Resistive Switching and Space-Charge-Limited Transport in Ag/α-Phase Patterned PVDF/Ag Devices Fabricated by Soft Imprint Lithography.

This research work explores the resistive switching behavior and the impact of geometric confinement on charge transport mechanisms of Ag/α-phase patterned Polyvinylidene fluoride (PVDF)/Ag and Ag/α-phase unpatterned PVDF/Ag devices. Uniform line and groove (L/G) patterns on a PVDF thin film were imprinted using the soft imprint lithography (SIL) technique, followed by the deposition of a silver (Ag) electrode via DC magnetron sputtering. Structural and surface characterizations were performed using confocal Raman spectroscopy, X-ray diffraction, and atomic force microscopy. The Ag/α-phase patterned PVDF/Ag devices exhibited multiple transitions at set voltages (34.2 V, 37.9 V and 49.6 V in forward bias; -12.0 V and -15.6 V in reverse bias) and reset voltages (-27.5 V and -46.3 V in reverse bias; 50.0 V in forward bias) across different junctions than the unpatterned devices. Current-voltage (I-V) characteristics revealed Ohmic conductivity at low fields, trap-filled space-charge-limited current (SCLC) at medium fields, and a transition to free-trap regimes at high fields, consistent with Geurst's trapped-SCLC model. These findings emphasize the potential benefits of α-phase PVDF thin films with L/G structure by the SIL technique for resistive memory and flexible electronic applications.