Postdoctoral Researcher, University of Pennsylvania
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Presented: September 17 and 18, 2020
“Manufacturing of Advanced Materials for the 21st Century”
In the past century, materials science and engineering brought about the revolutionization of airplanes (1903-present) and the invention of vacuum tubes (1904) and transistors (1947). Today, we face a wide range of engineering challenges from the end of Moore’s Law scaling to environmental pollution. Materials science and engineering has an important role in the manufacture of advanced materials for these applications. This effort will require materials synthesis, structural characterization, functional property measurement, and process mechanism understanding. This presentation will describe a series of experiments that involve each of these elements. The first part will demonstrate epitaxy of core-shell Ge/GeSn nanowires for photonics applications and give some insights on the growth mechanism. The second part will focus on structural characterization of these nanowires—strain and Sn composition in GeSn play an important role in its optoelectronic properties. The third part will describe an application of electrochemical impedance spectroscopy to measurement of electrical defects at high-aspect-ratio semiconductor-oxide interfaces. The last part will apply in-situ gas cell TEM to the oxidation of Pt/Pd/Al2O3 automotive emissions catalyst to demonstrate that process monitoring can give important insights on underlying structural evolution mechanisms. Combining in-situ TEM with growth and functional property measurements will vertically integrate the different aspects of manufacturing advanced materials and can be an incredibly powerful method for understanding fabrication processes.
Andrew Meng, Ph.D., Postdoctoral Researcher, University of Pennsylvania
Andrew Meng has been a postdoctoral scholar in the Department of Materials Science and Engineering at the University of Pennsylvania since 2019. Andrew earned a Ph.D. and M.S. in materials science and engineering at Stanford University in 2019. Andrew received a M.Phil. in chemistry in 2014 from the University of Cambridge as a Churchill Scholar. He graduated with a B.S. in physics and chemistry from the California Institute of Technology in 2013. He was awarded the Ross N. Tucker Memorial Award (2019), a Materials Research Society Graduate Student Silver Award (Spring 2019), an NSF Graduate Research Fellowship (2013-2018), and a Goldwater Scholarship (2012).