Abstract
Scanning Kelvin probe microscopy was used to measure band-bending at the model donor/acceptor heterojunction poly(3-hexylthiophene) (P3HT)/fullerene (C60). Specifically, we measured the variation in the surface potential of C60 films with increasing thicknesses grown on P3HT to produce a surface potential profile normal to the substrate both in the dark and under illumination. The results confirm a space-charge carrier region with a thickness of 10 nm, consistent with previous observations. We discuss the possibility that the domain size in bulk heterojunction organic solar cells, which is comparable to the space-charge layer thickness, is actually partly responsible for less than expected electron/hole recombination rates.
Original language | English (US) |
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Pages (from-to) | 5772-5776 |
Number of pages | 5 |
Journal | ACS Applied Materials and Interfaces |
Volume | 8 |
Issue number | 9 |
DOIs | |
State | Published - Mar 9 2016 |
Bibliographical note
Funding Information:The authors acknowledge financial support from NSF Grant DMR-0706011.
Publisher Copyright:
© 2016 American Chemical Society.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
Keywords
- band bending
- charge generation layer
- fullerene
- polymer
- scanning kelvin probe