Ab initio study for Si-H bond vibration on the surface of silicon vacancy

Si-H bond vibrational frequency on the surface of silicon multivacancies and platelets is estimated by the ab initio molecular dynamics method. There are two forms of hydrogen molecules considered whose vibrational frequencies agree with the experimental ones, one is in silicon multivacancies and the other is in silicon platelets which are planar vacancies. In this work, we identify that the experimental peak frequency is due to hydrogen molecules in platelets, from the information of Si-H bond vibrational frequency, particularly its difference in broadness that is also observed in the experiment.