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 mu m 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 (T-g) of CdS-PET and ZnS-PET films have been found to be 118.3 degrees C and 117.4 degrees C respectively whereas T-g of commercial PET film is 89.7 degrees 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.