Asymmetric Bipolar Resistive Switching of Halide Perovskite Film in Contact with TiO2 Layer.

摘要: Halide perovskite materials such as methylammonium lead iodide (CH3NH3PbI3) have attracted considerable interest for the resistive random-access memory applications, which exploit a dramatic change in resistance by an external electric bias. In many semiconductor films, drift, accumulation, and chain formation of defects explain This study demonstrates that interface CH3NH3PbI3 with TiO2 has significant impact on rupture defect chains causes asymmetric bipolar switching Au/CH3NH3PbI3/TiO2/FTO device (FTO = fluorine-doped tin oxide). When negative bias is applied to Au electrode, iodine interstitials lowest migration activation energy move toward layer pile up at CH3NH3PbI3-TiO2 interface. Under same condition, oxygen vacancies also travel strongly attract interstitials. As result, Schottky barrier appears interface, becomes much larger than Au/CH3NH3PbI3/FTO high state. The frequency dependence capacitance confirms appearance large space charge polarization unique behavior on/off ratio (103) retention time (>104 seconds) -0.85 V film.