Chen Jian, Du Yi, Li Zhi, Li Wenbin, Feng Baojie, Qiu Jinlan, Cheng Peng, Xue Dou Shi, Chen Lan, Wu Kehui
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Institute for Superconducting and Electronic Materials (ISEM), University of Wollongong, Wollongong, NSW 2525, Australia.
Sci Rep. 2015 Aug 28;5:13590. doi: 10.1038/srep13590.
The "multilayer silicene" films were grown on Ag(111), with increasing thickness above 30 monolayers (ML). Scanning tunneling microscopy (STM) observations suggest that the "multilayer silicene" is indeed a bulk-like Si(111) film with a (√3 × √3)R30° honeycomb superstructure on surface. The possibility for formation of Si(111)(√3 × √3)R30°-Ag reconstruction on the surface can be distinctively ruled out by peeling off the surface layer with the STM tip. On this surface, delocalized surface state as well as linear energy-momentum dispersion was observed from quasiparticle interference patterns. Our results indicate that a bulklike silicon film with diamondlike structure can also host delocalized surface state, which is even more attractive for potential applications, such as new generation of nanodevices based on Si.
“多层硅烯”薄膜生长在Ag(111)上，厚度超过30个单层（ML）且不断增加。扫描隧道显微镜（STM）观察表明，“多层硅烯”实际上是一种块状的Si(111)薄膜，其表面具有(√3 × √3)R30°蜂窝状超结构。通过用STM针尖剥离表面层，可以明确排除在表面形成Si(111)(√3 × √3)R30°-Ag重构的可能性。在该表面上，从准粒子干涉图案中观察到了离域表面态以及线性能量-动量色散。我们的结果表明，具有类金刚石结构的块状硅薄膜也可以承载离域表面态，这对于潜在应用，如基于硅的新一代纳米器件，更具吸引力。
