Influence of blending ratio on resistive switching effect in donor-acceptor type composite of PCBM and PVK-based memory devices

摘要

The influence of blending ratio on resistive switching effect in donor-acceptor type composite of [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) and poly(N-vinylcarbazole) (PVK)-based memory devices are investigated. Current-voltage (I-V) curves for the ITO/PCBM + PVK/Al devices with 9 wt.% of PCBM showed a current bistability with a maximum OFF/ON resistance ratio of 9 x 10(4), which was 100 times larger than that of the device with 23 & wt.% of PCBM and was 2000 times larger than that of the device with 41 & wt.% of PCBM. Furthermore, the threshold voltage obviously decreased as the PCBM concentration increases. The retention time was above 10(5)& s indicative of the memory stability of the as-fabricated devices. The I-V characteristics at OFF state dominantly comply with the rules of space-charge-limited-current behaviors, and I-V curve at ON state obey Ohmic laws. The proposed device suggests a promising approach for adjustale OFF/ON resistance ratio and threshold voltage in electronic memory devices.