Improved Environmental Stability of Cobalt Incorporated Methylammonium Lead Iodide Perovskite for Resistive Switching Applications

Abstract In the present report, we studied the effect of partial substitution of Pb2+ by Co2+ on environmental stability and performance of methylammonium lead iodide (MAPbI3) based resistive switching (RS) device. The substitution of Co2+ enhances the environmental stability of MAPbI3 thin films and their RS performance. Raman spectroscopy and density functional theory (DFT) calculations further revealed that the Co2+ substituted MAPbI3 thin films show improved environmental stability compared to undoped MAPbI3 by increasing the strength of hydrogen bonds formed between inorganic octahedra and organic cation (I.....H). The Co2+ substitution (5 at%) lowers the switching voltage and increase the separation between high resistance state (HRS) and low resistance state (LRS) currents of the RS device compared to undoped MAPbI3 device. The scanning electron microscopy (SEM) results indicate that the substitution of Co2+ also enhances the uniformity and compactness of MAPbI3 films, leading to improved performance of the RS device.