Hydrogen desorption from silicane and germanane crystals: Toward creation of free-standing monolayer silicene and germanene

We investigate hydrogen desorptions from monolayer and multilayer graphane analogs, namely, silicane (SiH) and germanane (GeH), by the first-principles calculations. It is found from the calculated pressure–temperature diagrams of the monolayer and multilayer SiH and GeH crystals that the hydrogen atoms can be removed by heating and reducing hydrogen partial pressure. We also perform thermal-desorption-spectroscopy measurements for the multilayer crystals in order to demonstrate the validity of the theoretical calculations, and it turns out that the theoretical results are worth believing. Our theoretical results for monolayer SiH/GeH crystals indicate monolayer SiH and GeH crystals possess high potential to find their application as a precursor to free-standing monolayer silicene and germanene, respectively.