Light‐Tunable Nonvolatile Memory Characteristics in Photochromic RRAM

Light‐tunable resistive switching (RS) characteristics are demonstrated in a photochromophore (BMThCE)‐based resistive random access memory. Triggered by nondestructive ultraviolet or visible light irradiation, two memory‐type RS characteristics can be reversibly modulated in the same device upon a narrow range of applied voltage (<6 V), accompanied by the photochromophores in the active layer reversibly changed between ring‐open state (namely, o‐BMThCE) and ring‐closed state (namely, c‐BMThCE). The o‐BMThCE‐based memory exhibits a write‐once‐read‐many characteristic with a high current on/off ratio of 105, while the c‐BMThCE‐based one shows a flash characteristic. Both of the RS characteristics present good nonvolatile stability with the resistance states maintained over 104 s without variation. This RS modulation is possibly related to the formation and rupture of conductive filaments, which formed along channels consisting of BMThCE trapping molecules. This work provides a new memory element for the design of light‐controllable high density storage and data encryption technology.