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Theory of adsorption and desorption of H_2/Si(001)

E. Pehlke·M. Scheffler
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Abstract

While the small sticking coefficient for molecular hydrogen on the Si(001) surface apparently requires a large energy barrier of adsorption, no such barrier is observed in desorption experiments. We have calculated the potential-energy surface of an H_2 molecule in front of a Si(001) surface. If we relax the Si substrate, we find an optimum desorption path with a low (\lesssim 0.3 eV) adsorption energy barrier. While molecules impinging on the surface will mostly be reflected at the larger barrier of some frozen-substrate, molecules adsorbed on the surface can desorb along the low-barrier path.

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E. Pehlke, M. Scheffler. 1994-12-08. Theory of adsorption and desorption of H_2/Si(001). https://doi.org/10.1103/physrevlett.74.952

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