Sushobhan Avasthi, Bahman Hekmatshoar, Global Photonic Energy Corporation (GPEC) Graduate Award Co-winners; David G. Kwabi, Undergraduate GPEC winner
From left, Prof. Jim Sturm, PRISM Director, GPEC Co-winners Sushobhan Avasthi and Bahman Hekmatshoar, and PRISM Associate Academic Director Prof. Craig Arnold. (Photo by Sheila Gunning)
Sushobhan Avasthi, a graduate student in Electrical Engineering, came to Princeton from the Indian Institute of Technology in Kanpur. He is a member of the group of James C. Sturm, William and Edna Macaleer Professor of Engineering and Applied Science, and Director of the Princeton Institute for the Science and Technology of Materials (PRISM). Sushobhan has done pioneering work on the fundamental properties of the interfaces between organic/inorganic semiconductors, and their application to photovoltaics. Prof. Sturm writes “Sushobhan showed for the first time how monolayers of certain semiconducting organic molecules could “passivate” the otherwise detrimental effects of dangling bonds at the silicon surface. This advance enables one to finally be able to engineer the silicon/organic hybrid structures for photovoltaics, and thus take advantage of the best properties of both organic and inorganic materials.” In interdisciplinary fashion, he has interacted extensively with the groups of Jeff Schwartz in Chemistry, Antoine Kahn in Electrical Engineering, and Lynn Loo in Chemical Engineering to combine surface chemistry and surface science with semiconductor engineering. Last year he presented one application of his work to increase solar cell efficiency at the IEEE Photovoltaic Specialists Conference, and at the December 2009 Symposium of the Materials Research Society. Sushobhan's work, "Stability of Electrical Properties of Silicon (100) Surfaces Passivated with 9, 10-Phenanthrenequinone,” was recognized with a Best Student Poster Award.
David G. Kwabi attends the School of Engineering and Applied Science (SEAS) Award ceremony on Class Day, May 31, 2010. (Photo by Frank Wojciechowski)
Undergraduate GPEC winner David G. Kwabi of the Mechanical and Aerospace Engineeing (MAE) Department completed an excellent senior thesis on the failure of mechanisms in flexible and organic electronic structures entitled "Adhesion and Failure in Stretchable Organic Electronic Structures" states Prof. Wole Soboyejo, David's advisor.
David was also co-winner of the Morgan W. McKinzie '93 Senior Thesis Prize for the best thesis in MAE. He graduates with honors, was inducted into the Sigma Xi Scientific Research Society and completed a certificate program in Materials Science and Engineering. David came to Princeton from Sos-Hermann Gmeiner International College (high-school) in Ghana. He heads to MIT for graduate school in the fall. Congratulations, David!
Abstract: This work presents the results of an experimental study on adhesion and stretching of organic electronic structures that are relevant to organic solar cells. The adhesion between bi-material pairs that are relevant to these systems is measured using atomic force microscopy techniques. The effects of stretching are then examined by deforming poly-dimethly-siloxane (PDMS) substrates with model organic solar cells deposited on plasma-treated surfaces. Residual stress is characterized using wrinkling patterns observed. Degradation mechanisms of Au films on PDMS at different thicknesses are examined to shed light on similar behavior in the stretched devices. The implications of these results are then examined for the future development of stretchable and flexible organic solar cells and organic light-emitting devices.