Abstract
Using nebulizer spray pyrolysis method, we investigate the optoelectronic properties of Erbium (Er:2 %), Yttrium (Y:2 %) and Terbium (Tb:2 %) doped CdS thin films. The pure CdS film belongs to the II-IV semiconductor chalcogenide family, and it has good optical properties, making it appropriate for photo-detector applications. In addition, rare earth (RE) elements such as Erbium (Er), Yttrium (Y) and Terbium (Tb) doped CdS thin film is more suitable for photo sensing applications due to their good physical and optical properties. The polycrystalline structure of pure and doped CdS films with the structure of hexagonal and preferential orientation (002) was shown by structural analysis (XRD). In addition, the phase purity of RE doped CdS thin films was confirmed using Raman spectra. The direct bandgap values fell (2.52–2.47 eV) for the RE dopant, reaching a minimum for the film formed with RE of high ionic radius Tb. Three emission peaks were discovered in photoluminescence (PL) spectra: a strong dominant peak at 525 nm due to interband transitions and a peak with minimum intensity at 475 and 640 nm. With the exception of two RE materials, Er and Y, the CdS film coated with Tb had improved photo-sensitivity characteristics. Responsivity (3.32 AW−1), detectivity (2.82 × 1011 Jones), and external quantum efficiency (883 %) are the photo sensing values of Tb doped CdS film. The Tb coated films were found to exhibit good optical properties, making them suitable for photodetector applications.
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•Novel Er, Y and Tb doped CdS thin films-based photodetectors were developed using spray pyrolysis route.•Structural and vibrational studies confirm the phase of the grown Er, Y and Tb doped CdS films.•The direct bandgap values fell (2.52–2.47 eV) for the RE dopant, reaching a minimum for the film formed with RE of high ionic radius Tb.•With the exception of two RE materials, Er and Y, the CdS film coated with Tb had improved photo-sensitivity characteristics.•Responsivity (3.32 × 102A W−1), detectivity (2.82 × 1011 Jones), and external quantum efficiency (883 %) are the photo sensing values of Tb doped CdS film.