Superstructures at Te/Au(111) interface evolving upon increasing Te coverage

By in-situ low temperature scanning tunneling microscopy, we systematically investigated the superstructure evolution at Te/Au(111) interface upon increasing Te coverage. Te atoms form one-dimensional 3R30∘ chains at ∼0.10 monolayer (ML) coverage. Two two-dimensional chiral superstructures, (111×111)R4.7∘ and (321×321)R10.9∘, are selectively formed with the Te coverage below and above 1/3 ML, respectively. The two chiral superstructures can be converted to each other reversibly by adding Te atoms or moderately annealing. A honeycomb-like superstructure, decorated with adatoms that are distributed in quasi-one-dimensional chains, is observed by further increasing the Te coverage to 4/9 ML. At the Te/Au(111) interface, an interfacial state at −0.65 eV to −0.55 eV below the Fermi level is also resolved by scanning tunneling spectroscopy. The formation of these Te-induced high-order superstructures is accompanied by relaxation of gold atoms in the surface layer, indicating a strong Te–Au interaction. Our work demonstrates a reliable method to fabricate Te nanostructures on noble metals in a controlled way.