I am currently a National Science Foundation Graduate Research Fellow and Ph.D. candidate at Northwestern University in the Materials Science and Engineering Department, working under Professor Lincoln J. Lauhon. My research focus is on the nanoscale characterization of III-V nanowire optoelectronic heterostructures, such as InGaAs quantum well lasers. This involves investigating composition in 3D via Atom Probe Tomography and characterizing strain using synchrotron-based coherent x-ray imaging methods. I am particularly interested in nanoprobe x-ray imaging for materials characterization. I expect to graduate in early-mid 2020, and am looking for post-doc positions in the US or Europe.
Northwestern University, Graduate Researcher
September 2015 - Present
My Ph.D. work has involved experimental and computational work, providing me experience in a wide variety of experimental techniques. This has included micromanipulation of nanowires in a focused ion beam system and composition mapping using atom probe tomography. I have worked extensively at Argonne and Brookhaven national labs to characterize strain in nanowires, and help expand x-ray imaging techniques. Both atom probe and coherent x-ray imaging require extensive manipulation of large data sets, which I primarily do in Matlab, but some Python. My work in Bragg ptychographic imaging has given me some experience in iterative optimization algorithms in order to solve the “phase problem” to reconstruct 3D strain maps of nanostructures. I also have experience with finite element modeling of materials heterostructures using COMSOL Multiphysics and simulating kinematic scattering of these modeled heterostructures.
My work at Northwestern has been extremely collaborative. I’ve gotten the opportunity to mentor a younger Ph.D. student on my project. I’ve worked with scientists from both Argonne and Brookhaven National Laboratories extensively. I have collaborated with students and professors from five universities in Germany, Switzerland, and Sweden. These collaborations has been a great opportunity to develop better management, communication, and organizational skills. During my Ph.D. I have also gained effective speaking skills by giving 10+ oral presentations throughout the US and Europe.
Lund University, Visiting Researcher
September 2018 - November 2018
I spent three months researching in Sweden/Germany in Fall 2018, funded through a grant I received from the National Science Foundation as a part of the Graduate Research Opportunities Worldwide (GROW) program. I worked at Lund University in the Synchrotron Radiation Research Division of the Physics Department under Assistant Professor Jesper Wallentin. During this time I worked to compare the benefits of different x-ray ptychography techniques, including performing ptychography experiments on nanowires at Diamond Light Source and the European Synchrotron Radiation Facility.
Cornell UNIVERSITY, Undergraduate Researcher
January 2013 - July 2015
During my undergraduate at Cornell University, while pursuing my B.S. in Materials Science and Engineering, I performed extensive research in the group of Professor Michael O. Thompson. I focused on characterizing the Si-doped InGaAs films annealed using sub-millisecond laser annealing. Dopant activation was characterized using Raman spectroscopy and van der Pauw device measurements. In this time I gained 100+ hours of clean room experience, focusing on creating van der Pauw and thermister devices using contact lithography. During this time, I was awarded a Semiconductor Research Corporation (SRC) / Intel Foundation Scholarship to perform research. I was given the opportunity to present posters at the SRC TECHON conference in 2013 and 2014, winning 2nd and 1st place respectively.
University of California Santa Barbara, Intern - National NanoTechnology Infrastructure Network
May 2014 - August 2014
Through the National Nanotechnology Infrastructure Network, I performed research at UC Santa Barbara in the Department of Materials Science under Professor Susanne Stemmer. My research focused on characterizing the interface of ALD grown low-K dielectrics on InGaAs. This included growing ALD films, and fabricating/testing MOSCAPs to measure interface trapping and current leakage.
Lähnemann, J.*, Hill, M. O.*, Herranz, J., Marquardt, O., Gao, G., Al Hassan, A., ... & Calvo-Almazán, I. (2019). Correlated nanoscale analysis of the emission from wurtzite versus zincblende (In, Ga) As/GaAs nanowire core-shell quantum wells. Nano letters.
Hill, M. O., Calvo-Almazan, I., Allain, M., Holt, M. V., Ulvestad, A., Treu, J., ... & Nazaretski, E. (2018). Measuring Three-Dimensional Strain and Structural Defects in a Single InGaAs Nanowire Using Coherent X-ray Multiangle Bragg Projection Ptychography. Nano Letters, 18(2), 811-819.
Becker, J., Hill, M. O., Sonner, M., Treu, J., Döblinger, M., Hirler, A., ... & Koblmueller, G. (2018). Correlated Chemical and Electrically Active Dopant Analysis in Catalyst-Free Si-Doped InAs Nanowires. ACS Nano. 12 (2), 1603–161.
Stettner, T., Thurn, A., Döblinger, M., Hill, M. O., Bissinger, J., Schmiedeke, P., ... & Kaniber, M. (2018). Tuning Lasing Emission toward Long Wavelengths in GaAs-(In, Al) GaAs Core–Multishell Nanowires. Nano letters, 18(10), 6292-6300.
Northwestern UNIVERSITY, Evanston IL
Ph.D. Materials Science and Engineering
Cornell University, Ithaca, NY
B.S. Materials Science and Engineering
Graduated May 2015
North Kansas City High School, North Kansas City, MO
International Baccalaureate (IB) Recipient
Graduated May 2011