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)|
|Number of pages||5|
|Journal||ACS Applied Materials and Interfaces|
|State||Published - Mar 9 2016|
Bibliographical noteFunding Information:
The authors acknowledge financial support from NSF Grant DMR-0706011.
© 2016 American Chemical Society.
Copyright 2017 Elsevier B.V., All rights reserved.
- band bending
- charge generation layer
- scanning kelvin probe