Buckled Silicene Formation on Ir(111)

Abstract

Silicene, a two-dimensional (2D) honeycomb structure similar to graphene, has been successfully fabricated on an Ir(111) substrate. It is characterized as a (√7×√7) superstructure with respect to the substrate lattice, as revealed by low energy electron diffraction and scanning tunneling microscopy. Such a superstructure coincides with the (√3×√3) superlattice of silicene. First-principles calculations confirm that this is a (√3×√3)silicene/(√7×√7)Ir(111) configuration and that it has a buckled conformation. Importantly, the calculated electron localization function shows that the silicon adlayer on the Ir(111) substrate has 2D continuity. This work provides a method to fabricate high-quality silicene and an explanation for the formation of the buckled silicene sheet.

Prediction of Silicon-Based Layered Structures for Optoelectronic Applications

“…In the same time, singer-layer silicene itself is unstable. It must be grown on metallic substates 22,23 and can not be exfoliated from substrates. Furthermore, substrates change the electronic properties of silicene.…”

π conjugation in the epitaxial Si(111)- 3×3 surface: Unconventional “bamboo hat” bonding geometry for Si

“…The ( √ 3× √ 3) superstructure therefore represents a new surface reconstruction in the Si(111) surface, differing from (7×7) and (2×1) surface reconstruction of bulk-terminated Si. We note that there is also a monolayer ( √ 3× √ 3) silicene reported on the Ag and Ir substrate [12,13], which is controlled by the substrate induced strain [36]. Although it does serve as the buffer layer for the subsequent ( √ 3× √ 3) reconstructed layers [20,21], its formation is clearly different.…”

“…Weak π-conjugation has been found in Si(111)-(2×1) surface within a linear chain structure [6][7][8], but the most typical hexagonal ring structure has never been seen. This underlies the difficulty in experimentally synthesizing the elusive freestanding form of silicene [9][10][11][12][13][14].…”

Predicted Siliconoids by Bridging Si9 Clusters through sp3-Si Linkers

“…It is reported as a buckled sheet of sp 3 /sp 2 -hybridized Si atoms connected to wrinkled six membered rings, which is stabilized through intrinsic van-der-Waals interactions [25]. Silicene is experimentally accessible only on metal surfaces [26][27][28]. Theoretical investigations on this material are reviewed in several articles [29][30][31].…”