Effects of additives on the morphology of solution phase aggregates formed by active layer components of high-efficiency organic solar cells

Sylvia J Lou; Jodi M Szarko; Tao Xu; Luping Yu; Tobin J Marks; Lin X Chen

doi:10.1021/ja2085564

Effects of additives on the morphology of solution phase aggregates formed by active layer components of high-efficiency organic solar cells

J Am Chem Soc. 2011 Dec 28;133(51):20661-3. doi: 10.1021/ja2085564. Epub 2011 Dec 5.

Authors

Sylvia J Lou¹, Jodi M Szarko, Tao Xu, Luping Yu, Tobin J Marks, Lin X Chen

Affiliation

¹ Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA.

PMID: 22126463
DOI: 10.1021/ja2085564

Abstract

Processing additives are used in organic photovoltaic systems to optimize the active layer film morphology. However, the actual mechanism is not well understood. Using X-ray scattering techniques, we analyze the effects of an additive diiodooctane (DIO) on the aggregation of a high-efficiency donor polymer PTB7 and an acceptor molecule PC(71)BM under solar cell processing conditions. We conclude that DIO selectively dissolves PC(71)BM aggregates, allowing their intercalation into PTB7 domains, thereby optimizing both the domain size and the PTB7-PC(71)BM interface.