Optimization of the Generation of Graphene via Hydrogen - PowerPoint PPT Presentation

Optimization of the Generation of Graphene via Hydrogen Intercalation Determining the Best T emperature and Time for Making Graphene by Separating the Buffer Layer from the Silicon Carbide Substrate Malynda L. Wood Southwest DeKalb High School Dr. Edward Conrad July 25, 2014

Problem  Prior samples intercalated at1100 o C damaged  Needed best temperature and time to get undamaged samples

Graphene  Two dimensional structure  One atom thick  Strong  Conductive "Graphen" by AlexanderAlUS - Own work. Licensed under Creative Commons Attribution-Share Alike 3.0

Buffer Layer  Buffer layer between substrate and graphene on silicon face  Buffer layer is structurally similar to graphene that is covalently bonded to the substrate  Hydrogen intercalation can break the covalent bonds between silicon and the buffer layer  Converts the buffer layer to quasi-free- standing graphene

Research Objective  Determine optimum method of obtaining graphene through hydrogen intercalation by ◦ Determining optimum temperature ◦ Determining optimum time

Methodology  Intercalation process ◦ First Nano Graphene Furnace ◦ 600 torr H 2 ◦ H 2 99.999% purity ◦ 900 sccm flow rate

Methodology  Samples intercalated for 2 hours at : ◦ 700 C ◦ 800 C ◦ 900 C ◦ 950 C ◦ 1000 C

Methodology ◦ Samples intercalated for 3 hours at:  700 C  900 C ◦ Sample intercalated for 10 min at  900 C ◦ All samples evaluated by Raman Spectroscopy

700 C 800 C 900 C 950 C 1000 C

Findings  Of the temperatures tested 900 C provided the best results  Of the times tested 10 minutes produced the best results

Next Steps  Further experiments on finding the best time  Determining if these times and temperatures also apply to etched samples and nanoribbons

Lesson Plan  Resistance ◦ Conductors vs Insulators ◦ Factors affecting resistance  Resistance on a wire simulations  Resistance on a wire lab  Research paper on Graphene

I thankfully acknowledge the following for their invaluable assistance  National Science Foundation Grant (DMR1005880)  Dr. Ed Conrad  Feng Wang  Matthew Conrad  Katie Jenkins  Meredith Nevius  John Pham