Tuning of electrical bistability in organic devices through electrochemical potential of metal contacts

The effect of different electrode combinations on conductance switching devices has been studied. A number of base electrodes were chosen while the top electrode was kept the same. With a suitable electrode combination, we could observe a large conductance switching (On/Off ratio = 107). Such a high ratio as compared to other electrode combinations has been discussed in terms of reversible electrochemical changes of charge transfer complexes and change in conduction mechanism. The switching devices showed an associated memory effect for data-storage applications. We could “write” or “erase” a state and “read” it for many cycles. The high On/Off ratio was maintained at the “read” pulse of “write–read–erase–read” sequence and also during long-time retention test. The results showed a novel route to select right electrode combination for efficient conductance-switching devices.