A metastable small organic molecule for secure memory devices

Recently, it has become highly desirable to prepare an active material or/and memory device, which can achieve not only data storage but also secure memory devices. Considering that small organic molecules display tunable properties and designable structures, a molecule PFTCM with a strong donor–acceptor structure containing electron donative pyrene, bridge chain functional group fluorene, and electron-withdrawing group dicyanomethylene indecanone was designed and synthesized. The current–voltage measurements of ITO/PFTCM/Al devices display the WORM memory behavior with a retention time of 10 000 s and a high ON/OFF ratio (107). When the sandwiched memory device is at the on state, the thin film is irradiated under the 365 nm light for 20 min. The curve goes from the ON state to the OFF state, suggesting that the storage performance disappears after UV irradiation due to the breaking of the molecules. Consequently, memory devices based on ITO/PFTCM/Al can achieve data storage and secure memory devices.