Molecularly Engineered Wing-Shaped Azobenzene Memristors for Logic-in-Memory and Edge Visual Intelligence

Organic molecular resistive memory offers a promising platform to overcome the von Neumann bottleneck. Here, we report four symmetric azobenzene-based small molecules with diverse terminal substituents (nitroimidazole, imidazole, carbazole, and triphenylamine) for memristive applications. By tuning the terminal groups, the devices exhibit tunable nonvolatile behaviors-ranging from ternary/binary WORM to bipolar nonvolatile resistive memory-all featuring high ON/OFF ratios, low operating voltages, and excellent stability. Mechanistic studies reveal that charge-transfer-induced conformational changes govern the twisted intramolecular charge-transfer states, dictating these distinct memory characteristics. Notably, the Cz-methylene-Azo memristor demonstrates continuous conductance tunability and essential synaptic functions (e.g., excitatory postsynaptic current (EPSC), paired-pulse facilitation (PPF), long-term potentiation/depression (LTP/D)). Furthermore, it serves as a versatile logic-in-memory unit, executing multiple logic gates (OR, AND, XOR, NAND, etc.), the half and full-adder circuits. Its applicability for in-memory computing is successfully validated via convolutional neural networks (CNN)-based image edge detection, highlighting its great potential for next-generation integrated organic neuromorphic architectures.