Development of indigo-based nonvolatile write-once-read-many-times memory device

The development of a nonvolatile organic write-once-read-many-times (WORM) memory device, consisting of a 100 nm layer of indigo sandwiched between indium tin oxide cathode and Al anode, is reported. This device is found to be at its ON state and can be switched to the OFF state by applying a positive bias with the ON/OFF current ratio being up to 106. The device exhibits storage stability of over 108 h in air without encapsulation. This device offers the possibility of a low-cost biodegradable data storage as Indigo is inexpensive, bio-degradable and non-toxic. The operational mechanism of the device is discussed in terms of dipoles induced at the Al-indigo interface.