Related Experiment Video
Updated: Mar 8, 2026
11:42
Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
Published on: July 24, 2015
16.2K
Broadband terahertz modulation in electrostatically-doped artificial trilayer graphene
Ioannis Chatzakis1, Zhen Li1, Alexander V Benderskii2
1Department of Electrical Engineering, University of Southern California, Los Angeles, California, CA 90089, USA. ioannis.chatzakis.ctr.gr@nrl.naval.mil ioannis.chatzakis@gmail.com scronin@usc.edu.
Nanoscale
|January 17, 2017
Summary
We developed a terahertz optical modulator using trilayer graphene (TLG). This device modulates terahertz transmission by tuning the graphene
Area of Science:
- Optoelectronics
- Materials Science
- Condensed Matter Physics
Background:
- Terahertz (THz) optical modulators are crucial for THz technology.
- Graphene's unique electronic properties offer potential for THz device applications.
- Previous THz modulators often face limitations in bandwidth or efficiency.
Purpose of the Study:
- To investigate the performance of a trilayer graphene (TLG) based THz optical modulator.
- To explore the modulation mechanism based on Fermi level tuning in TLG.
- To assess the influence of the silicon substrate on THz modulation.
Main Methods:
- Fabrication of a TLG device on an oxidized silicon substrate.
- Characterization using THz-Time Domain Spectroscopy (THz-TDS).
- Electrical gating to tune the Fermi level and measure THz transmission changes.
Main Results:
- Achieved a 15% modulation in THz transmission over a broad frequency range (0.6-1.6 THz).
- Observed strong absorption (>80%) and frequency-independent conductivity in TLG.
- Demonstrated significant THz modulation from the silicon substrate itself under applied bias.
Conclusions:
- Trilayer graphene is a viable material for efficient THz optical modulators.
- The silicon substrate plays an active role in THz modulation, offering new design possibilities.
- This work advances the development of tunable THz devices.
