Transport Layer Material and Thickness Optimization of Cs₂TiBr₆ Based Solar Cell

Although perovskite solar cell is seeing tremendous success as a solar cell of third-generation, toxicity and stability are two significant obstacles that it needs to overcome yet. To triumph over these two challenges, an inorganic lead-free and nontoxic perovskite Cs
2
TiBr
6
has been presented to have impressive environmental stability and excellent photoelectric properties as a direct bandgap material, confirmed from various experiments recently. This work investigates the solar cell with FTO/ETL/Cs
2
TiBr
6
/HTL/Au structure and conducts simulation studies in the most crucial device physics aspects to improve the performance. By determining viable electron-hole transport layer, this study suggests an optimum thickness of 245 nm for the perovskite absorber layer in FTO/TiO
2
/Cs
2
TiBr
6
/MoO
3
/Au structure to possess a power conversion efficiency (PCE) of 15.02%. And this optimum thickness of the absorber increases dramatically with diffusion length. The findings of this study provide insight into the much higher impact of defect densities and diffusion length than transport layers (HTL& ETL).