Every unit ships with a serialised Certificate of Analysis: optical coverage, a Raman peak table, and adlayer and wrinkle statistics measured on your batch rather than a representative lot.
Reading your Certificate of Analysis
The CoA is serialised to the batch you received. Four things on it are worth understanding before you plan an experiment around the material.
- Optical coverage. The percentage of the surveyed area carrying continuous monolayer. Specified at 95% minimum; your certificate carries the measured figure.
- Raman peak table. The G and 2D peak positions and their intensity ratio identify the film as monolayer. The D peak is the defect indicator — the smaller it is relative to G, the cleaner the lattice.
- Adlayer statistics. Small patches of second-layer growth. Harmless for many uses, but they matter for uniform-thickness work such as optical stacks and gate dielectrics.
- Wrinkle statistics. Folds formed as the film relaxes onto its substrate. Relevant where you need continuous conduction across a long channel.
Batch-specific datasheets can be tailored on request. If you need a parameter reported that is not on the standard certificate, ask before the batch is run rather than after.
Handling and transfer
Most material that arrives damaged was damaged after it arrived. A monolayer is one atom thick; it is unforgiving of things that would not trouble any other material in your lab.
- Receiving. Inspect in the packaging before removing anything. Graphene on copper is supplied interleaved — keep it that way until the moment of use.
- Storage. Dry, at room temperature, flat, in the original packaging. Copper oxidises; humidity and time both degrade the surface you are going to transfer from.
- Handling. Clean tweezers at the foil edge only. Never touch the growth face. Do not slide sheets against one another.
- Transfer. Whether you use a polymer support and etch, or an electrochemical or mechanical lift-off, the failure modes are the same: trapped water, trapped polymer, and stress at the moment of release. Go slowly at release.
- After transfer. Residual polymer is the most common cause of disappointing electrical results. Confirm removal by Raman before concluding the film is at fault.
We transfer to a customer-supplied substrate as a service, up to 8 inches. For difficult substrates that is usually the cheaper route than developing a transfer process of your own.
Technical reference
Monolayer graphene on copper
A continuous one-atom-thick layer of carbon, grown by chemical vapour deposition onto 25-micron copper foil. Copper is used as the growth substrate because its low carbon solubility and weak catalytic activity favour a single layer rather than a stack — the film self-limits at one atom.
The working form for electrodes, sensors and transferred device layers. Supplied as-grown on the foil, or transferred to your substrate.
Monolayer hexagonal boron nitride
Boron and nitrogen atoms covalently bound in a hexagonal lattice — graphene’s structural twin, with the opposite electrical character. A wide band gap near 5.9 eV makes hBN as good an insulator as graphene is a conductor, and it carries one of the highest thermal conductivities of any electrical insulator available.
Transparent to visible light and to radio frequencies, refractory and flame retardant, with useful lubricity and wear resistance. Used as a gate dielectric, as an encapsulation layer, and as a thermal interface material.
Graphene on hBN heterostructures
The lattice constants of graphene and hBN match closely enough that hBN makes a near-ideal substrate for graphene. Graphene laid on hBN rather than on silicon dioxide sees a far smoother, charge-trap-free surface, and electron mobility rises substantially as a result.
This is the standard construction for van der Waals heterostructures, including stacks with WSe₂, MoSe₂ and other 2D semiconductors. Available in configurations up to 8 inches.
Standards and milestones
Material sold as “graphene” varies enormously in what it actually is, and inconsistent terminology has held back commercialisation across the whole industry. The first ISO standard for graphene terminology was published in 2017 with input from experts in 37 countries; Grolltex has participated in the US standards conversation since 2018, including the industry discussions taken to Congress that year, and follows nanotechnology standards work under ANSI and ISO/TC 229.
- Manufacturing since 2017 — over 500 orders shipped to customers in 28 countries.
- Patented transfer process — metal-assisted exfoliation, enabling copper reuse.
- US patent for ultra-sensitive graphene strain sensors, built on the same monolayer material sold here.
- hBN manufacturing since 2018 — among the first commercial sources of single-layer hexagonal boron nitride in North America.
- Production-line delivery — Grolltex has designed, built and installed a complete graphene and hBN synthesis and wet-transfer line for a Fortune 500 customer’s own 200 mm facility in 2026.
Something not answered here
Technical questions go to support@grolltex.com and are answered by someone who has run the process. For custom sizes, substrates, volumes or a specification you do not see, send a quote request.