Molecule-based multilevel memory devices attract increasing attention because of their tunable electronic properties and potential for miniaturization in device design. The recent use of organic molecules with chemically tunable electron acceptor “traps” raises great hopes for this area.

Jianmei Lu and colleagues, Soochow University, Suzhou, China, designed three different O-fluoroazobenzene (FAZO)-based molecules with different donor-acceptor structures and high thermal stability as memory active molecules. The team incorporated the compounds into sandwich devices with indium tin oxide (ITO) glass and aluminum or gold. The fabricated ITO/FAZO-1/Al (Au) and ITO/FAZO-2/Al (Au) memory devices both exhibited volatile static random access memory (SRAM) behavior, while the ITO/FAZO-3/Al (Au) device showed nonvolatile ternary write-once-read-many-times (WORM) behavior.

The different memory performances of these materials were determined by the stability of electric field-induced charge-transfer complexes. This approach provides a useful strategy for the design of organic memory materials with donor-acceptor structures.

• Improving memory performances by adjusting the symmetry and polarity of O-fluoroazobenzene based molecules,
  Jian-Mei Lu, Quan Liu, Huilong Dong, Youyong Li, Hua Li, Dongyun Chen, Lihua Wang, Qingfeng Xu,
  Chem. Asian J. 2015.
  DOI: 10.1002/asia.201501030