Simulation and Optimization of a solar Cell Based on the Double perovskite Absorber Material Cs2BiAgI6

This work concerns the simulation and optimization of the structure of the solar based on the non-toxic, inorganic, double perovskite absorber Cs
2
BiAgI
6
, having a gap of 1.6 eV. The architecture of the basic cell is configured as follows: PCBM/Cs
2
BiAgI
6
/PTAA, where the PCBM and PTAA materials represent the electron and hole transport layers, ETL and HTL respectively. These layers were carefully chosen based on their mobility and bandgap shift relative to the absorbing layer. The model used in the simulation shows the impact of the recombination rate at the interfaces and the defect density in the perovskite layer on the device performance. The variation of the photovoltaic parameters of the cell as a function of the thickness of the different layers ETL, Absorber and HTL was evaluated. The results showed that when the recombination rate at the S
n
and S
p
interface does not exceed 100 cm/s, and the defect density does not increase beyond 10
¹⁴
cm-3, an efficiency of 20% is obtained for the following optimal thicknesses: 50 nm, 1.2 μm and 100 nm of the ETL, Absorber and HTL layers respectively. An improvement is observed compared to the basic configuration. It is noted that a conversion efficiency of 19.97% is obtained using inorganic TiO
2
and Cu
2
O layers as ETL and HTL, for the same previous thicknesses, the same absorber defect density and the same interface recombination rates.