Structural and optical characterisation of CdSe1−ySy

In this work presents the structural and optical characterisation of cadmium selenide sulphur (CdSe1−ySy) deposited by chemical bath deposition (CBD) technique at a deposited temperature of 20±2 °C varying the sulphur molar fraction from 0% to 42.13%, which is realized by varying the thiourea volume added to the growth solution in the range from 0 to 30 ml. The CdSe1−ySy chemical stoichiometry was determined by energy-dispersive X-ray spectroscopy (EDS). X-ray diffraction (XRD) analysis and Raman spectroscopy reveal that CdSe1−ySy deposited nanofilms showed hexagonal wurtzite crystalline phase. The average grain size range of the films was from 1.48–9.2 nm that was determined using the Scherrer–Debye equation from W(200) crystalline direction, which was confirmed by high resolution transmission electron microscopy (HRTEM). CdSe1−ySy band gap energy can be varied from 1.86 to 2.15 eV by varying the sulphur molar fraction incorporated in the nanofilms. The room temperature photoluminescence presents a dominant band about 3.0 eV that may be associated with the grain size of the nanoparticles.