Achieving Flat Gold Surfaces for the Organization of Organic Molecules

Organic electronics are interesting for use in electronic devices but suffer in competition with inorganics due to their lower conductivity. Crystallizing organic semiconductors can increase their conductivities and a possible crystallization method is self-assembly driven by the topography and chemistry of an atomic surface reconstruction. This work aims to develop an atomically smooth Au(111) surface, which has a herring bone reconstruction. Many methods are known for samples in UHV, however these methods do not work in atmosphere or a glove box, such as is used in our lab. This work expands upon that of Maver et al. using torch annealing, which allows the atoms to rearrange into a lower energy state. We anneal the sample at 710±10°C for two minutes, and then three minutes at 410±10°C. This yields larger and flatter terraces compared to the unannealed material. The unannealed gold had mounds with no flat areas and a max depth of 7.6 nm. The annealed Au(111) had flat terraces, 13-30 nm in size, with step heights in the order of .235 nm, which matches the interplanar spacing for Au(111). In the future, we will optimize this process to achieve large terraces by adjusting the temperatures and times used.