Tailor-made additives, which are molecules that share the same molecular structure as a parent molecule with only slight structural variations, have previously been demonstrated as a useful means to control crystallization dynamics in solution. For example, tailor-made additives can be added to solutions of a crystallizing parent molecule to alter the crystal growth rate, size, and shape. We apply this strategy as a means to predictably control morphology in molecular bulk-heterojunction (BHJ) photovoltaic cells. Through the use of an asymmetric oligomer substituted with a bulky triisobutylsilyl end group, the morphology of BHJ blends can be controlled resulting in a near doubling (from 1.3 to 2.2%) in power conversion efficiency. The use of tailor-made additives provides promising opportunities for controlling crystallization dynamics, and thereby film morphologies, for many organic electronic devices such as photovoltaics and field-effect transistors. © 2012 American Chemical Society.
|Original language||English (US)|
|Number of pages||9|
|Journal||ACS Applied Materials & Interfaces|
|State||Published - Dec 24 2012|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: We gratefully acknowledge the AFOSR (FA9550-09-1-0320) for financial support. K.R.G. and R.S. acknowledge the University Alumni Awards Program for a fellowship. We acknowledge the Major Analytical Instrumentation Center, Department of Materials Science and Engineering, University of Florida, for TEM and FIB facility use. We thank Prof. Baskar Ganapathysubramanian (Iowa State University) and Prof. Aram Amassian (King Abdullah University of Science and Technology) for suggestions on TEM image processing.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.