Resistive switching memory devices based on organic as
well as
organic–inorganic hybrid materials are emerging as viable candidates
for post-Moore nonvolatile memory applications. In this article, we
report a nonvolatile write-once-read-many (WORM) resistive switching
memory device (Al/7HNO3C/ITO) based on a coumarin derivative 7-hydroxy-N-octadecyl
coumarin-3-carboxamide (7HNO3C). The device yield, retention time,
read endurance, and memory window of the designed memory device were
found to be 36.11%, 4 × 103 s, 1270 cycles, and ∼102, respectively. ZnO nanoparticles were synthesized and incorporated
into the active layer of the coumarin-based device in order to enhance
the memory performance of the device. The ZnO-incorporated device
showed overall improvement in terms of device yield (83.33%), retention
time (experimentally 3 × 104 s, extrapolated 10 years),
read endurance (9930 cycles), and memory window (∼103) along with a significant decrease in the device-to-device variability.
Moreover, density functional theory (DFT) studies and temperature-dependent
measurements have revealed that charge transfer and oxygen vacancy
filament formation were the key mechanisms behind such an observed
memory behavior.