WORM Behavior of 6F-TPA PI by Hole Injection

Polymer memory devices have attracted considerable attention because of their advantages such as low cost potential, good scalability, flexibility, simplicity in structure, and large capacity for data storage. Metal/poly (4,4'-aminotriphenylene hexafluoroisopropylidenediphthalimide) (6F-TPA PI)/metal system has been found to show an electrical bi-stable behavior. Here, we show a novel set-up of 6F-TPA PI/Al sample in which holes are injected by photoelectron emission process instead of direct charge carrier injection via metal electrode. In this process, an irreversible electrical phase transition of 6F-TPA PI is found, leading to a write-once-read-many (WORM) behavior. The photoelectron spectroscopy results measured before and after the switching process revealed that the irreversible electrical phase transition of 6F-TPA PI is attributed to the chemical modification of the carbonyl group in phthalimide moiety.