Design and Optimization of Low Lead Content- Based Mixed Sn and Pb Perovskite Solar Cell for 19.46% Efficiency

Organic and inorganic halide perovskite solar cells have gained a lot of attention due to their excellent optical absorption properties. Most of the proposed structures have higher lead content, which somehow remains hazardous for nature. We in this work report our results for a low bandgap (1.2eV) mixed Sn (50%) and Pb (50%) halide (MAPb
0.5
Sn
0.5
I
3
) perovskite solar cell (PSC) structure to obtain 19.46% power conversion efficiency (PCE). For this work combination of C
60
(Buckminsterfullerene) and IC
60
BA (Indene-C
60
Bisadduct) and PEDOT: PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) have been used as electron transport layer (ETL) and hole transport layer (HTL) respectively. First, the PSC under consideration is calibrated in accordance with the experimental work with an efficiency of 13.57%. Followed by the optimization of material quality in terms of total bulk defect density (from 1x10
¹⁰
cm
^-3
to 1x10
¹⁵
cm
^-3
). The device reflected optimized conversion efficiency of 19.46% with PV parameters: JSC (23.01 mA.cm
^-2
), VOC (1.216 V) and FF (69.52%) at defect density of the order of 1x10
¹⁰
cm
^-3
. Results obtained here may pave the way for the extension of this work for tandem device structures as well.