Past studies on graphene show that scattering from disorder can give rise to weak Anderson localization, but a disorder-driven quantum metal-insulator transition has not been observed. Here we present simultaneous STM and electronic transport measurements of graphene devices decorated with gold adatoms using a low temperature scanning tunneling microscope (STM) on graphene field effect transistors. These data show drastic changes in the electronic landscape as well as quasiparticle scattering off defects on graphene on SiO2/Si. We study the microscopic scattering mechanisms, including the effects of charge puddles versus point-like disorder, and present methods of analyzing non-ideal defects with STM. These experiments are the first steps toward understanding the phase space near disorder-tuned metal-insulator quantum phase transitions in 2D materials.
