Site-dependent vibrationally assisted sticking effect on H 2-Si(001)2 × 2 surface interactions

• Main Authors: Arboleda, Nelson B., Jr., Kasai, Hideaki, Diño, Wilson Agerico, Nakanishi, Hiroshi
• Format: text
• Published: Animo Repository 2005
• Subjects: Adsorption; Curvature; Quantum theory; Dimers; Physics
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/1356; https://animorepository.dlsu.edu.ph/context/faculty_research/article/2355/type/native/viewcontent
• Institution: De La Salle University

We performed quantum dynamics calculations using available potential energy surfaces for the dissociative adsorption of H2 incident on a Si(001)2 × 2 surface. In this study, we show that the probability of adsorption for H2 and the effect of vibrationally assisted sticking (VAS) vary at different sites along the Si-dimer bond. Based on the sticking probability plots for H2 as functions of its initial translational energy, we show that the H2-silicon surface interactions are all activated, with the lowest potential barrier being found in the case of H 2 coming down the Si surface with its center of mass roughly above the down Si-dimer atom. On the other hand, the VAS effect is strongest when H2, while coming down the silicon surface along the surface normal, approaches the point farthest from the up Si-dimer atom along the Si-dimer bond. Here, the potential barrier is closest to the curved region along the reaction path in the corresponding potential energy surface for this system. © 2005 The Japan Society of Applied Physics.