ADSORPTION OF HYDROGEN ON β-Ga2O3(100): A THEORETICAL STUDY

We have modeled the (100) surface of β-Ga2O3 with a clear-cut optimization from ab initio calculations. The adsorption geometry of one hydrogen atom on this surface was determined by a semi-empirical quantum chemistry method. H is found bonded to a tetrahedral Ga atom and no bond with surface oxygen atoms is detected. As a consequence of this Ga–H bond, the Ga–O overlap population decreases. This result is in good agreement with the recent spectroscopic determination of Ga–H IR frequencies on supported catalysts. The orbital composition of the Ga–H bond and density of states of tetrahedral and octahedral gallium ions, Ga(I), Ga(II), and that of oxygen before and after H adsorption are also addressed.

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