Exfoliation and Lithography
MICROMECHANICAL EXFOLIATION
We use micromechanical exfoliation for synthesis of graphene as well as other 2D crystals (BN, MICA). We have several years of experience with micromechanical exfoliation. Our typical graphene (single layer) samples are several tens of micrometers long, with some samples being over several hundred micrometers long. Our samples are pristine, this we confirm by Raman and AFM measurements (see: Specrtoscopy link, SPM link).
We have existing collaboration with many research groups that use our samples for their experiments, and we are always open for new collaborations.
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Schematic representation of the exfoliation process |
Microscope images of graphene flakes (single-, bi- and tri-layer samples). |
UV PHOTOLITHOGRAPHY
Using a spin-coater, Karl Suss MJB3 mask aligner and a home built PVD system (more details in: equipment link) we are capable of making several contact geometries (usually in a two or four point probe configuration) as well as patterning
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Microscope image of a graphene sample with gold contacts in a four point probe configuration |
AFM image of the same sample, confirming no contamination from the lithography process |
Pattern for etching graphene into ribbons (microscope image viewed through photoresist) |
We measure sample resistivity in a DC mode and in a back-gate configuration. Samples are either in Ar environment, or encapsulated with pmma or made on HMDS treated substrates.
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Microscope image of a graphene sample with gold contacts in a four point probe configuration |
AFM image of the same sample, confirming no contamination from the lithography process |
Pattern for etching graphene into ribbons (microscope image viewed through photoresist) |
References:
Enhanced structural stability of DNA origami nanostructures by graphene encapsulation,
Matković, A., Vasić, B., Pesić, J., Prinz, J., Bald, I., Milosavljević, A.R., Gajić, R.,
New Journal of Physics, 18 (2), art. no. 025016 (2016) DOI: 10.1088/1367-2630/18/2/025016
