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Title: Electron-ion dynamics in laser-assisted desorption of hydrogen atoms from H-Si(111) surface

Abstract

In the framework of real time real space time-dependent density functional theory we have studied the electron-ion dynamics of a hydrogen-terminated silicon surface H-Si(111) subjected to intense laser irradiation. Two surface fragments of different sizes have been used in the simulations. When the intensity and duration of the laser exceed certain levels (which depend on the wavelength) we observe the desorption of the hydrogen atoms, while the underlying silicon layer remains essentially undamaged. Upon further increase of the laser intensity, the chemical bonds between silicon atoms break as well. The results of the simulations suggest that with an appropriate choice of laser parameters it should be possible to remove the hydrogen layer from the H-Si(111) surface in a matter of a few tens of femtoseconds. We have also observed that at high laser field intensities (2-4 V/A in this work) the desorption occurs even when the laser frequency is smaller than the optical gap of the silicon surface fragments. Therefore, nonlinear phenomena must play an essential role in such desorption processes.

Authors:
;  [1]
  1. Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States)
Publication Date:
OSTI Identifier:
22036730
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 110; Journal Issue: 6; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; CHEMICAL BONDS; CRYSTAL STRUCTURE; DENSITY FUNCTIONAL METHOD; DESORPTION; ELECTRONS; ENERGY GAP; HYDROGEN; IONS; LASER RADIATION; LAYERS; NONLINEAR PROBLEMS; SEMICONDUCTOR MATERIALS; SILICON; SURFACES; WAVELENGTHS

Citation Formats

Bubin, Sergiy, and Varga, Kalman. Electron-ion dynamics in laser-assisted desorption of hydrogen atoms from H-Si(111) surface. United States: N. p., 2011. Web. doi:10.1063/1.3638064.
Bubin, Sergiy, & Varga, Kalman. Electron-ion dynamics in laser-assisted desorption of hydrogen atoms from H-Si(111) surface. United States. doi:10.1063/1.3638064.
Bubin, Sergiy, and Varga, Kalman. Thu . "Electron-ion dynamics in laser-assisted desorption of hydrogen atoms from H-Si(111) surface". United States. doi:10.1063/1.3638064.
@article{osti_22036730,
title = {Electron-ion dynamics in laser-assisted desorption of hydrogen atoms from H-Si(111) surface},
author = {Bubin, Sergiy and Varga, Kalman},
abstractNote = {In the framework of real time real space time-dependent density functional theory we have studied the electron-ion dynamics of a hydrogen-terminated silicon surface H-Si(111) subjected to intense laser irradiation. Two surface fragments of different sizes have been used in the simulations. When the intensity and duration of the laser exceed certain levels (which depend on the wavelength) we observe the desorption of the hydrogen atoms, while the underlying silicon layer remains essentially undamaged. Upon further increase of the laser intensity, the chemical bonds between silicon atoms break as well. The results of the simulations suggest that with an appropriate choice of laser parameters it should be possible to remove the hydrogen layer from the H-Si(111) surface in a matter of a few tens of femtoseconds. We have also observed that at high laser field intensities (2-4 V/A in this work) the desorption occurs even when the laser frequency is smaller than the optical gap of the silicon surface fragments. Therefore, nonlinear phenomena must play an essential role in such desorption processes.},
doi = {10.1063/1.3638064},
journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 6,
volume = 110,
place = {United States},
year = {2011},
month = {9}
}