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 base 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.

E.C. Garnett (Erik)
ACS Energy Lett.
Hybrid Solar Cells

Futscher, M.H, Rao, A, & Ehrler, B. (2018). The Potential of Singlet Fission Photon Multipliers as an Alternative to Silicon-based Tandem Solar Cells. ACS Energy Lett., 3(10), 2587–2592. doi:10.1021/acsenergylett.8b01322