Regensburg 2019 – wissenschaftliches Programm
O 66.11: Poster
Mittwoch, 3. April 2019, 17:45–20:00, Poster B2
Revealing the hydrogenated structure of silicene r13xr13 by STM tip induced dehydrogenation — •jinglan qiu — Hebei Normal University, Shijiazhuang, China
Although ordered and reversible hydrogenation has been demonstrated on silicene 4x4 and 2r3x2r3 superstructures, the hydrogenated structure of silicene r13xr13 (type I and type II) have not yet been revealed. Recently, we find that atomic hydrogen desorption processes can be induced by field-emitted or tunneling electrons from the STM tip, converting the hydrogen terminated silicene to intact monolayer silicene, including 4x4, 2r3x2r3 and r13xr13 phases. Bombardment of the surface with low energy (above 3eV) electrons desorbs the hydrogen and creates a bias dependent desorption area under the tip apex. From the high resolution STM images before and after hydrogen desorption, we get the one-to-one correspondence between hydrogenated silicene and various silicene phases. Interestingly, for silicene r13xr13 (type I), the hydrogenated structure appears almost identical to half-silicane that formed on silicene 2r3x2r3, indicating it an intact monolayer silicene as well. However, the hydrogenated structure of silicene r13xr13 (type II) shows quite differently with small pieces of silicene 1x1 surrounded by various size of black holes that expose the Ag(111) substrate. Thus, silicene r13xr13 (type II) should be regarded as a "precursor phase" for more ordered phases such as 4x4 and r13xr13.