Enhanced resistive switching behavior of CH3NH3PbI3 based resistive random access memory by nickel doping

Excessive iodine vacancies (V(I)s) in the methylammonium lead halide perovskites (MAPbI(3)) based resistive random access memories (RRAMs) will cause resistive switching (RS) performance degradation. In this study, nickel ions are utilized to limit the excessive V(I)s in MAPbI(3) film. Based on the analysis of X-ray diffraction and X-ray photoelectron spectroscopy, it can be found that the doped nickel ions partially replace lead ions, which can effectively improve lattice integrity and suppress generating of the PbI2 and Pb-0 to limit excessive V(I)s. The RRAM devices based on MAPbI(3) and Ni doped MAPbI(3) films as the resistive switching layer are fabricated in air atmosphere. Compared with the MAPbI(3) device, the Ni doped MAPbI(3) device shows more remarkable RS performance. The ON/OFF ratio and endurance of the Ni doped MAPbI(3) device has reached 10(3) and 300 cycles. Moreover, illumination in the forming stage can further improve the ON/OFF ratio and endurance of the Ni doped MAPbI(3) device to 10(4) and 400 cycles. This work provides a new method for the optimization of organic-inorganic hybrid perovskite RRAM with high ON/OFF ratio and stable endurance.