Optical constants of amorphous germanium monochalcogenides

The dispersion of the optical constants ei and e2 was determined in the 0−e eV interval from the measured reflectivity on thin films of a-GeCh. Despite the certain nonstoichiometry, the results obtained on sulphide agree well with those of another form of a-GeS [19]. A close similarity between the sulphide and selenide was observed. The data on the telluride have a rather qualitative value only.