Triphenylene adsorption on Cu(111) and relevant graphene self-assembly

Investigations on adsorption behavior of triphenylene (TP) and subsequent graphene self-assembly on Cu(111) were carried out mainly by using scanning tunneling microscopy (STM). At monolayer coverage, TP molecules formed a long-range ordered adsorption structure on Cu(111) with an uniform orientation. Graphene self-assembly on the Cu(111) substrate with TP molecules as precursor was achieved by annealing the sample, and a large-scale graphene overlayer was successfully captured after the sample annealing up to 1000 K. Three different Moire patterns generated from relative rotational disorders between the graphene overlayer and the Cu(111) substrate were observed, one with 4 degrees rotation between the graphene overlayer and the Cu(111) substrate with a periodicity of 2.93 nm, another with 7 degrees rotation and 2.15 nm of the size of the Moire supercell, and the third with 10 degrees rotation with a periodicity of 1.35 nm.