Spray pressure variation effect on the properties of CdS thin films for photodetector applications

Herein, we report the photosensing property of CdS thin films. CdS thin films were coated onto glass substrates via a spray pyrolysis method using different spray pressures. Prepared films were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and optical and photoluminescence spectroscopy. XRD analysis demonstrated the growth of crystalline CdS films with crystallite sizes varying from 26 to 29 nm depending on the pressure. The SEM and EDAX analyses revealed nearly-stoichiometric CdS films with smooth surfaces and slight variation in grain morphology due to pressure changes. Optical measurements showed a direct bandgap varying from 2.37 eV to 2.42 eV due to pressure changes. A photodetector was also fabricated using the grown CdS films; the fabricated photodetector exhibited good performance depending on the spray pressure. A spray pressure of 1.5 GPa resulted in high photoresponsivity and external quantum efficiency.

Automated summary

CdS thin films with different photosensing properties were prepared using spray pyrolysis method at various spray pressures. The results showed that the properties of the CdS films were influenced by different spray pressures, with variations in crystallite sizes, bandgaps, and optical properties within a certain range of spray pressures. The photodetector fabricated using the CdS films exhibited good performance, with high photoresponsivity and external quantum efficiency achieved at a spray pressure of 1.5 GPa.