The mid-gap level in Pt-doped n-type material, which was thought to be the predominant recombination center, was found to be a Pt-H complex. After hydrogenation by means of wet chemical etching at room temperature, the level was observed only in material close to the surface. It annealed out at temperatures above 600K. The defect profiles which were determined by means of deep-level transient spectroscopy clearly related this level to the concentration profile of atomic H.

J.U.Sachse, E.O.Sveinbjörnsson, W.Jost, J.Weber, H.Lemke: Applied Physics Letters, 1997, 70[12], 1584-6