It was noted that the wet chemical etching of Pd-doped material introduced at least 7 new levels into the band-gap. The depth profiles of the levels linked them to 3 different Pd-H complexes. An analysis of the profiles permitted the levels to be related to complexes with one, two or three H atoms. Evidence for the complete passivation of substitutional Pd was provided by a complex which contained at least four H atoms.

Depth Profiles of Palladium-Hydrogen Complexes in Silicon J.Weber, S.Knack, J.U.Sachse: Physica B, 1999, 273-274, 429-32