Image of the Month

September 2016

Graphene on SiC, imaging and dI/dV mapping

Figure 1:  The sample is graphene grown on SiC by Joshua Robinson’s group at Penn State. The image is a large scale (50nm) high resolution (2048px) simultaneously collected dI/dV and topo image. Taken at 200mV and 0.1nA. dI/dV setting is 10mV excitation at 1kHz. The Moire pattern is clear in the main image, while the zoom shows atomic resolution.

Graphene grown on SiC is one of the most promising routes for producing large-scale graphene devices and heterostructures. Here we studied topography and variations in local density of states of graphene grown on SiC by Joshua Robinson’s group at Penn State.  This characterization of the base graphene growth is in preparation for developing work that aims to understand the local electronic states across graphene heterostructures. The figure shows a large scale image (50nm) taken at a high resolution (2048px) and a simultaneously collected dI/dV map (at 200mV and 0.1nA) from Shawna Hollen’s group at University of New Hampshire. The large scale image shows a superposition of a Moire pattern and electronic variations, while the zoom shows details down to atomic resolution.

Shruti Subramanian in Joshua Robinson’s group at Penn State grew the graphene on SiC samples. Jake Riffle in Shawna Hollen’s group at University of New Hampshire took the STM/STS data.

Credits:
Jake Riffle2, Shruti Subramanian1, Joshua Robinson1 and Shawna Hollen2

Department of Materials Science and Engineering and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, USA

University of New Hampshire, Department of Physics, 9 Library Way, Durham, NH 03824

Images and data graciously provided by Professor Shawna Hollen, University of New Hampshire, Durham, New Hampshire.

Microscope:
RHK PanScan Freedom STM/AFM

Control System:
RHK R9 Control System