Graphene
CA two-dimensional carbon lattice with notable electronic, optical, mechanical and thermal properties.
GRAPHENE · 2D MATERIALS · PHOTONICS
When matter becomes one layer, physics begins again.
2DSYS explores graphene, the physics of two-dimensional materials, and their emerging applications in photonics, sensing, and future technologies—with a focus on the research of Dr. Maryam Riyahi.
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01 / FUNDAMENTAL PHYSICS
One layer, entirely different behaviour
Graphene is a two-dimensional arrangement of carbon atoms in a honeycomb lattice. Reducing matter to the scale of a single atomic layer gives rise to electronic, optical, mechanical and thermal behaviour that is not seen in the same way in bulk materials.
i The honeycomb lattice
Carbon atoms in graphene form covalent in-plane bonds arranged in a hexagonal network built from two equivalent sublattices, so the unit cell contains two atoms. That symmetry is the starting point for much of graphene's electronic behaviour.
ii Charge carriers and the Dirac cone
In ideal graphene the relation between energy and momentum near the Dirac point is close to linear rather than the usual parabolic form. Charge carriers therefore behave much like particles with no rest mass, and the Fermi level can be shifted with a gate voltage.
iii Light–matter interaction
Despite being one atom thick, graphene absorbs roughly 2.3% of normally incident light across a broad part of the visible spectrum — a value set by the fine structure constant. That strong, broadband interaction is what makes graphene attractive for photonic structures.
iv Layer number, strain and environment
The properties of a two-dimensional material do not depend on its composition alone. The number of layers, how they are stacked and their relative angle, mechanical strain, the substrate and the surrounding environment can all change the electronic and optical response.
02 / THE MATERIAL LANDSCAPE
Beyond graphene: a family of atomic materials
h-BN
BNAn insulating two-dimensional material that can be used in heterostructures and as a dielectric layer.
TMDs
MX₂Transition metal dichalcogenides such as MoS₂, WS₂ and WSe₂, with semiconducting and optoelectronic behaviour.
Black Phosphorus
PA two-dimensional material with anisotropic behaviour and properties that depend on direction and layer number.
03 / FROM LAYERS TO SYSTEMS
From atomic structure to future systems
Integrated Photonics ON-CHIP
Placing two-dimensional layers on waveguides and optical resonators makes it possible to control the absorption and phase of light on a chip.
Optoelectronics LIGHT ↔ CHARGE
Converting light into an electrical signal and back again in structures whose active material is only a few atomic layers thick.
Advanced Sensors SURFACE RESPONSE
A very high surface-to-volume ratio means the material's response to changes in its surroundings can be measured with meaningful sensitivity.
Flexible Electronics MECHANICAL
Mechanical strength combined with extremely low thickness allows structures that tolerate bending.
Energy Systems STORAGE
Layered structures with a large effective surface area and useful conductivity are studied for energy storage and conversion.
Quantum & THz Technologies LOW-DIMENSIONAL
Low-dimensional structures provide a platform for studying discrete energy levels and interaction with radiation in the terahertz range.
04 / RESEARCH FOCUS
Research at the edge of photonics and 2D materials
Dr. Maryam Riyahi's research focuses on graphene, graphene photonics, the integration of two-dimensional materials with photonic systems, material characterization, and micro/nanofabrication processes.
Photonics
02
- 01Graphene PhotonicsLight–matter interaction in graphene
- 022D Material Integrated Photonics2D layers on photonic platforms
Characterization
04
- 03Raman SpectroscopyVibrational fingerprinting of layers
- 04AFM — Atomic Force MicroscopySurface topography and thickness
- 05SNOM — Scanning Near-field Optical MicroscopyOptical imaging beyond the diffraction limit
- 06Material CharacterizationStructural and optical analysis
Fabrication
02
- 07PhotolithographyPattern definition on substrates
- 08Micro/NanofabricationDevice-scale processing
This matrix lists research areas and the instruments used in that work. It is not a skill rating and carries no self-assigned score.
05 / SELECTED PUBLICATIONS
Research from the atomic scale to photonic devices
Graphene patterning without plasma etching via SU-8 pattern peel-off
A method for patterning graphene on a SiO₂/Si substrate using the adhesion of SU-8 and a peel-off process, without plasma etching.
View DOI (opens in a new tab) 10.1038/s41598-025-08895-2
Utilizing polarization-selective mode shaping by chalcogenide thin film to enhance the performance of graphene-based integrated optical devices
An investigation of polarization-dependent selective mode shaping using a chalcogenide thin film to improve the performance of graphene-based integrated optical devices.
View DOI (opens in a new tab) 10.1038/s41598-019-48890-y
Truncated pyramidal-shaped InAs/GaAs quantum dots in the presence of a vertical magnetic field: An investigation of THz wave emission and absorption
A theoretical study of truncated pyramidal InAs/GaAs quantum dots under a vertical magnetic field, focusing on transitions and on emission and absorption in the terahertz range.
View DOI (opens in a new tab) 10.1016/j.physe.2017.02.008
The complete, up-to-date publication list is available on Google Scholar.
View on Google Scholar (opens in a new tab)06 / ABOUT THE RESEARCHER
About the researcher
Dr. Maryam Riyahi دکتر مریم ریاحی
- Graphene Photonics Researcher
- 2D Material Integrated Photonics
Dr. Maryam Riyahi is a researcher working across graphene, photonics, and two-dimensional materials. Her research focuses on the fabrication, patterning, characterization, and integration of low-dimensional materials into optical systems and emerging technologies.
07 / CONTACT
A conversation can begin with one layer.
Get in touch for research discussions, scientific collaboration, and exchanging ideas about graphene and two-dimensional materials.