Achieving 24.6 % efficiency in 2D perovskite solar cells: Bandgap tuning and MXene contact optimization in (BDA)(MA)n−1PbnI3n+1 structures

In the midst of the growing emphasis on renewable energy sources, there is an urgent requirement for materials that are devoid of lead and non-toxic, aligning with the demands of the 21st century. In this regard, the perovskite solar cells present themselves as a compelling option, offering cost-effectiveness and non-toxic Nature. Nevertheless, these 3D perovskite materials encounter stability challenges. To mitigate these issues, 2D DJ (Dion Jacobson) perovskite material-based solar cells are increasingly utilized in contemporary applications. In this work, (BDA)(MA)n−1PbnI3n+1-based 2D DJ perovskite solar cells (BDPSC) are investigated. Further, it is crucial to use proper contact with BDPSC in order to eliminate the pinhole effect. Therefore, in this study, MXene contacts have been employed with BDPSC to combine the benefits of both, resulting in enhanced stability, superior charge transport, and tunable energy levels without pinhole effects. Further, the bandgap of the BDA active layer is adjusted by varying the number of inorganic layers (n) from 1 to 6 within the (BDA)(MA)n−1PbnI3n+1. Firstly, the thickness of the BDA active layer along with different MXene are varied for all the possible compositions of the (BDA)(MA)n−1PbnI3n+1. The result shows that the optimized thickness for the BDA layer is 1 µm, and the value of the left/right contact MXene is 3.56/5.65 eV. Additionally, this work also investigates the influence of grading on the PV performance of BDPSC. The result shows that the reported BDPSC can deliver a maximum VOC is 1.18 V, JSC is 24.58 mA/cm2, FF is 84.96 % and efficiency is 24.58 %.