Characterization of silver photodiffusion in Ge8Sb2Te11 thin films

Silver-doped amorphous Ge8Sb2Te11 thin films have been prepared by photodiffusion at room-temperature; the Ge8Sb2Te11/Ag bilayer was deposited by vacuum thermal evaporation. Photodiffusion of Ag into the amorphous Ge8Sb2Te11 thin films has been carried out by illuminating the prepared Ge8Sb2Te11/Ag bilayer with halogen lamp. The photodiffused silver depth profile was traced by means of time of flight secondary ion mass spectroscopy. The film remains amorphous after Ag photodiffusion. The crystallization temperature of the films was evaluated by temperature dependent sheet resistance measurement. The amorphous nature and crystalline phases of the films have been identified by using X-ray diffraction.