Reduced interfacial recombination losses and lead leakage in lead-based perovskite solar cells using 2D/3D perovskite engineering

Although perovskite solar cells (PSCs) have achieved significant success, there are still some barriers to their commercialization, such as poor stability and unsatisfactory power conversion efficiency (PCE). Here, we report low-dimensionality engineering of perovskites using mercaptoethylammonium iodide (MEMI). Two-dimensional (2D) perovskite materials can simultaneously passivate the interface defects of the perovskite film and enhance carrier extraction. The PCE of the device increased from 20.85% for the control device to a resultant of 22.41% for the target device. Meanwhile, device stability was ameliorated after MEMI modification, and the stability of unencapsulated target devices decreased by 7.5% after aging in the dark air condition for 300 h. Finally, the notorious lead leakage was significantly suppressed. This work guides to create efficient and stable environmentally friendly PSCs through low-dimensional engineering.