Desorption kinetics, hydrogen/silicon

Gupta, P., Colvin, V.L. and George, S.M. (1988) Hydrogen desorption kinetics from monohydride and dihydride species on silicon surfaces , Phys. Rev. B 37, 8234. 

In the 1970s and 1980s both the clean and H-covered Si surfaces were characterized by diffraction and spectroscopic methods, but only in the last decade have there been reproducible studies of chemical kinetics and dynamics on well-characterized silicon surfaces. Despite the conceptual simplicity of hydrogen as an adsorbate, this system has turned out to be rich and complex, revealing new principles of surface chemistry that are not typical of reactions on metal surfaces. For example, the desorption of hydrogen, in which two adsorbed H atoms recombine to form H2, is approximately first order in H coverage on the Si(lOO) surface. This result is unexpected for an elementary reaction between two atoms, and recombi-native desorption on metals is typically second order. The fact that first-order desorption kinetics has now been observed on a number of covalent surfaces demonstrates its broader significance. 

Ruano GD, Ferron J, Arce RD, Koropecki RR (2011) Kinetics of electron induced desorption of hydrogen in nanostmctured porous silicon. Phys Status Solidi (a) 208(6) 1453-1457 Salonen J, Laine E (1996) The quenching and recovery of photoluminescence in porous silicon. J Appl Phys 80(10) 5984-5985... 

In view of the many important applications in semiconductor technology, the interaction of hydrogen with silicon surfaces has been intensively studied. Recombinative H2 desorption from Si(100)-2 x 1 follows first-order kinetics89, unusual when compared with the second-order kinetics observed for H2 desorption from Si(lll)-7 x 7. The measured activation barriers for the desorption of H2 on Si(100) range from 45 to 66 kcalmol-189 90. 

Doren, D. J. (1996a). Kinetics and dynamics of hydrogen adsorption and desorption on silicon surfaces. 4<7v. Chem. Phys. 95, 1. 

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