Thermo‐Mechanical Study of Chalcogenide (CdS, ZnS) Coated Polyethylene Terephthalate (PET) Films

Chalcogenide materials such as CdS/ZnS have been coated on polyethylene terephthalate (PET) films using vacuum thermal evaporation method. Commercial PET film of thickness 20 μm has been used as flexible substrate. The structure of PET and coated materials (CdS, ZnS) has been determined using X‐ray diffraction pattern (XRD). Thermo‐mechanical study of these films has been carried out using Dynamic Mechanical Analyser (DMA). The glass transition temperature (Tg) of CdS‐PET and ZnS‐PET films have been found to be 118.3°C and 117.4°C respectively whereas Tg of commercial PET film is 89.7°C. The stress‐strain curves of CdS (or ZnS)‐PET films at room temperature explain the mechanical response of these films under the applied load.