Modulable hysteresis behavior controlled by water-promoted decomposition in a single CH3NH3PbI3 micro/nanowire

Abstract The instability of hybrid organic-inorganic perovskites (HOIP) in environment, especially in high humidity causes different conductance that should be addressed to improve its large-scale application and development. Here, the electrical transport of an individual CH3NH3PbI3 micro/nanowire-based two-terminal device with encapsulating different ends was investigated in a condensed water environment. For an unencapsulated device, linear I-V curve transforms first into two symmetrical counterclockwise hysteresis loops with positive resistive switching (RS) feature, and eventually converts into two symmetrical clockwise hysteresis loops with negative RS feature. For the device encapsulated at one end, the linear I-V curve first transforms into two symmetrical counterclockwise hysteresis loops with positive RS behavior, and then converts into two antisymmetric hysteresis loops with a bipolar RS feature. The origin of modulable hysteresis with different RS characteristics is mainly from the decomposition-induced decrease of surface states and formation of PbI2 and structure defects. As a consequence, the electrical field-triggered filling and emptying of traps in different regions dominate the adjustable performance of electrical transport. The controllable electrical transport can not only demonstrate clearly that condensed water can promote the decomposition of CH3NH3PbI3, but also verify that the hysteresis behavior with different RS memory effect originate from the decomposition-induced traps.