polymer crystallization on curved surfaces
DESCRIPTION
Polymer Crystallization on Curved Surfaces. Steve Kuei. Overview. Introduction Organic electronics Motivation Experimental Previous work Buckling Structures Atomic Force Microscopy Conclusions Future work. Organic Electronics. Solar Cells. Al. ITO. Motivation. - PowerPoint PPT PresentationTRANSCRIPT
Polymer Crystallization on Curved Surfaces
Steve Kuei
Overview
• Introduction– Organic electronics– Motivation
• Experimental– Previous work– Buckling Structures– Atomic Force Microscopy
• Conclusions• Future work
AlAl
Organic Electronics
• Solar Cells
ITOITO
Motivation
• Polymer crystallization
Previous work
A. Hexemer, V. Vitelli, E.J. Kramer, G. H. Fredrickson
Previous work
A. Hexemer, V. Vitelli, E.J. Kramer, G. H. Fredrickson
Curvature
• Principal curvatures,
• Mean curvature – average of principal curvatures
• Gaussian Curvature – product of principal curvatures
Buckling Structures
Atomic Force Microscopy
Wikipedia, by Askewmind Images by Vijay Narayan
AFM and buckling structures
AFM and buckling structures
P3EHT
Polymer synthesized by Segalman Group, Berkeley
M.W. 7k g/mol
P3EHT – spin coated
P3EHT – annealed for 12 hours
P3EHT – annealed for 12 hours
P3EHT – annealed for 2 days
Future work
• Film thickness– Currently too thick, pooling in trenches– Orientation underneath surface layer is unknown
• Buckling structures– Need to optimize amplitude and period of buckling
structures so that polymer stays on the peaks– Need to control buckling structures to have regularly
occurring gaussian curvature
• Conclusions– Gaussian curvature appears to dominate, especially
after annealing for longer periods of time, aligning polymer fibers along the troughs.
Acknowledgements
• Princeton Environmental Institute Energy Grand Challenge
• MIRTHE/PCCM REU program
• Professor Loo, Professor Yao, Dr. Hexemer• Eleni Pavlopoulou, Jongbok Kim, Stephanie Lee,
Pilnam Kim, Rich Fiorillo, Atray Dixit, Vijay Narayan