Preparation and properties of hydrogenated amorphous germanium nitride a-GeN{sub x}:H

The properties of a-GeN{sub x}:H films have been studied including the effects of oxygen and carbon impurities. The contamination of a-GeN{sub x}:H with oxygen and carbon is expressed as a-GeN{sub x}(O{sub y}C{sub z}):H, where x = n/Ge, y = O/Ge and z = C/Ge. The characteristics of a-GeN{sub x}(O{sub y}C{sub z}):H are summarized as follows: the sample is transparent at the center of a film, and the color of a film varies to light yellow and to brown at the outer edge depending on the magnetic field of the magnetron sputtering. The compositional ratios of the film vary from x = 0.34 to 0.28, y = 0.15 to 0.25 and z = 0.05 to 0.02 at the center and at outer edge of a film, respectively. Optical gap energy E{sub O5}, obtained by the photon energy at optical absorption coefficient of 5 x 10{sup 3} cm{sup {minus}1}, are 2.9 eV at the center and 1.7 eV at the outer edge of a film. E{sub O5} increases with the nitrogen content x in a-GeN{sub x}(O{sub y}C{sub z}):H but is independent of the content of oxygen and carbon.