OPTOELECTRONIC AND STRUCTURAL-PROPERTIES OF A-GE1-XCX-H PREPARED BY RF REACTIVE COSPUTTERING

Optoelectronic, structural, and mechanical properties of hydrogenated amorphous germanium carbon (a-Ge1-xCx:H) alloys are presented. The fil ms were prepared by the rf cosputtering technique using graphite-germa nium composite targets. Films with carbon contents in the 0<x <1 range were prepared under the same conditions used to obtain a-Ge:H films w ith good optoelectronic properties. The trends of the optical gap, inf rared absorption, dark conductivity, and mechanical stress as a functi on of the carbon content suggest that the properties of films with low carbon concentration are mainly controlled by the incorporation of sp (3) hybridized carbon. These films have good optoelectronic and struct ural properties. As the carbon content increases, the properties of th e films are determined by the concentration of sp(2) carbon sites. (C) 1998 American Institute of Physics.