  SCAPS-1D software ignores optical losses and recombination junction (RJ)
layer in studying tandem solar cells (TSCs). This paper presents an
optoelectronic study of a perovskite/Silicon TSC, comparing the effects of
using two different methods of calculating filtered spectra on the photovoltaic
performance parameters of tandem device. It is shown that integrating transfer
matrix (TM) method into SCAPS-1D addresses per-layer optical losses and
provides a platform for optimizing the RJ layer in TSCs. Using Beer-Lambert
(BL) method for calculating the filtered spectra transmitted from the
perovskite top sub-cell is revealed to overestimate the cell efficiency by ~4%,
due to its inability to fully address optical losses. Also, the BL method fails
to tackle any issues regarding optical improvement through ITO ad-layer on the
RJ. Using TM formalism, the efficiency of the proposed perovskite/Silicon TSC
is shown to be increased from 19.81% to 23.10%, by introducing the ITO ad-layer
on the RJ. It is the first time that the effect of filtered spectrum
calculation method is clearly investigated in simulating TSCs with SCAPS-1D.
The results pave the way to introduce the optical loss effects in SCAPS-1D and
demonstrate that the BL method that has been used before needs to be revised.
