Bistable electrical switching and nonvolatile memory effect in mixed composite of oxadiazole acceptor and carbazole donor

Abstract

Bistable electrical switching and nonvolatile memory devices with the configuration of indium tin oxide (ITO)/active layer/aluminum (Al) are reported. The active layer were prepared from the mixed compositions of 2-(4-tert-butylphenyl)-5-(4-biphenylyl)-1,3,4-oxadiazole, (PBD) and poly(N-vinylcarbazole) (PVK). The as-fabricated ITO/PBD:PVK/Al sandwiched devices exhibited rewriteable flash memory property. Due to the strong interaction between oxadiazole acceptor and carbazole donor, the devices demonstrate excellent performance. The memory devices can operate over a small voltage range, the absolute value of switching-on threshold voltage is less than 1V and the switching-off threshold voltage is less than 3.5V. The ON/OFF ratio of current switches in the range of 104–102 during the variation of applied voltage and the two different resistance states can be maintained over 4h.