  Singlet fission, an exciton multiplication process in organic semiconductors
which converts one singlet exciton into two triplet excitons is a promising way
to reduce thermalization losses in conventional solar cells. One way to harvest
triplet excitons is to transfer their energy into quantum dots, which then emit
photons into an underlying solar cell. We simulate the performance potential of
such a singlet fission photon multiplier combined with a silicon base cell and
compare it to a silicon-based tandem solar cell. We calculate the influence of
various loss-mechanisms on the performance potential under real-world operation
conditions using a variety of silicon base cells with different efficiencies.
We find that the photon multiplier is more stable against changes in the solar
spectrum than two-terminal tandem solar cells. We furthermore find that, as the
efficiency of the silicon solar cell increases, the efficiency of the photon
multiplier increases at a higher rate than the tandem solar cell. For current
record silicon solar cells, the photon multiplier has the potential to increase
the efficiency by up to 4.2% absolute.
