Atomic structure of the root 3 x root 3 phase of silicene on Ag(111)

作者：Cahangirov Seymur^*; Ozcelik Veli Ongun; Xian Lede; Avila Jose; Cho Suyeon; Asensio Maria C; Ciraci Salim; Rubio Angel

来源：Physical Review B, 2014, 90(3): 035448.

DOI：10.1103/PhysRevB.90.035448

The growth of the root 3 x root 3 reconstructed silicene on Ag substrate has been frequently observed in experiments while its atomic structure and formation mechanism is poorly understood. Here, by first-principles calculations, we show that root 3 x root 3 reconstructed silicene is constituted by dumbbell units of Si atoms arranged in a honeycomb pattern. Our model shows excellent agreement with the experimentally reported lattice constant and STM image. We propose a new mechanism for explaining the spontaneous and consequential formation of root 3 x root 3 structures from 3 x 3 structures on Ag substrate. We show that the root 3 x root 3 reconstruction is mainly determined by the interaction between Si atoms and have weak influence from Ag substrate. The proposed mechanism opens the path to understanding of multilayer silicon.

• 出版日期2014-7-28