Role of Cu dilute on microstructures, optical, photoluminescence, magnetic and electrical properties of CdS film

Thin films of CdS1-xCux (with 0 ≤ x ≤ 0.10) were deposited using electron beam evaporation. Using XRD, EDX,
SEM and UV–Vis–NIR spectroscopy, the impact of [Cu]/[S] on the film properties was examined. The influences
of various concentrations of Cu are also elucidated on the optical parameters of the films. The XRD analysis
shows that the thin films of CdS1-xCux have been improved and have hexagonal polycrystalline structure with the
increase of Cu doping ratio. Additionally, the crystallite size is reduced while the micro-strain ε increases with
enhancement of the incorporation of Cu in CdS lattice. The envelope method was used to extract the optical
parameters of the undoped and Cu-doped CdS films. With the increase of Cu concentration, the energy optical
bandgap decreased, and the variation values of band gap could play an important role in solar cell applications.
Another optical parameters such as, dissipation factor and real/imaginary dielectric constant parts were evaluated
and demonstrated a strong Cu doping dependence. The shift observed in the photoluminescence spectra
emission band confirmed Cu’s substitution to CdS lattice. The measurements of magnetization using vibrating
sample magnetometer illustrated a hysteresis loop in Cu-doped CdS films, and confirmed the room temperature
ferromagnetism. Finally, the Hall effect results show that the pure CdS film corresponds to an n-type semiconductor
with a resistivity of 8.11 × 10-2 Ω cm and a carrier concentration of 29.6 × 1019 cm-3, and the CdS:Cu
film is a p-type semiconductor and the resistivity is reduced from 6.8 × 10-2 to 3.7 × 10-2 Ωcm, and the carrier
concentration