Abstract <p>Tandem solar cells work collaboratively, with each layer of the cell being engineered to capture a particular segment of the solar spectrum. This enables it to harness a greater portion of the sun’s energy than conventional solar cells. Tandem solar cells offer a significant step toward achieving better power conversion efficiency (PCE) than conventional single-junction cells. This paper models a two-layer tandem cell, with the activity of the top (T_CELL) and bottom (B_CELL) sub-cells being determined mainly by the bandgap energies of the absorber materials. The T_CELL has a Dion–Jacobson configuration, which consists of a two-dimensional (2D) layer of perovskite (PeDAMA₄Pb₅I₁₆, Eg = 1.65&#xa0;eV) and a three-dimensional (3D) layer of perovskite (FAPbI₃). This design combines the stability of 3D perovskites with their enhanced theoretical performance. The B_CELL is based on a narrow-bandgap halide (NBH) with the perovskite composition FA_0.7MA_0.3Pb_0.5Sn_0.5I₃, CIGS, and Si with bandgaps of 1.22, 1.30, and 1.12&#xa0;eV, respectively. Simulations were performed with standard AM1.5 conditions (1000 W/m², 300&#xa0;K), ideal R_S, and R_SH of 10⁵Ω-cm². In isolation, the T_CELL recorded a PCE of 22.36% (V_OC = 1.37&#xa0;V, J_SC = 20.36&#xa0;mA/cm², FF = 70.96%), whereas the B_CELL (perovskite [PVSK]-based), B_CELL(CIGS-based), and B_CELL(c-Si-based) had stand-alone PCE of 23.15%, 18.46%, and 31.15%, respectively. Using spectral filtering and current matching, the integrated tandem cell displayed significantly higher performance, with PCE of 32.02% for the silicon-based B_CELL. This study affirms that tandem solar cells stand among the most promising approaches to advancing solar energy toward a brighter and more efficient future.</p> Graphical Abstract <p></p>