The most feasible method for the preparation of chalcogenide thin films is RF Sputtering Technique. Although PLD (Pulsed Laser deposition) technique will also work for the same if appropriately used.
The important aspect of film preparation in case of multicomponent glasses is to maintain same composition in film as in bulk. Ordinary thermal evaporation may lead to fractational effect. However, flash evaporation may be used to get films without fractational effects. One has to check the composition after film preparation. If this technique does not work, one can go sophisticated techniques like R.F. sputtering or pulse laser deposition to avoid fractational effect.