What we do

We develop new atomic-to-nanoscale characterization techniques based on scanning transmission electron microscopy (STEM) to investigate the structural origins of a wide range of important properties of materials. We combine the novel STEM techniques, including fluctuation microscopy, electron nano diffraction, and 4D-STEM, with advanced computational simulations to determine the important structure-property relationships beyond the limits of any conventional characterization or simulation methods. Our current research focus includes the investigation of point and extended defects that dictate the electronic and doping properties of wide band gap semiconductors, the structure, chemistry, and morphology of low-dimensional materials and interfaces, and the nanoscale structural heterogeneity that connects to mechanical and electrical properties of disorders materials, including metallic glasses and amorphous thin films.

 

News

  • Jinwoo Hwang receives the Lumley Research Award from OSU College of Engineering (2019). Read more

  • Jinwoo Hwang receives the NSF CAREER Award for his proposal "Novel Debye Waller Thermometry of Oxide Interfaces for Reducing Thermal Interface Resistance" (2019). Read more

  • Electron Microscopy Pixel Array Detector (EMPAD) has been installed in our STEM ! (2019) Read more

  • New collaborative project with Air Force Research Laboratory will focus on the structure and chemistry of interfaces within soft materials (2018). Read more

  • Our Proto-IRG funding from the Center for Emergent Materials at OSU, "Structure, Defects, and Emergent Properties at Magnetic Oxide Interfaces" has been renewed (2018).

  • A new PhD student, Hsien-Lien Huang, has joined our group (2018).

  • A new PhD student, Mehrdad Abbasi, has joined our group (2018).

  • New MURI project (2018): "Gallium Oxide Materials Science and Engineering", led by James Speck at UCSB, has been selected for funding from AFOSR MURI. Press release

  • A new PhD student, Menglin Zhu, has joined our group (2018).

  • New project (2017) : "Structure, Defects, and Emergent Properties at Magnetic Oxide Interfaces", a Proto-IRG grant supported by the Institution of Materials Research and Center for Emergent Materials at OSU. Read more

  • New project (2017) : Our team project, "Novel Methods for the Design and Fabrication of Complex Disordered Solids", has been awarded with funding from the National Science Foundation (NSF-DMREF). Read more

  • New project (2017) : "Ultra Wide Band Gap III-Nitride Semiconductor Materials and Devices", in collaboration with Prof. Siddharth Rajan at OSU, and funded by the Air Force Office of Scientific Research (AFOSR). Read more

  • New project (2017) : “Correlating Structural Heterogeneity to Deformation in Metallic Glasses”, led by Jinwoo Hwang, has been awarded with funding from the National Science Foundation (NSF). Read more

  • Jared and Jinwoo have contributed to the development of remote epitaxy of semiconductor films using graphene, which is published in Nature and featured on the cover of Nature Vol. 544 (2017). Press release

 

CEMAS at OSU

Visit our microscopy center https://cemas.osu.edu/

Recent Publications

  • M.R. Karim, Z. Feng, J. M. Johnson, M. Zhu, J. Hwang, and H. Zhao, "Low pressure chemical vapor deposition of In2O3 films on off-axis c-sapphire substrates”, Crystal Growth & Design (2019).

  • N. Mehrabi, A. Masud, M. Afolabi,  J. Hwang,  G. A. Calderon Ortiz  and  N. Aich,  "Magnetic Graphene Oxide-Nano Zero Valent Iron (GO-nZVI) Nanohybrids Synthesized using Biocompatible Cross-linkers for Contaminant Removal", RSC Advances 9, 963 (2019).

  • S. Im, Z. Chen, J. M. Johnson, P. Zhao, G. H. Yoo, E. S. Park, Y. Wang, D. A. Muller, and J. Hwang, "Direct Determination of Structural Heterogeneity in Metallic Glasses Using Four-Dimensional Scanning Transmission Electron Microscopy" Ultramicroscopy 195, 189 (2018).

  • Y. Zhang, A. Neal, Z. Xia, C. Joishi, J. M. Johnson, Y. Zheng, S. Bajaj, M. Brenner, D. Dorsey, K. Chabak, G. Jessen, J. Hwang, S. Mou, J. P. Heremans, and S. Rajan, “emonstration of high mobility and quantum transport in modulation-doped β-(AlxGa1-x)2O3/Ga2O3 heterostructures”, Appl. Phys. Lett. 112, 173502 (2018).

  • M. Souri, J. Terzic, J. M. Johnson, J. G. Connell, J. H. Gruenewald, J. Thompson, J. W. Brill, J. Hwang, G. Cao, and A. Seo, “Electronic and optical properties of La-doped Sr3Ir2O7 epitaxial thin-films”, Physical Review Materials 2, 024803 (2018).

  • Subrina Rafique, Md Rezaul Karim, Jared Johnson, Jinwoo Hwang and Hongping Zhao, “LPCVD homoepitaxy of Si doped β-Ga2O3 thin films on (010) and (001) substrates”, Appl. Phys. Lett. 112, 052104 (2018).

  • Yuewei Zhang, Zane Jamal-Eddine, Fatih Akyol, Sanyam Bajaj, Jared M. Johnson, Gabriel Calderon, Andrew A. Allerman, Michael W. Moseley, Andrew M. Armstrong, Jinwoo Hwang, and Siddharth Rajan, “Tunnel-injected sub 290 nm ultra-violet light emitting diodes with 2.8 % external quantum efficiency”, Appl. Phys. Lett. 112, 071107 (2018).

  • Pengyang Zhao, Ju Li, Jinwoo Hwang, and Yunzhi Wang, "Influence of nanoscale structural heterogeneity on shear banding in metallic glasses", Acta Materialia 134, 104 (2017). 

  • Y. Kim, S. S. Cruz, Y. Song, B. Alawode, J. M. Johnson, C. Heidelberger, W. Kong, S. Choi, Y. S. Lee, C. Choi, E. A. Fitzgerald, A. Kolpak, J. Kong, J. Hwang, and J. Kim, "Remote epitaxy through graphene for two-dimensional material based layer transfer", Nature 544, 340 (2017). 

  • Jared Johnson, Soohyun Im, Wolfgang Windl, and Jinwoo Hwang, "Three-dimensional imaging of individual point defects using selective detection angles in annular dark field scanning transmission electron microscopy", Ultramicroscopy 172, 17 (2017). 

  • J. H. Gruenewald, J. H. Kim, H. S. Kim, J. M. Johnson, Jinwoo Hwang, M. Souri, J. Terzic, S. H. Chang, A. Said, J. W. Brill, G. Cao, H. Y. Kee, and S. S. A. Seo, “Engineering 1D Quantum Stripes from Superlattices of 2D Layered Materials”, Advanced Materials 29, 1603798 (2017).  

  • Sriram Krishnamoorthy, Zhanbo Xia, Yuewei Zhang, Chandan Joishi, Joe McGlone, Jared Johnson, Mark Brenner, Aaron R. Arehart, Jinwoo Hwang, and Siddharth Rajan, “Modulation-doped β-(AlxGa1-x)2O3/ Ga2O3 Field-Effect Transistor” Appl. Phys. Lett. 111, 023502 (2017). 

  • See the entire list of publication here