Light-modulated transparent memristors combining photoresponse and data storage are promising as multifunctional devices. Herein, a multicolor light-modulated transparent memristor based on black phosphorous (BP) is designed, fabricated, and investigated. BP is a class of emerging two-dimensional (2D) materials with a natural direct band gap and a broad light absorption. Herein, BP nanosheets (BP@PS NSs) coated with polystyrene (PS) are prepared and serve as the resistive switching (RS) layer in the ITO/BP@PS/ITO memristor, which shows >75% transmittance between 350 and 1100 nm. With the aid of PS, the BP@PS-based memristor has excellent RS characteristics such as no initial preforming, low operating voltage, and long retention time. According to the energy band model, the RS mechanism of the high and low resistance states contributes to the transformation from ohmic contact to Schottky contact. During light illumination ranging from ultraviolet (380 nm) to near infrared (785 nm), the Schottky barrier height is elevated further so that the resetting voltages and power consumption decrease. Moreover, the ON/OFF ratios are improved and the maximum enhancement is demonstrated to be more than 10 times. BP is a promising RS material in light-modulated memristors, and the novel device configuration provides insights into the development of multifunctional microelectronic devices based on 2D materials.
Keywords: black phosphorous; light-modulated; memristor; resistive switching; two-dimensional material.