Abstract:
In this thesis, (CdS)₁₋ₓ (ZnTe)ₓ (0≤x≤1) and CuSbS2 thin films were deposited on slide glass substrate by vacuum thermal evaporation method. The sets of CdS, ZnTe and Cu₂S, Sb₂S₃ powders with high purity grade were used as the precursors for the first kind and for the second kind of desired films, respectively. The XRD patterns showed that (CdS)₁₋ₓ (ZnTe)ₓ thin films were crystallized in pure hexagonal phase with (002) preferred orientation at x ≤ 0.2. While, x ≥ 0.8, these films were crystallized in pure cubic phase with (111) preferred orientation. For the composition x = 0.4 and 0.6, the cubic and the hexagonal phases were found to coexist in the system and the films become less preferentially oriented. However, CuSbS₂ phase belonging to orthorhombic crystal structure with small trace of Sb2S3 and Cu1.8S phases was formed after the films were annealed at 350 °C in pure nitrogen atmosphere for 60 min. SEM, FESEM and AFM were used to study morphological features of the films. Energy gap values of the films were calculated from the optical transmission spectra. Electrical properties were performed by Hall effect measurements with van der Pauw configuration. In addition, we fabricated (CdS)₀.₉(ZnTe)₀.₁/CuSbS₂ heterojunction thin films by thermal evaporation method deposited on ITO substrate. Electrical properties of the heterojunction were investigated by meaning of I-V and C-V characterizations. Under reverse bias condition, it showed a good photo-response under illumination by ELH halogen and UV lamps. This behavior indicates that the device may be a suitable candidate for white light and UV light photodiode applications.