NH4F as an interfacial modifier for high performance NiOx-based inverted perovskite solar cells

Inverted perovskite solar cells with NiO x hole transport layer (HTL) have attracted abundant attention due to low-cost fabrication and high device-efficiency. However, the further development of NiO x -based inverted perovskite solar cells (PSCs) would be restricted by the unsatisfactory electrical properties in pristine NiO x and the non-ideal charge transfer between perovskite and NiO x . In this work, a facile and effective method was designed to regulate the electronic property of NiO x HTL and make an alteration to the interface between the perovskite and NiO x . NH 4 F was used as an interfacial modifier to enhance the charge transfer between the perovskite layer and NiOx. The NiO x -F layer was generated with high transmittance and low trap density . Besides, the power conversion efficiency of the device was improved from 17.17% to 18.94% with the improvement of short-circuit current (J sc ) by using the structure of ITO/NiO x /NH 4 F/MAPbI 3 /PCBM/BCP/Ag. Finally, the device with NH 4 F exhibited better stored stability in the dry condition compared with the control device.