Influence of Processing Additives on Charge-Transfer Time Scales and Sound Velocity in Organic Bulk Heterojunction Films

TitleInfluence of Processing Additives on Charge-Transfer Time Scales and Sound Velocity in Organic Bulk Heterojunction Films
Publication TypeJournal Article
Year of Publication2012
AuthorsKaake LG, Welch GC, Moses D, Bazan GC, Heeger AJ
JournalJournal of Physical Chemistry Letters
Volume3
Pagination1253-1257
ISSN1948-7185
Abstract

The role of processing additives in organic bulk heterojunction thin films was investigated by means of transient absorption spectroscopy. The rate of ultrafast charge transfer was found to increase when a small amount of diiodooctane was used during film formation. In addition, coherent acoustic phonons were observed, and their velocity was determined. A strong correlation between the sound velocity and the charge-transfer time scale was observed, both of which could be explained by a subtle increase in thin film density.

DOI10.1021/jz300365b