Tailored Plasmons in Pentacene/Graphene Heterostructures with Interlayer Electron Transfer.

Area of Science:

• Materials Science
• Nanotechnology
• Condensed Matter Physics

Background:

• Van der Waals (vdW) heterostructures, assembled from 2D materials, exhibit unique properties.
• Graphene's Dirac Fermions support surface plasmons, crucial for nano-optical applications.

Purpose of the Study:

• To investigate the nanoplasmonic response of graphene in vdW heterostructures with pentacene.
• To understand the influence of molecular layer deposition on graphene plasmons.

Main Methods:

• Fabrication of vdW heterostructures by depositing pentacene on graphene.
• Nanoscale infrared (nano-IR) imaging to study surface plasmon behavior.
• Density functional theory (DFT) calculations for theoretical analysis.

Main Results:

• Graphene surface plasmons exhibit high sensitivity to adjacent pentacene layers.
• Plasmon wavelength shows a systematic, nonlinear decrease with increasing pentacene thickness.
• Electron transfer from pentacene to graphene is identified as the primary cause for the observed thickness dependence.

Conclusions:

• Interlayer coupling in vdW heterostructures significantly impacts graphene plasmonics.
• Pentacene-graphene vdW heterostructures offer a tunable platform for manipulating graphene plasmons.
• This work advances understanding of nano-optical phenomena in novel 2D material systems.