Improved p-i-n MAPbI perovskite solar cells via the interface defect density suppression by PEABr passivation.

Organic-inorganic hybrid perovskite solar cells (PSCs) are promising candidates for next-generation photovoltaics due to their excellent optoelectronic properties and process compatibility. In this report, numerical simulations show the effect of perovskite surface defect density on the inverted MAPbI perovskite device. The Phenethylammonium bromide (PEABr) is introduced to passivate the MAPbI layer surface of the perovskite solar cell devices, PEA diffuses into the grain boundaries of the 3D perovskite to form 2D/3D hybrid structure during the thermal annealing process, thus improve the surface morphology and decrease the interface defects between MAPbI layer and PCBM layer. The power conversion efficiency (PCE) of the PSCs increased from 17.95% to 19.24% after PEABr treatment. In addition, the 2D/3D hybrid structure can also hinder the intrusion of water and oxygen, the stability of perovskite devices has been greatly improved.