Structure and nanomechanical properties of CdTe thin films

CdTe thin films were produced by vacuum evaporation on glass sheets at substrate temperatures of 100 K and 300 K. The structural properties of the CdTe thin films were investigated through X-ray diffraction (XRD) technique and scanning electron microscopy (SEM). The mechanical properties (hardness, modulus and coating adhesion) were measured by nanoindentation and scratching techniques. XRD studies showed that the crystallinity of CdTe films improved with increasing substrate temperature. The grain size increased with the increase of substrate temperature and clearly facetted morphology was observed. The indentation hardness and modulus of CdTe thin films decreased with increasing grain size. The hardness and modulus increased gradually with increasing indentation depth due to the substrate effect. The adhesion of the coating increased with decreasing grain size.