|Title||Influence of Processing Additives on Charge-Transfer Time Scales and Sound Velocity in Organic Bulk Heterojunction Films|
|Publication Type||Journal Article|
|Year of Publication||2012|
|Authors||Kaake LG, Welch GC, Moses D, Bazan GC, Heeger AJ|
|Journal||Journal of Physical Chemistry Letters|
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.