Theoretical modeling on luminescent down-shifting process: A Discussion on luminescent molecule design

A model was developed to describe the luminescent down-shifting (LDS) process in photovoltaic application. The model links the J
_sc
enhancement (J
_LDS
%) of the solar cell to the photophysical properties including absorption (λ
_abs
) and emission (λ
_em
) wavelengths, Stokes shift (Δλ) and spectral cutting point (λ
_SCP
), as well as fluorescence quantum yield (Φ
_f
), of the luminescent molecules. It suggests that Φ
_f
is a more crucial parameter than λ
_abs
and λ
_em
. It also suggests that λ
_SCP
is a better parameter than Δλ on describing J
_LDS
%. The model is tested with luminescent molecules and the results are consistent with the experimental results.