The Electronic Materials and Devices Laboratory (EMDL) is comprised of students and senior researchers with diverse backgrounds across the disciplines of Electrical Engineering, Physics, Materials Science, Chemistry, and Chemical Engineering. Such breadth allows vertical integration of research in electronic materials, nanostructures, optoelectronics, photovoltaics, electronics, device fabrication and integrated systems. The interdisciplinary philosophy of research within EMDL grants a unique perspective and results in extensive collaboration with other groups, at OSU and beyond.


The Electronic Materials and Devices Laboratory (EMDL) at Ohio State is located in the Department of Electrical Engineering and is directed by Professor Steven A. Ringel. For more information about activities and opportunities, please contact the EMDL Executive Assistant, Ms. Jennifer Donovan, at

Recent Publications


E. Farzana, A. Mauze, J. B. Varley, T. Blue, J. S. Speck, A. R. Arehart, and S. A. Ringel, “Influence of Neutron Irradiation on Deep Levels in Ge-doped (010) β-Ga2O3 layers grown by plasma-assisted molecular beam epitaxy,” APL Materials 7, 121102 (2019).
Yuewei Zhang, Steven A. Ringel and Siddharth Rajan, “Evaluation of Low-Temperature Saturation Velocity in b-(AlxGa1-x)2O3/Ga2O3 Modulation-doped Field Effect Transistors,” accepted and to appear IEEE Trans. Electron Dev. (2019).
Wenyuan Sun, Steven A. Ringel and Aaron R. Arehart, “Investigation of Trap-induced Threshold Voltage Instability in GaN-on-Si MISHMETs,” accepted and to appear, IEEE Trans. Electron Dev. (2019).
D. A. Gleason, K. Galiano, J. L. Brown, A. M. Hilton, S. A. Ringel, A. R. Arehart, E. R. Heller, D. L. Dorsey, and J. P. Pelz, Local Trap Spectroscopy on Cross-Sectioned AlGaN/GaN Devices with In Situ Biasing, Applied Physics Letters, 114, 053510 (2019).
Esmat Farzana, Max F. Chaiken, Thomas E. Blue, Aaron R. Arehart and Steven A. Ringel, “Impact of deep level defects induced by high energy neutron radiation in b-Ga2O3,” APL Materials 7, 022502 (2019). 


P. Altermatt, Zhen Xiong, QiuXiang He, WeiWei Deng, Yang Yang, Yifeng Chen, ZhiQiang Feng, Pierre J. Verlinden, Anyao Liu, Daniel H. Macdonald, Tabea Luka, Dominik Lausch, Marko Turek, Christian Hagendorf, Hannes Wagner-Mohnsen,  Jonas Schön, Wolfram Kwapil , Felix Frühauf, Otwin Breitenstein, Erin E.Looney, Tonio Buonassisi, David B.Needleman, Christine M. Jackson, Aaron R. Arehart, Steven A. Ringel, Keith R. McIntosh, Malcolm D. Abbott, Ben A. Sudbury, Annika Zuschlag, Clemens Winter, Daniel Skorka, Giso Hahn, Daniel Chung, Bernhard Mitchell, Peter Geelan-Small and Thorsten Trupkek, “High-performance p-type multicrystalline silicon (mc-Si): Its characterization and projected performance in PERC solar cells,” Solar Energy 175, pp. 68-74 (2018).

Daniel J. Chmielewski, Daniel. L. Lepkowski, Jacob T. Boyer, Tyler J. Grassman and Steven A. Ringel, “Comparative Study of ! 2.05 eV Lattice-matched and Metamorphic (Al)GaInP Solar Cells Grown by MOCVD,” IEEE Journal of Photovoltaics 8 (6), 1601-1607 (2018).

E. Farzana, H. M. Foronda, C. M. Jackson, T. Razzak, Z. Zhang, J. S. Speck, A. R. Arehart, and S. A. Ringel, “Characterization of traps in InAlN by optically and thermally stimulated deep level defect spectroscopies,” J. Appl. Phys. 124 (14), 145703 (2018).  

Joe. F. McGlone, Zhanbo Xia, Yuewei Zhang, Chandan Joishi, Saurabh Lodha, Siddharth Rajan, Steven A. Ringel, Aaron R. Arehart, “Trapping Effects in Si δ-Doped β-Ga2O3 MESFETs on an Fe-Doped β-Ga2O3 Substrate,” IEEE Electron Device Letters, vol. 39, no. 7, pp. 1042–1045, Jul. 2018. 

