The figure shows the fill factors as a function of the open-circuit voltage of different solar cell types at 1 sun and T = 300 K. The lines is the theoretical expression for Shockley diode at the indicated value of the diode quality factor, m. For a DSC m is the reciprocal of the effective recombination order. The data points are for three dye-sensitized solar cells (DSC) of very high quality, for a normal DSC with standard N719 (in this case the series resistance ffect is subtracted), and for a BHJ. For comparison, the data points of record solar cells of different technologies are given.
The fill factors of DSC were discussed in a recent paper.
The idea of this paper was to show that recombination order in DSC different than 1, in general, and the implications of this important fact. There is a connection between the fill factor, the effective recombination order, and the variation of the diffusion length with the voltage.
Reference of the solar cells in the graphic:
-Dye Z991 (12.2%, Grätzel, M. 2009, presented at MRS Fall Meeting in Boston)
-Dye C106 (11.4%, Cao, Y.; Bai, Y.; Yu, Q.; Cheng, Y.; Liu, S.; Shui, D.; Gao, F.; Wang, P. “Dye-Sensitized Solar Cells with a High Absorptivity Ruthenium Sensitizer Featuring a 2-(Hexylthio)thiophene Conjugated Bipyridine”. J. Phys. Chem. C 2009, 113, 6290–6297).
-Dye D131 (5.1%, Ogura, R. Y.; Nakane, S.; Morooka, M.; Orihashi, M.; Suzuki, Y.; Noda, K. “High-performance dye-sensitized solar cell with a multiple dye system “. Appl. Phys. Lett. 2009, 94, 073308).