  Implementation of resonant colloidal nanoparticles for improving performance
of organometal halide perovskites solar cells is highly prospective approach,
because it is compatible with the solution processing techniques used for any
organic materials. Previously, resonant metallic nanoparticles have been
incorporated into perovskite solar cells for better light absorption and charge
separation. However, high inherent optical losses and high reactivity of noble
metals with halides in perovskites are main limiting factors for this approach.
In turn, low-loss and chemically inert resonant silicon nanoparticles allow for
light trapping and enhancement at nanoscale, being suitable for thin film
photovoltaics. Here photocurrent and fill-factor enhancements in
meso-superstructured organometal halide perovskite solar cells, incorporating
resonant silicon nanoparticles between mesoporous TiO2 transport and active
layers, are demonstrated. This results in a boost of the device efficiency up
to 18.8\% and fill factor up to 79\%, being a record among the previously
reported values on nanoparticles incorporation into CH3NH3PbI3 (MAPbI3)
perovskites based solar cells. Theoretical modeling and optical
characterization reveal the significant role of Si nanoparticles for increased
light absorption in the active layer rather than for better charge separation.
The proposed strategy is universal and can be applied in perovskite solar cells
with various compositions, as well as in other optoelectronic devices.
