Application of Graphene in Acoustoelectronics.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Acoustics

Background:

• Lithium niobate (LiNbO3) is a key material for surface acoustic wave (SAW) devices.
• Traditional interdigital transducers (IDTs) can be limited by their mass and conductivity.
• Graphene offers unique electronic and mechanical properties for advanced device fabrication.

Purpose of the Study:

• To fabricate and characterize a novel multilayer graphene (MLG) interdigital transducer (IDT) on LiNbO3.
• To investigate the impact of graphene IDTs on surface acoustic wave (SAW) excitation and velocity.
• To explore the potential of graphene as a replacement for traditional IDT materials.

Main Methods:

• Multilayer graphene synthesis via Chemical Vapor Deposition (CVD).
• Graphene transfer onto YZ-cut LiNbO3 substrates.
• Electron beam lithography (EBL) and plasma chemical etching for IDT patterning.
• Raman spectroscopy for graphene characterization.
• SAW delay line measurements for amplitude-frequency response analysis.
• Scanning electron microscopy (SEM) for visualizing SAW excitation.

Main Results:

• Successfully fabricated MLG-IDT structures with a wavelength of 60 μm on LiNbO3.
• Characterized MLG properties using Raman spectroscopy.
• Measured SAW delay time line amplitude-frequency response.
• Observed an increase in SAW velocity attributed to the minimized mass of the graphene IDT.
• Visualized SAW excitation process using SEM.

Conclusions:

• Multilayer graphene is a viable material for fabricating high-performance IDTs on LiNbO3.
• Graphene IDTs enable enhanced SAW velocity due to reduced transducer mass.
• This work demonstrates a promising approach for next-generation SAW devices with improved performance.