J. Phys. Chem. 1996, 100, 20015-20020
20015
Infrared Study of the Reactions of Atomic Deuterium with Amorphous Silicon Monohydride Szetsen S. Lee, Maynard J. Kong, and Stacey F. Bent* Department of Chemistry, New York UniVersity, New York, New York 10003
Chao-Ming Chiang and S. M. Gates IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 ReceiVed: July 1, 1996; In Final Form: October 3, 1996X
Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) has been applied to characterize amorphous silicon monohydride films before and after reaction with deuterium atoms. The hydride films were grown by chemical vapor deposition on oxide-covered silicon substrates, and the data suggest that the film is terminated by a homogeneous monolayer of primarily dimerized silicon monohydride. Exposure of this film to atomic deuterium causes the replacement of silicon hydride with adsorbed deuterium. Only the monodeuteride is formed by reaction at 200 °C. Reaction at -110 °C produces mono-, di-, and trideuteride, demonstrating that the isolation of insertion products is temperature-dependent.
I. Introduction The technological challenge of developing high-performance silicon-based photovoltaic devices has prompted studies of the chemical and physical properties of hydrogenated amorphous silicon (a-Si:H), which is an amorphous semiconductor that can be deposited inexpensively over large areas.1 The physical and optical properties of a-Si:H depend strongly on the hydrogen content and the microstructure of the material.1 In turn, the hydrogen content is defined by the method of preparation. One common method of growth is low-temperature (
