Graphene STEM Imaging
Graphene is a hot topic nowadays. It even won the 2010 Nobel Prize in Physics. However, it wasn’t long ago (2003) that graphene was first experimentally realized. Graphene is interesting because it is a single atomic layer thick and has astounding material properties.
In 2008, when I worked on graphene at Cornell University in Professor Emeritus John Silcox’s electron microscopy group, a single sheet of graphene had yet to be directly imaged in a high resolution electron microscope. I was tasked with 1) developing a process to deposit graphene on a scanning transmission electron microscope (STEM) sample holder/grid and 2) attempt to image the graphene in a state-of-the-are Nion UltraSTEM.
Transferring the graphene from a silicon wafer to a TEM grid was no easy task. We did, however, manage the transfer process and we (likely) imaged the graphene lattice. However, we were beat to the punch by another group. Today, the transfer method of graphene to a different substrate is still difficult, but it has been made much easier by CVD grown graphene processes.
Nanofabrication & Process Development
Exfoliation Method Optimization
Wafer Resist Spin Coating
S/TEM Sample Preparation
Cornell University, Applied & Engineering Physics
Prof. Emeritus John Silcox
Dr. Sara Maccagnano-Zacher
Prof. Andre Mkhoyan, University of Minnesota