We have successfully controlled the polymer orientation by carefully tuning the length and shape of the solubilizing alkyl side chains. With the ideal polymer orientation, charge carriers generated upon sun light absorption can effectively travel through the polymer films, which resulted in the significant improvement of the power conversion efficiency in polymer-based solar cells. This methodology would pave the way towards the practical use of polymer-based solar cells.
Research Area: “Photoenergy conversion systems and materials for the next generation solar cells”
Research Theme: “Novel semiconducting polymers toward high efficiency organic thin film solar cells”
Itaru Osaka, Masahiko Saito, Tomoyuki Koganezawa, Kazuo Takimiya.
“Thiophene-Thiazolothiazole Copolymers: Significant Impact of Side Chain Composition on Backbone Orientation and Solar Cell Performances”
Advanced Materials, Published online 8 October 2013
Itaru Osaka, Ph.D.
Senior Research Scientist, Center for Emergent Matter Science, RIKEN
Koji Matsuo, Masashi Furukawa, Natsuko Kawazoe
Green Innovation Group, Department of Innovation Research,
Japan Science and Technology Agency