Share Email Print
cover

Proceedings Paper

Non-thermal free carrier formation in organic photovoltaic polymer blends
Author(s): Ryan D. Pensack; Larry W. Barbour; Maureen Hegadorn; John B. Asbury
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

Ultrafast visible pump - infrared probe spectroscopy is used to examine the dynamics of free carrier formation following photoinduced electron transfer in an organic photovoltaic polymer blend. The carbonyl (C=O) stretch of the functionalized fullerene, PCBM, is probed as a local vibrational reporter of the dynamics in a blend with a conjugated polymer, CN-MEH-PPV. It has been determined that PCBM molecules at the interfaces of PCBM and polymer phases possess higher frequency carbonyl vibrational modes while molecules in the centers of PCBM domains have lower frequency modes. The shift in frequency of the carbonyl stretching mode is used to directly resolve the dynamics of free carrier formation that occur on the few picosecond timescale. The fast dynamics suggest that the presence of an interfacial dipole causes the charge carriers to experience a smaller Coulombic potential than that which would be predicted from the dielectric properties of the materials. The free carrier formation dynamics are temperature independent indicating that excess vibrational energy remaining for a short period of time after the

Paper Details

Date Published: 21 August 2009
PDF: 10 pages
Proc. SPIE 7396, Physical Chemistry of Interfaces and Nanomaterials VIII, 73960R (21 August 2009); doi: 10.1117/12.826373
Show Author Affiliations
Ryan D. Pensack, The Pennsylvania State Univ. (United States)
Larry W. Barbour, The Pennsylvania State Univ. (United States)
Maureen Hegadorn, The Pennsylvania State Univ. (United States)
John B. Asbury, The Pennsylvania State Univ. (United States)


Published in SPIE Proceedings Vol. 7396:
Physical Chemistry of Interfaces and Nanomaterials VIII
Oliver L. A. Monti; Oleg V. Prezhdo, Editor(s)

© SPIE. Terms of Use
Back to Top