Localized surface plasmon resonance-induced charge carrier localization at the silver nanoparticle/graphene quantum dot interface

Abstract

We report a novel investigation into the effects of localized surface plasmon resonance (LSPR) on charge carrier localization and dynamics, utilizing a test structure where pentacene is layered over a graphene quantum dot (GQD) film. To induce LSPR, we strategically embedded silver nanoparticles (Ag NPs) between the pentacene and GQD films. This configuration led to a notable shift in the threshold voltage when the structure was illuminated at a resonance frequency of 450 nm. This shift is primarily attributed to the LSPR-induced charge transfer occurring at the interface between the Ag NPs and the GQD film. Remarkably, following the discontinuation of illumination, there was a noticeable and gradual release of electrons previously localized at the Ag NP/GQD interface. This phenomenon demonstrated effective retention of electrons at the interface, which subsequently led to an enhancement in the field-effect transistor (FET) mobility. This enhancement in the FET mobility is likely due to the diminished Coulombic interaction between the localized electrons and the mobile hole carriers within the pentacene channel.“