There are two critical
strategies to achieve the high photoelectric
conversion efficiency of polymer photovoltaic cells: broadening the
light absorption spectra of the active layer and efficiently splitting
photogenerated excitons with a low probability of recombination. Herein,
we demonstrate the improved light trapping and reduced photogenerated
exciton recombination probability of the inverted heterojunction solar
cells by incorporating C60 fullerene modification. This
approach ameliorates traditional multiblend/layer systems, and allows
multiple acceptor materials to synergistically work. After the fullerene
modification layer was incorporated, the optimal device presents a
25.5% improvement of power conversion efficiency (PCE) up to 9.458%
with an open circuit voltage (V
oc) of
0.8 V, a short-circuit current (J
sc) of
18.575 mA/cm2, and a fill factor (FF) of 63.4%. This study
provides a novel inspiration for the structure development of high-efficiency
photovoltaic devices.