Synergistic combination of DJ 2D-3D Layers: Achieving 30.75 % perovskite solar cell efficiency

Abstract

Perovskite solar cells (PSCs), despite progress in times, face challenges related to their long-term stability owing to moisture, which poses a significant hurdle for their widespread commercial adoption. The progress in this field has brought two perovskites that show enhanced stability by merging organic cations and inorganic layers in an alternating pattern. The 2D perovskites are of two types: one is the Ruddlesden-Popper (RP) phase and the other is Dion-Jacobson (DJ) phase. These two phases are more stable than normal 3D perovskites. Both 2D phases are incorporated together to give further stabilization and enhanced performance to a solar cell when coexistence is forecasted. The DJ phase has a compact structure where the inorganic layers are directly accumulated on top of one another, while in the RP phase, there is a layer of organic cations between each inorganic layer, creating a larger interlayer distance. Due to this closer spacing in the DJ phase, charge carriers can move more efficiently through the material, resulting in better conductivity. A theoretical study has been conducted for PSCs, which are constructed as FTO/ZnO/CH₃NH₃PbI₃/PeDAMA₃Pb₄I₁₃/Cu₂O/Au. In the mentioned structure, CH₃NH₃PbI₃ is the 3D layer, which has a band gap of 1.58eV, and PeDAMA₃Pb₄I₁₃ is used as the 2D layer, with a band gap of 1.76eV, while FTO is light-harvesting layer with ZnO acting as an electron transport layer (ETL) and Cu₂O acts as a hole transport layer (HTL). Some selected ETL and HTL configurations were run using SCAPS-1D software. The proposed PSC structure shows a PCE of 30.75 % under high temperatures and moisture. The results, together with the excellent stability of DJ 2D perovskites due to the tighter packing, suggest that they can be considered potential candidates for PV applications. The short-circuit Current Density (J_SC) of 22.8 mA/cm², along with a Fill Factor (FF) of 86 % and Open-circuit Voltage (V_OC) of 1.56 V shows their good potential of outperforming 3D perovskites simultaneously for efficiency and durability in adverse conditions.