Abstract:
Organic and perovskite semiconductor materials are considered an interesting combination
thanks to their similar processing technologies and band gap tunability. Here, we present the design
and analysis of perovskite/organic tandem solar cells (TSCs) by using a full optoelectronic simulator
(SETFOS). A wide band gap lead-free ASnI2Br perovskite top subcell is utilized in conjunction with a
narrow band gap DPPEZnP-TBO:PC61BM heterojunction organic bottom subcell to form the tandem
configuration. The top and bottom cells were designed according to previous experimental work
keeping the same materials and physical parameters. The calibration of the two cells regarding
simulation and experimental data shows very good agreement, implying the validation of the
simulation process. Accordingly, the two cells are combined to develop a 2T tandem cell. Further,
upon optimizing the thickness of the front and rear subcells, a current matching condition is satisfied
for which the proposed perovskite/organic TSC achieves an efficiency of 13.32%, Jsc of 13.74 mA/cm2
,
and Voc of 1.486 V. On the other hand, when optimizing the tandem by utilizing full optoelectronic
simulation, the tandem shows a higher efficiency of about 14%, although it achieves a decreased Jsc
of 12.27 mA/cm2
. The study shows that the efficiency can be further improved when concurrently
optimizing the various tandem layers by global optimization routines. Furthermore, the impact
of defects is demonstrated to highlight other possible routes to improve efficiency. The current
simulation study can provide a physical understanding and potential directions for further efficiency
improvement for lead-free perovskite/organic TSC.
