WORM-type memory device based on a conjugated copolymer containing europium complex in the main chain

A conjugated copolymer of 9,9-dihexylfluorene and Eu-complexed benzoate (PF6Eu) for write-once read-many-times (WORM) memory application was demonstrated in a sandwich structure of Al/PF6Eu/ITO. The device exhibited: a high ON/OFF current ratio up to 10(7), stable ON and OFF states with read cycles up to 10(8) at a read voltage of 1 V, and projected stability up to 10 years at a constant stress of 1 V. (c) 2006 The Electrochemical Society.