title: Non-adiabatic ab initio molecular dynamics of supersonic beam epitaxy of silicon carbide at room temperature.
abstract: In this work, we investigate the processes leading to the room-temperature growth of silicon carbide thin films by supersonic molecular beam epitaxy technique. We present experimental data showing that the collision of fullerene on a silicon surface induces strong chemical-physical perturbations and, for sufficient velocity, disruption of molecular bonds, and cage breaking with formation of nanostructures with different stoichiometric character. We show that in these out-of-equilibrium conditions, it is necessary to go beyond the standard implementations of density functional theory, as ab initio methods based on the Born-Oppenheimer approximation fail to capture the excited-state dynamics. In particular, we analyse the Si-C(60) collision within the non-adiabatic nuclear dynamics framework, where stochastic hops occur between adiabatic surfaces calculated with time-dependent density functional theory. This theoretical description of the C(60) impact on the Si surface is in good agreement with our experimental findings.
authors: Interdisciplinary Laboratory for Computational Science, FBK-Center for Materials and Microsystems and University of Trento, Trento, Italy. taioli@fbk.eu
authors: Simone
authors: S
authors: Taioli
authors: Giovanni
authors: G
authors: Garberoglio
authors: Stefano
authors: S
authors: Simonucci
authors: Silvio
authors: S
authors: a Beccara
authors: Lucrezia
authors: L
authors: Aversa
authors: Marco
authors: M
authors: Nardi
authors: Roberto
authors: R
authors: Verucchi
authors: Salvatore
authors: S
authors: Iannotta
authors: Maurizio
authors: M
authors: Dapor
authors: Dario
authors: D
authors: Alfè
mesh_terms: D017554:Carbon Compounds, Inorganic / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D011789:Quantum Theory; D017655:Silicon Compounds / Q000737:chemistry*; D013696:Temperature
chemical_list: D017554:Carbon Compounds, Inorganic; D017655:Silicon Compounds; C022088:silicon carbide