摘要：

In this seminar we will discuss some of our results on the formation of graphene by sublimation and chemical vapor deposition on SiC and Sapphire substrates.  We will also discuss our work in the formation and characterization of few layer graphene clamped membranes suspended above SiC substrates.

We have demonstrated a technique for producing free-standing graphene on SiC using a photo-electrochemical (PEC) etch process and characterized the resulting nanomechanical graphene resonators. We extend this work to enable electron transport studies of suspended epitaxial graphene (SEG) on SiC. Graphene thickness was estimated to be ~1.3 monolayers using X-ray photoelectron spectroscopy. Graphene was photolithographically patterned using an oxygen plasma and then the devices were exposed to the PEC etch. A critical point drying method was used to dry the suspended devices.

报告人简短简历：

Michael G. Spencer was born in Detroit, MI, and raised in Washington DC. He received the B.S., M.Eng., and Ph.D. degrees from Cornell University, Ithaca, NY, in 1974, 1975, and 1981, respectively. He is presently a Professor of engineering at Cornell University.  He has more than 30 years of research experience in the epitaxial and bulk growth of compound semiconductors, such as GaAs, SiC, and AlN and more recently graphene (growth techniques include molecular beam epitaxy, vapor phase epitaxy, liquid phase epitaxy, and sublimation), microwave devices, solar cells, and electronic materials characterization techniques (including deep level transient spectroscopy, scanning probe spectroscopy and photoluminescence). His particular interest has been in the correlation of device performance with material growth and processing parameters. Recent work has emphasized graphene and wide band-gap materials. He taught for 18 years in the Engineering School of Howard University, Washington, D.C., a historically black college. He has authored more than 130 publications in the area of compound semiconductor research and has coauthored five U.S. patents with several patents pending. Dr. Spencer is a co-founder of the start-up company Widetronix (which is developing nuclear batteries made from SiC). Dr. Spencer was one the first organizers of the International Conference on SiC and Related Materials (ISCRM).  Dr. Spencer is currently a member of Army Research Laboratory Technical Assessment Board (administered by The National Academies).  Dr. Spencer is a recipient of the Presidential Young Investigator Award for1985. He has participated as a member and advisor of the National Society of Black Engineers (NSBE).