Numerical Analysis on the Effect of the Conduction Band Offset in Dion–Jacobson Perovskite Solar Cells

Benefiting from the advantages of a high absorption coefficient, a long charge diffusion length, excellent carrier mobility, and a tunable bandgap, three-dimensional (3D) metal halide perovskites exhibit great potential for application in solar cells. However, 3D perovskite solar cells (PSCs) often suffer from poor long-term stability against moisture, heat, and light. To address this issue, reducing the dimension of perovskite and forming two-dimensional (2D) perovskites can be effective in slowing down the oxidation of the perovskite film and significantly improving device stability. In this study, 2D PSCs were designed with glass/FTO/TiO 2 /Dion–Jacobson (DJ) perovskite/NiOx/Au structures, based on the solar cell simulation software SCAPS. The absorption layers employed in the study included PeDAMA 2 Pb 3 I 10 , PeDAMA 3 Pb 4 I 13 , PeDAMA 4 Pb 5 I 16 , and PeDAMA 5 Pb 6 I 19 . The influence of the conduction band offset ( CBO ) variation in the range of −0.5 to 0.5 eV on cell performance was explored through a numerical simulation. The simulation results indicate that the open-circuit voltage and fill factor continue to increase, whereas the short-circuit current density remains almost unchanged when the CBO increases from −0.5 eV to 0 eV. The devices exhibit better performance when the value of the CBO is positive and within a small range. For DJ PSCs, controlling the CBO within 0.1–0.4 eV is conducive to better cell performance.