Realization of write-once-read-many-times memory devices based on poly(N-vinylcarbazole) by thermally annealing

A nonvolatile write-once-read-many-time (WORM-time) memory device based on poly(N-vinylcarbazole) (PVK) films was realized by thermally annealing. The device can be fabricated using a simple spin coat method. It was found that the control of PVK film surface morphology by thermally annealing plays an important role in achieving the WORM memory properties. The memory device showed an ON/OFF current ratio as high as 10(4) and the retention time was over 2000 s without degradation.