Nonvolatile unipolar and bipolar bistable memory characteristics of a high temperature polyimide bearing diphenylaminobenzylidenylimine moieties

This study reports the synthesis and properties (in particular, the electrical switching characteristics) of a new high-performance polyimide (PI), poly(3,3′-di(4-(diphenylamino)benzylidenyliminoethoxy)-4, 4′-biphenylene hexafluoroisopropylidenediphthalimide) (6F-HAB-TPAIE PI). This PI polymer bears diphenylaminobenzylidenylimine moieties as side groups and is dimensionally stable up to 280 °C and thermally stable up to 440 °C. In devices fabricated with the PI polymer as an active memory layer, the active PI polymer was found to operate at less than (2 V in electrically bistable unipolar and bipolar switching modes by controlling the compliance current. The PI polymer layer exhibits repeatable writing-reading-erasing capability with high reliability in ambient air conditions as well as at high temperatures up to 130 °C. This PI polymer also exhibits a high ON/OFF current ratio up to 10⁹. The observed nonvolatile memory behaviors are due to Schottky emission and local filament formation. This study has demonstrated that this thermally, dimensionally stable PI polymer is a promising material for mass production at low cost for high-performance, programmable, nonvolatile memory devices that can be operated with low power consumption in unipolar and bipolar switching modes.