Memory performance of a thin-film device based on a conjugated copolymer containing fluorene and chelated europium complex

A memory device based on the sandwiched structure of a conjugated copolymer (PF8Eu), containing fluorene and chelated europium complex, has been fabricated. An electrical bistability phenomenon was observed on this device: low conductivity state for the as-fabricated device and high conductivity state after device transition by applying a voltage of /spl sim/3 V. At the low conductivity state, the device showed a charge injection controlled current and at the high conductivity state, the device showed a space charge limited current. At the same applied voltage, the device exhibited two distinguishable conductivities with an ON/OFF current ratio as high as 10/sup 6/ at room temperature. After transition to the high conductivity state, the device tended to remain in the high conductivity state even when the applied voltage was removed. Thus, the device is a potential write-once-read-many-times memory device.