High-Performance Nonvolatile Organic Transistor Memory Enabled by a Self-Assembled Edge-on Floating Gate

Nonvolatile floating gate memory has been demonstrated as one of the most promising data storage technologies, while the device performance is usually limited by the disordered morphology of the floating gate layer. Herein, the self-assembled films (SAFs) based on the conjugated core-coil organic molecules are successfully prepared by the "solution epitaxy" approach and are subsequently employed as the floating gate in the organic nonvolatile memory transistor. As revealed by GIWAXS, the SAFs exhibit distinct lamellar stacking diffractions along the out-of-plane direction, confirming the long-range ordered morphology with prominent edge-on molecular orientation. The uniform and defect-less surface of SAFs also facilitates the subsequent film-forming process of an overlying organic semiconductor layer, which affords a preferable crystalline pentacene film with continuous domains and fewer boundaries. Consequently, the resulting memory devices exhibit enhanced carrier injection and charge trapping capabilities, leading to an exceptional performance of large memory window (87 V), long-term charge retention, reliable endurance, and multilevel storage. These results demonstrate the superiority of highly ordered SAFs in charge trapping and storage, shedding more light on the development of high-performance organic memory devices by controlling the molecular arrangement.