Gold nanoparticles as a floating gate in Pentacene/PVP based MIS memory devices

Abstract

We report on the fabrication and characterization of a pentacene and poly(4-vinyl phenol) (PVP) based metal-insulator-semiconductor (MIS) memory structures. The surface morphology of pentacene grown on a thin layer of PVP showed the largest polycrystalline grains as compared to other dielectric materials such as polymethyl metacrylate (PMMA) or SU8. The effect of larger grain size of pentacene was reflected in the capacitance-voltage (C-V) characteristics of the devices, where devices with larger pentacene grains showed lower operating voltages and a steeper slope of the depletion region of the C-V curve. The introduction of solution-processed gold nanoparticles (AuNPs) embedded within the PVP layer induced the memory characteristics as it served as a floating gate in the MIS AIJPVP/AuNPs/PVP/Pentacene/Au structure. The C-V characteristics of the memory devices exhibit a clockwise hysteresis due to the charging and discharging of AuNPs from the aluminium gate through the PVP insulator layer. A memory window of 8.SV was achieved at a ±lOV voltage sweep range; wider memory windows were achieved at higher voltage sweep ranges. The memory devices have hysteresis centred close to OV and a short depletion region which make it favourable for low voltage and fast operation in organic and flexible electronics applications.