In 1995 Stephan was a visiting scientist at DuPont's Central Research and Development Laboratory in Wilmington, DE. Stephan Joined NIST in 1996 as a Research Chemist. His research focuses on the development of nanoscale probes of surface physiochemical properties. He has published numerous papers on the subject and has been awarded sixteen patents associated with microscopies for chemical and electrical characterization.
Stephan's awards include the American Chemical Society's Nobel Laureate Signature Award, the American Chemical Society's Procter & Gamble Award in Physical Chemistry, the American Chemical Society's Arthur F. Findeis Award for Achievement by a Young Analytical Scientist, a BF Goodrich Inventors Award, the Union Carbide Kenan Analytical Award, the Xerox President's Award in Materials Research, the Samuel Wesley Stratton Award for Excellence in Science and Engineering, the Department of Commerce Bronze Medal Award for Superior Federal Service, the Arthur S. Flemming Award for Outstanding Federal Service in Basic Science, American Chemical Society’s 100 New Voices in Chemistry, Chemical Science and Technology Lab Technical Achievement Award, ACS & GDCh Symposium on the Frontiers of Chemistry: Top 40 under 40, Ithaca College Outstanding Young Alumni Award, and the Kern Eighth Annual Graduate Research Exhibition, First Prize in Physical Sciences. Stephan was a Shell Foundation Doctoral Fellow, a Sigma Xi Graduate Fellow, and a Wheeler P. Davey Memorial Graduate Fellow.