MICROSCOPY & IMAGING


software allows for real-time visualisation of modulus, adhesion force, etc. On graphene, adhesion force and modulus showed a contrast between the underlying sapphire terraces, the steps and graphene wrinkles (Fig. 3). Compared to the terraces, the elevations around the steps exhibit a lower adhesion force and a higher modulus suggesting that the fi lm


FIG. 3. Adhesion force and modulus on graphene on a sapphire substrate acquired via Park Systems’ PinPoint mode and the corresponding surface potential imaged via sideband KPFM at the same measurement area


becomes harder at these positions. T e correlation of the nanomechanical properties with the surface potential and the sample topography indicates a possible connection of the material’s mechanical and electronic properties.


SUMMARY T e combination of diff erent AFM techniques including sideband KPFM and PinPoint mode available on Park Systems’ research AFMs allows a holistic and in-depth characterisation of 2D materials as demonstrated on a wafer- scale CVD-grown graphene on sapphire produced in an Aixtron CCS R&D


reactor. T e measurements showed a distinct correlation of the sample’s surface potential with the adhesion force and modulus indicating a connection of graphene’s electronic and mechanical properties. Characterising the highly localised mechanical and electronic properties of 2D materials enable a tailored development for future nanoelectronics applications.


Ilka M. Hermes is with Park Systems & Simonas Krotkus is with Aixtron. www.parksystems.com


flexible. Laser Engine for Neuroscience and Biophotonics*


Up to 7 wavelengths 405 nm - 785 nm


iChrome FLE • 2-fiber switch / splitter • All diode design for long lifetime • COOLAC


automatic alignment Plug & play installation!


*Convince yourself and apply for your own free live demo!


www.toptica.com/flexible www.scientistlive.com 49


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60