Adsorption Kinetics of Hydrogen Sulfide and Thiols on GaAs (001) Surfaces in a Vacuum

• DOI: 10.1021/jp075968x
• Publication Date: 2008-02-20T10:00:48Z
• Authors: Oleksandr Voznyy; Jan J. Dubowski
• Keywords: Physisorption; Chemisorption; Dangling bond

Adsorption mechanisms of hydrogen sulfide and alkanethiols on GaAs (001) surfaces prepared in a vacuum were studied using first principles calculations. The need for physisorbed precursor was confirmed based energetic arguments molecular dynamics simulations the transition from physisorption to chemisorption state. preference S−Ga bond formation found, resulting weak non-dissociative state formed by overlap sulfur lone pair orbital with an empty Ga dangling bond. Physisorption energies height barrier found be very similar those gold, while main difference gold that remains surface upon S−H cleavage. Obtained results allowed more advanced interpretation experimental data concerning H2S thiol adsorption GaAs.