INFRARED-ABSORPTION IN HYDROGENATED AMORPHOUS AND CRYSTALLIZED GERMANIUM

The infrared spectrum of hydrogenated a-Ge produced by sputtering in an ArH2 mixture is reported. Bond stretching, bending, and wagging bands are observed. From the integrated absorption of these bands the concentration of GeH and GeH2 bonds is determined. We also report annealing experiments at temperatures below and above that required for crystallization, the amount of this crystallization being determined by Raman scattering. The GeH2 bands disappear upon annealing faster than GeH and virtually none are left in the crystallized material which nevertheless still contains a significant proportion of GeH bonds. The possible structure of the GeH bonds in the crystalline phase is discussed. © 1979.