Origin identification and accuracy control of electrode interface-related asymmetrical hysteresis in light-controlled resistive switching of single CH3NH3PbI3 micro/nanowire

Abstract

Remarkable photoresponse and resistive switching (RS) performance of CH3NH3PbI3 has garnered significant attention. However, precise control over the emergence and polarity of hysteresis loops in bipolar RS remains challenging. Herein, we constructed an individual CH3NH3PbI3 micro/nanowire device configured with two symmetrical Ag electrodes and asymmetrically modulated their electrode interface states by encapsulating only one electrode. We propose an electrode interface-related RS mechanism to modulate the hysteresis features and achieve different types of high-performance light-controlled RS. In an unpacked electrode interface, large potential induces oxidation of Ag to AgI with high resistivity under light and trace moisture, resulting in a high-resistance state. On the other hand, in a packed electrode interface, large potential triggers hole injection into interface traps with the assistance of light, resulting in a low-resistance state. Additionally, reversible Ag/AgI oxidation/reduction-related negative RS and hole injection/ejection-associated positive RS lead to bipolar RS, accompanied by clockwise and counterclockwise hysteresis loops in two directions. Furthermore, performance is entirely determined by illumination intensity and bias amplitude, achieving photomemory. This work unveils the influence of moisture and illumination on electrode interface and the actual origin of hysteresis, while also precisely controlling photomemory performance. Therefore, it provides a specific strategy for designing high-performance light-controlled RS with nonvolatile photomemory.