Silicon dihydride desorption

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. 

Gupta et al. [20] took time-dependent infrared spectra simultaneously with desorption rate measurements on porous silicon. They showed that the low temperature ( 2) desorption peak removes the dihydride, while the high temperature (/Sj) peak corresponds to desorption from the monohydride state. This means that a pure monohydiide state can be established by exposing the surface to atomic H, then annealing to about 630 K, a temperature high enough to desorb the dihydride but not the monohydiide. Porous silicon was... 

Gupta et al. [20] found second-order kinetics for desorption from the dihydride phase on porous silicon. The corresponding activation energy from isothermal measurements is 43 kcal/mol. The TPD experiments of Flowers et al. [40] on Si(100)-2 X 1 also showed that desorption from the dihydride was second order, with an activation energy of 47 kcal/mol. This result is derived from a model that estimates the equilibrium density of dihydrides as a function of coverage and temperature. This model has been criticized... 

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