Revealing the hydrogenated structure of silicene- (√13×√13)R13.9° by tip-induced dehydrogenation

The application of voltage pulse in a scanning tunneling microscope has been demonstrated to induce dehydrogenation on hydrogenated silicene/Ag(111), recovering intact silicene phases. This manipulation provides us a method to build a relationship between various silicene phases and their hydrogenated structures. Combining with density-functional theory calculations, hydrogenation of silicene-(√13×√13)R13.9° is found to produce the same half silicane as hydrogenated silicene-(2√3×2√3)R30°. These two silicene phases are suggested to be the same monolayer silicene on Ag(111), albeit with different Si buckling configurations and lattice strains. Our study not only reveals the hydrogenated structure of silicene-(√13×√13)R13.9°, but also offers significant potential for lithography and modification of hydrogenated silicene at atomic scale for future design of silicene-based electronic devices.