Interactions between H and Pt were studied in n-type and p-type material by using deep-level transient spectroscopy. The H was introduced by wet chemical etching, or during crystal growth. In both cases, the H formed only electrically active complexes with Pt. Four Pt-H related deep levels were identified. These were designated as E(90) at Ec - 0.18eV, E(250) at Ec - 0.50eV, H(150) at Ev + 0.30eV, and H(210) at Ev + 0.40eV. These levels belonged to at least 3 different Pt-H complexes. Level E(250) was identical to the so-called mid-gap level, in Pt-doped Si, which was believed to control the minority carrier lifetime in Pt-doped material. Level H(150) was an acceptor, and was present in both n-type and p-type samples after hydrogenation. It was associated with a Pt-H complex which contained more H atoms than the complexes that were responsible for the other H-related levels. Annealing at temperatures above 600K resulted in complete dissociation of all the Pt-H related defects, and the substitutional Pt concentration was fully restored.

J.U.Sachse, E.O.Sveinbjörnsson, W.Jost, J.Weber, H.Lemke: Physical Review B, 1997, 55[24], 16176-85