Kevin Galiano, J. I. Deitz, S. D. Carnevale, D. A. Gleason, P. K. Paul, Z. Zhang, B. M. McSkimming, J. S. Speck, S. A. Ringel, T. J. Grassman,   A. R. Arehart, and J. P. Pelz, “Spatial correlation of the Ec-0.57 eV trap state with edge dislocations in epitaxial n-type gallium nitride”, Journal of Applied Physics 123, 224504, 2018. ttps://

Esmat Farzana, Elaheh Ahmadi, James S. Speck, Aaron R. Arehart, and Steven A. Ringel, “Deep level defects in Ge-doped (010) β-Ga2O3 layers grown by plasma-assisted molecular beam epitaxy” in Journal of Applied Physics 123 (16), 161410 (2018). (Most cited article on physical properties on semiconductors in Journal of Applied Physics in 2019 that were published in 2018

C. Joishi, Z. Xia, J. McGlone, Y. Zhang, A.R. Arehart, S.A. Ringel, S. Lodha, and S. Rajan, “Effect of Buffer Iron Doping on Delta-doped b-Ga2O3 Metal Semiconductor Field Effect Transistors,” Appl. Phys. Lett 113 (12), 123501 (2018).


Steven Ringel awarded title of Distinguished University Professor

The Ohio State University awarded Steven Ringel, a faculty member in Electrical and Computer Engineering (ECE), the permanent title of Distinguished University Professor in appreciation of his teaching, research and service at the university.

Ohio State Board of Trustees conferred the appointment during its Aug. 31 meeting, bestowing Ringel the university’s highest honor given to faculty members. Read more

Steve Ringel wins 2018 Distinguished Professor Award

Steve Ringel was named a 2018 Distinguished University Professor in recognition of his exceptional record in teaching, research, and scholarly work at The Ohio State University. Ringel joins a small group of only 57 awardees in receiving the honor throughout Ohio State history. Read More

Christine Jackson receives 2018 Distinguished Graduate Student Award from the Women in Engineering Program

At the 2018 Women in Engineering banquet, Christine Jackson was one of six Distuingished Graduate Student Awardees.

Kevin Galiano and Julia Deitz win the 2017 OSU Materials Week Student Poster Award

Congratulations Kevin Galiano and Julia Deitz! Both won the 2017 OSU Materials Week Student Poster Award. Read More

Esmat’s paper Highlighted in APL

Esmat’s paper, "Influence of metal choice on (010) β-Ga2O3 Schottky diode properties" was highlighted on Applied Physics Letters homepage as an Editor’s Pick in the week of May 21, 2017. The paper represents an in-depth analysis of metal Schottky contact characteristics on β-Ga2O3, transport mechanisms operative in the contacts and, correlation of work function and barrier height with different metal choices. The insights derived will play an important role in gate metal engineering and its functionality for future high power application devices. Read More

Prof. Tyler Grassman Wins SunShot Award to Develop High Efficiency Tandem Solar Cell

Prof. Tyler Grassman (MSE/ECE) was awarded $1,124,999 to develop a tandem solar cell with gallium arsenide phosphide (GaAsP) on silicon (Si) aimed at 30% or higher efficiency. Read More

Daniel Chmielewski Wins Best Student Paper Award at the 43rd IEEE PVSC

Congratulations to Daniel Chmielewski! Daniel won the best student paper award at the 43rd IEEE Photovoltaics Specialist Conference for his presentation "Comparative Study of 2.05 eV AlGaInP and Metamorphic GaInP Materials and Solar Cells Grown by MBE and MOCVD."

Kevin Galiano Wins 2016 OSU Materials Week Student Poster Award

Congratulations Kevin Galiano! Kevin won the 2016 OSU Materials Week Student Poster Award for his project "Spatial Localization of Electron Traps in GaN." Read More

Daniel Chmielewski Wins 2016 Kraus Memorial Poster Competition

Congratulations to Daniel Chmielewski! Daniel won the 2016 Kruas Memorial Poster Competition for his project "III-V/Active-Si Integration for Low-Cost High-Performance Concentrator Photovoltaics". As a reward, he was given the opportunity to present his work at the 2016 OSU ECE Alumni meetup event held at the Engineers' Club of Dayton. Read More

Zeng Zhang awarded MRS 2015 Electronic Materials Conference Best Student Paper Award

Congratulations to Zeng Zhang! Zeng earned the 2015 MRS Electronic Materils Conference Best Student Paper Award for his presentation: "Deep Level States in p-Type GaN Grown by Ammonia-Based Molecular Beam Epitaxy and Metal Organic Chemical Vapor Deposition".

Prof. Steve Ringel Named 2015 OSU Distinguished Scholar

Steve Ringel Receives Distinguished Scholar Award

Professor Steve Ringel was named a 2015 OSU Distinguished Scholar honoring his commitment to research work in wide bandgap semiconductors and photovoltaics and to leadership as Executive Director of the OSU Institute for Materials Research (IMR) and as the Principal Investigator of the Materials and Manufacturing for Sustainability Discovery Theme Initiative. Read more