Organolanthanides complexes for organic memory devices applications

Organic Memory Devices (OMD's) are a relatively new class of organic semiconductors devices which appear highly attractive due to their potential application in data storage. Blends of several organometallic compounds, lanthanide (Ln3+) beta-diketonate complexes (Ln3+= Eu3+, Gd3+, Sm 3+) in poly(vinyl)carbazole have been investigated as promising candidates for OMD. A single layer cell is obtained by an active layer sandwiched between two electrodes (ITO and Al). It was found experimentally that devices exhibited two distinctive bistable conductivity states, and are then suitable as WORM (Write Once Read Many) memory devices, only if the chemical structure of the ligand used was able to allow the reduction of the Ln3+ ion with the formation of charge transfer complexes. It is also noteworthy to note that a proper choice of the electrodes was able to change the intrinsic characteristic of the memory device then a flash rewritable memory can be obtained. A complete characterization and a deep investigation of the properties and performances of different materials as memory devices will be presented. Moreover the role of the different Ln3+ ions will be discussed.