90% Yield Production of Spiropyran Covalently Grafted MXene‐Based RRAM Devices for Optoelectronic Dual‐Response Switching

Over the past decade, great efforts have been devoted to both intellectual property protection and information security protection. As a promising electroactive material, MXene is covalently or non‐covalently functionalized with organic species/polymers to produce a large amount of novel functional materials for biomedicine, optoelectronics, and energy storage. By using spiropyran covalently functionalized MXene (MXene‐SP) as an active material, an optoelectronic dual‐response resistive random access memory (RRAM) device is successfully fabricated. Upon UV illumination, the active layer is changed from MXene‐SP (SP: ring‐closed spiropyran form) observed under the illumination of blue light to MXene‐MC (MC: ring‐opened merocyanine form) due to photo‐induced “close‐to‐open” isomerization. The as‐fabricated ITO/MXene‐SP/ITO device exhibits typical nonvolatile optoelectronic dual‐response RRAM performance, with a production yield exceeding 90%. The achieved switch‐on/off voltages are −1.25/2.07 V under the illumination of blue light and −0.58/0.91 V under UV illumination. The switching bias window (Δ| V ON − V OFF |) and the ON/OFF current ratio of MXene‐MC are 44.9% and 14.7% of these of MXene‐SP, respectively. By utilizing the window difference between the RRAM performance achieved under the illumination of different lights, one can easily encrypt the quick response code.