Tuning of silicene-substrate interactions with potassium adsorption

The evolution of the electronic structure and the structural stability of epitaxial silicene on ZrB2(0001) thin films exposed to K atoms has been studied by angle-resolved photoelectron spectroscopy and low-energy electron diffraction. Potassium adsorption leads to charge donation to the silicene lattice, which is accompanied by the partial filling of a formerly unoccupied pi* band and by the increasing hybridization between the diboride surface state and the lower branch of the back-folded pi band. The results allow an identification of silicene-derived pi electronic states and confirm that before K adsorption, the interactions at the silicene-substrate interface are rather weak. (C) 2013 AIP Publishing LLC.