Study of CdS Thin Film’s Structural, Morphological, and Mechanical Properties

In this study the structural, morphological and mechanical properties of the vacuum evaporated CdS thin film’s properties were investigated. The Si substrate was employed to grow the CdS thin film using the vacuum evaporation technique. The X-ray analysis revealed a polycrystalline hexagonal phase along the (002) preferential plane. From the X-ray results, the obtained crystalline parameters, such as the average crystallite size, microstrains, and dislocation density, were 14.5 nm, 10.8, and 4.70 × 1011 lines/cm2, respectively. The scanning electron microscopy (SEM) images indicated a uniform, continuous, and crack-free film of grain size 20–40 nm. The energy dispersive spectroscopy (EDS) analysis confirmed the pure and good stoichiometric film. The ellipsometry analysis indicated a refractive index of 2.43–2.45 of the CdS film and reconfirmed the film thickness 190–200 nm. The film was measured for roughness and found to be uniform, smooth, and compact with a 0.16 nm (rms) roughness. Nano-indentation was used to evaluate the CdS film’s hardness and Young’s modulus. The fine adhesion of the CdS film was tested with scotch tape. Thus, CdS film’s good structural, morphological, and mechanical properties make it a suitable transparent window layer in solar cells and other microelectronic devices.