Performance of 2-D/3-D Mixed-Dimension Tin Perovskite Solar Cells and Their Prospects Under Bifacial Configuration

This work focuses on the design and development of lead-free halide perovskite solar cells (PSCs). Here, 3-D and 2-D/3-D mixed-dimension tin PSCs have been fabricated by adding phenylethylammonium iodide (PEAI) in varying quantities. A maximum power conversion efficiency (PCE _$|$MAX ) of 11.03% has been obtained at a PEAI concentration of 15%, with indium tin oxide (ITO) and Ag as the front and rear electrodes, respectively. Addition of PEAI has also improved the stability of the solar cells. Using the measured properties from this device, monofacial and bifacial designs for the same material stack has been simulated by using suitable rear electrodes, without changing the front electrode. Silvaco 2-D TCAD software has been used for this purpose. With Ag and ITO as rear electrodes, the monofacial designs gave PCE _{$|$ MAX} values of 17.94% and 12.79%, respectively. On the other hand, the bifacial design with a concurrent AM1.5G illumination of 1 sun intensity, the device gave a PCE _{$|$ MAX} of 26.55%. The study also examined the impact of albedo effects from various reflecting surfaces on the performance of this bifacial perovskite solar cell (BPSC). Notably, snow albedo positively influenced efficiency of the BPSC, increasing it by 38.85% compared with that of monofacial perovskite solar cell (MPSC) with Ag rear electrode. Conversely, albedos from soil, seawater, and pond water resulted in lower efficiencies, even falling below those of MPSCs with Ag back electrodes. These results indicate that bifacial design has the potential to be an efficient and cost-effective solution for tin-based PSCs.