1 research outputs found
Measuring the Thickness and Potential Profiles of the Space-Charge Layer at Organic/Organic Interfaces under Illumination and in the Dark by Scanning Kelvin Probe Microscopy
Scanning
Kelvin probe microscopy was used to measure band-bending
at the model donor/acceptor heterojunction poly(3-hexylthiophene)
(P3HT)/fullerene (C<sub>60</sub>). Specifically, we measured the variation
in the surface potential of C<sub>60</sub> 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