)). Altogether, our results represent an important step towards developing atomically-thin integrated circuitry and enable the fabrication of electrically isolated active and passive elements embedded in continuous, one- and few-atom-thick sheets, which could further be manipulated and stacked to form complex devices at the ultimate thickness limit.

Electrical and optoelectronic characterization of low-dimensional nanostructures: We develop a fundamental understanding of the unique physical properties in low-dimensional materials. Our group research has led to numerous discoveries of novel electrical, optical, and optoelectronic properties of low-dimensional nanostructures, including multiple exciton generation* (Science 325, 1367-1371 (2009)), optical intertube coupling (Nature Nanotech. 6, 51-56 (2011)), and the photothermal current effect (Nature Nanotech. 4, 108-113 (2009)) in carbon nanotubes, and supercollision cooling in graphene photodetectors* (Nature Phys., 9, 103-108 (2013)). Most recently, we reported the valley Hall effect in MoS2 transistors* (Science, 344, 1489-1492 (2014)) (* in collaboration with the McEuen group at Cornell University). These results will allow the developments of various advanced devices, such as highly efficient solar cells, ultrasensitive infrared bolometric detectors, and novel valleytronic and spintronic devices.

 

Selected References:

K. Kang, S. Xie, L. Huang, Y. Han, P. Y. Huang, K. F. Mak, C.-J. Kim, D. A. Muller, and J. Park, “High-performance three-atom-thick semiconducting films with wafer scale homogeneity,” Nature, 520, 656-660 (2015).

K. F. Mak, K. L. McGill, J. Park and P. L. McEuen, “The Valley Hall Effect in MoS2 Transistors”, Science, 344, 1489-1492 (2014).

M. W. Graham, S. Shi, D. C. Ralph, J. Park and P. L. McEuen, “Photocurrent Measurements of Supercollision Cooling in Graphene”, Nature Physics, 9, 103-108 (2013).

M. P. Levendorf, C.-J. Kim, L. Brown, P. Y. Huang, R. W. Havener, D. A. Muller, and J. Park, “Graphene and Boron Nitride Lateral Heterostructures for Atomically Thin Circuitry”, Nature, 488, 627-632 (2012).

A. W. Tsen, L. Brown, M. P. Levendorf, F. Ghahari, P. Y. Huang, C. S. Ruiz-Vargas, R. W. Havener, D. A. Muller, P. Kim, and J. Park, "Tailoring Electrical Transport across Grain Boundaries in Polycrystalline Graphene", Science, 336, 1143-1146 (2012).

P. Y. Huang, C. S. Ruiz-Vargas, A. M. van der Zande, W. S. Whitney, M. P. Levendorf, J. W. Kevek, S. Garg, J. S. Alden, C. J. Hustedt, Y. Zhu, J. Park, P. L. McEuen, D. A. Muller, “Grains and Grain Boundaries in Single-Layer Graphene Atomic Patchwork Quilts,” Nature 469, 389-392 (2011).

D. Y. Joh, J. Kinder, L. H. Herman, S.-Y. Ju, M. A. Segal, J. N. Johnson, G. K. L. Chan, and J. Park, “Single walled carbon nanotubes as excitonic optical wires”, Nature Nanotechnology 6, 51-56 (2011).

N. M. Gabor, Z. Zhong, K. Bosnick, J. Park, and P. L. McEuen. “Extremely efficient multiple electron-hole pair generation in carbon nanotube photodiodes”, Science 325, 1367-1371 (2009).

W. Tsen, L.A.K. Donev, H. Kurt, L.H. Herman, and J. Park “Imaging electrical conductance of individual carbon nanotubes with photothermal current microscopy”, Nature Nanotechnology 4, 108-113 (2009).

J. Park, A.N. Pasupathy, J. Goldsmith, C. Chang, Y. Yaish, J. Petta, M. Rinkoski, J. Sethna, H.D. Abruna, P.L. McEuen, and D.C. Ralph “Coulomb blockade and the Kondo effect in single-atom transistors”, Nature 417, 722-725 (2002).