  Photocurrent matching in conventional monolithic tandem solar cells is
achieved by choosing semiconductors with complementary absorption spectra and
by carefully adjusting the optical properties of the complete top and bottom
stacks. However, for thin film photovoltaic technologies at the module level,
another design variable significantly alleviates the task of photocurrent
matching, namely the cell width, whose modification can be readily realized by
the adjustment of the module layout. Herein we demonstrate this concept at the
experimental level for the first time for a 2T-mechanically stacked perovskite
(FAPbBr3)/organic (PM6:Y6:PCBM) tandem mini-module, an unprecedented approach
for these emergent photovoltaic technologies fabricated in an independent
manner. An excellent Isc matching is achieved by tuning the cell widths of the
perovskite and organic modules to 7.22 mm (PCEPVKT-mod= 6.69%) and 3.19 mm
(PCEOPV-mod= 12.46%), respectively, leading to a champion efficiency of 14.94%
for the tandem module interconnected in series with an aperture area of 20.25
cm2. Rather than demonstrating high efficiencies at the level of small lab
cells, our successful experimental proof-of-concept at the module level proves
to be particularly useful to couple devices with non-complementary
semiconductors, either in series or in parallel electrical connection, hence
overcoming the limitations imposed by the monolithic structure.
