Multiple-trapping in pentacene field-effect transistors with a nanoparticles self-assembled monolayer

A silver nanoparticles self-assembled monolayer (SAM) was incorporated in pentacene field-effect transistor and its effects on the carrier injection and transport were investigated using the current-voltage (I − V) and impedance spectroscopy (IS) measurements. The I − V results showed that there was a significant negative shift of the threshold voltage, indicating the hole trapping inside the devices with about two orders higher in the contact resistance and an order lower in the effective mobility when a SAM was introduced. The IS measurements with the simulation using a Maxwell-Wagner equivalent circuit model revealed the existence of multiple trapping states for the devices with NPs, while the devices without NPs exhibited only a single trap state.