Facile fabrication of Ag/Y:CdS/Ag thin films-based photodetectors with enhanced photodetection performance

Abstract Visible-light photodetectors are in great demand in current scenario for advanced optoelectronic devices. Hence, in current work we have fabricated the photodetectors based on Cadmium Sulfide (CdS) thin films with different contents of Yttrium (Y) doping. Hexagonal phase confirmation of the fabricated films was confirmed by X-ray diffraction and FT-Raman spectroscopy analyses. The crystallite size of grown films was determined and found within the range of 33 nm. Scanning electron microscopy was carried out to analyse the surface morphology of the films and reveals nanograins formation on the surface. Optical absorption/transmission/reflectance spectra were recorded up to near-infrared region and optical energy gap was estimated including several other optical parameters. PL spectra were recorded and an intense emission was observed at 542 ± 12 nm when excited at 350 and 450 nm both. The electrical characteristics were explored under dark and light conditions. The highest photoelectrical resistivity and sensitivity were observed for 5.0 wt.% which are around ∼9.45 × 107 Ω−1 and 55.07 % at 0.5 mW/cm2. However, the highest responsivity, external quantum efficiency and detectivity was observed for 3.0 wt.% and noticed around 0.83 A/W, 193.82 % and 4.28 × 1011 Jones, respectively. Outcomes reveal that the Y doping enhances the CdS photodetection nature.