Laser-induced local profile transformation of multilayered graphene on a substrate

• Multi-layered graphene on Si/SiO2 was irradiated by series of nanosecond laser pulses.
• ~1 nm deep craters in graphene sheet were formed at laser fluence ~0.04 J/cm2.
• The number of graphene layers after ~0.04 J/cm2 irradiation remains the same.
• Microholes in graphene sheet were formed at higher fluences.
• Possible transformation mechanisms are discussed.

Multi-layered graphene deposited on silicon wafer was irradiated in air by sequences of nanosecond laser pulses. It is shown that ultra-shallow craters (cavities) with depth of ~1 nm and microholes can be formed in graphene sheet on the substrate at laser fluence ~0.04 J/cm2 well below the experimentally known graphene ablation threshold ≥0.25 J/cm2. Influence of intensity and number of laser pulses on the depth and roughness of the cavities are described. We suggest that the observed effects are related to laser heating and boiling of the adsorbate at graphene-silicon interface.

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