Background: The phase-separated structure of a three-component system in a bulkheterojunction
solar cell could be controlled by using a p-type semiconducting polymer/titanium
alkoxide/fullerene derivative as the carrier management layer.
Methods: Addition of the adequate amount of fullerene derivative as the phase separation assistant
material in the photoactive layer resulted in a higher short-circuit current density (Jsc) as compared to
that in the conventional two-component bulk-heterojunction solar cell. The three-component carrier
management layer containing the fullerene derivative as the phase separation assistant material contributed
to the formation of many p/n interfaces and a continuous phase-separated structure for the
charge separation and charge transfer, as revealed by scanning electron microscopy observations.
Results: Moreover, we report about short-term air stability of the solar cells.
Conclusion: A stability test performed after 30 days indicated that the performance of the threecomponent
system was equivalent to that of the conventional two-component system, which used a
fullerene derivative as the electron acceptor, although the number of interfaces between different species
was larger in the former.