Investigation on the influence of Zn content on the structural, optical, morphological and electrical properties of ternary compound Cd1−xZnxS window layer for CdTe solar cell

Abstract

Ternary compound Cd[Formula: see text]Zn[Formula: see text]S thin films with different zinc compositions were deposited by the chemical bath deposition method, as a window layer for CdTe solar cells. The influence of Zn content on the structural, optical, morphological and electrical properties of Cd[Formula: see text]Zn[Formula: see text]S was studied from X-ray diffraction (XRD), SEM and UV-vis spectroscopy. We have considered the transformation of the crystal phase, change in the crystallite size and lattice parameters of Cd[Formula: see text]Zn[Formula: see text]S thin film with the change of Zn content through XRD studies. SEM measurement revealed that the size of Cd[Formula: see text]Zn[Formula: see text]S particles and surface roughness of thin film decreases with the increase of Zn composition. It was found that the band gap value obtained from transmittance spectrum became wider with the increase of Zn contents, which indicates the increase of film transmittance. The electrical resistivity of Cd[Formula: see text]Zn[Formula: see text]S thin films increased as Zn content [Formula: see text] increases. Finally, we measured the performances of CdTe solar cells using Cd[Formula: see text]Zn[Formula: see text]S thin films as a window layer and confirmed that desirable Zn content was in the range [Formula: see text] = 0.5-0.6.