Absorption edge measurements in tin disulphide thin films

Thin films of tin disulphide have been prepared by the reactive evaporation of the individual components. It has been found that a sulphur flux of 1.5*10 16 to 2.8*10 16 molecules cm -2 s -1 , a metal atom flux of 4*10 14 to 1.5*10 15 atoms cm -2 s -1 , and a substrate temperature in the range 295-335K gives good stoichiometric films. Optical absorption studies indicate that the fundamental absorption edge arises due to an allowed indirect transition at 2.12+or-0.02 eV. An indirect allowed transition at 2.31+or-0.02 eV, not reported earlier, has also been detected.