LAUSR

We have modified the set-up of a conventional scanning electron microscope (SEM) in order to enable the observation of catalyst surface dynamics under controlled atmosphere and temperature. Using this instrument, we perform in situ investigations on chemical vapor deposition (CVD) growth of graphene on different metal catalysts. Since the experiments are performed in the chamber of a microscope, it is possible to observe complete CVD processes starting from substrate annealing through graphene nucleation and growth and, finally, substrate cooling in real time at nanometer-scale resolution without the need of sample transfer. The nucleation and growth of single layer graphene can be investigated at temperatures of up to 1000°C, while at the same time, surface dynamics of the active metal catalyst can be studied. Growth on polycrystalline substrates reveals grain orientation dependent growth dynamics and catalytic activity [1]. Due to the high sensitivity of the secondary electron signal to changes in the work function and charge transfer at the surface, we are able to visualize different degrees of graphene-substrate coupling [2].